Austen Dicken
8404 lines
322 KiB
HTML
8404 lines
322 KiB
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<a name="SEC_Top"></a>
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<h1 class="settitle">ffmpeg Documentation</h1>
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<a name="SEC_Contents"></a>
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<h1>Table of Contents</h1>
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<div class="contents">
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<ul class="toc">
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<li><a name="toc-Synopsis" href="#Synopsis">1. Synopsis</a></li>
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<li><a name="toc-Description" href="#Description">2. Description</a></li>
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<li><a name="toc-Stream-selection" href="#Stream-selection">3. Stream selection</a></li>
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<li><a name="toc-Options-7" href="#Options-7">4. Options</a>
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<ul class="toc">
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<li><a name="toc-Stream-specifiers-1" href="#Stream-specifiers-1">4.1 Stream specifiers</a></li>
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<li><a name="toc-Generic-options" href="#Generic-options">4.2 Generic options</a></li>
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<li><a name="toc-AVOptions" href="#AVOptions">4.3 AVOptions</a></li>
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<li><a name="toc-Main-options" href="#Main-options">4.4 Main options</a></li>
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<li><a name="toc-Video-Options" href="#Video-Options">4.5 Video Options</a></li>
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<li><a name="toc-Advanced-Video-Options" href="#Advanced-Video-Options">4.6 Advanced Video Options</a></li>
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<li><a name="toc-Audio-Options" href="#Audio-Options">4.7 Audio Options</a></li>
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<li><a name="toc-Advanced-Audio-options_003a" href="#Advanced-Audio-options_003a">4.8 Advanced Audio options:</a></li>
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<li><a name="toc-Subtitle-options_003a" href="#Subtitle-options_003a">4.9 Subtitle options:</a></li>
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<li><a name="toc-Audio_002fVideo-grab-options" href="#Audio_002fVideo-grab-options">4.10 Audio/Video grab options</a></li>
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<li><a name="toc-Advanced-options" href="#Advanced-options">4.11 Advanced options</a></li>
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<li><a name="toc-Preset-files" href="#Preset-files">4.12 Preset files</a></li>
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</ul></li>
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<li><a name="toc-Tips" href="#Tips">5. Tips</a></li>
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<li><a name="toc-Examples" href="#Examples">6. Examples</a>
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<ul class="toc">
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<li><a name="toc-Preset-files-1" href="#Preset-files-1">6.1 Preset files</a></li>
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<li><a name="toc-Video-and-Audio-grabbing" href="#Video-and-Audio-grabbing">6.2 Video and Audio grabbing</a></li>
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<li><a name="toc-X11-grabbing" href="#X11-grabbing">6.3 X11 grabbing</a></li>
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<li><a name="toc-Video-and-Audio-file-format-conversion" href="#Video-and-Audio-file-format-conversion">6.4 Video and Audio file format conversion</a></li>
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</ul></li>
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<li><a name="toc-Expression-Evaluation" href="#Expression-Evaluation">7. Expression Evaluation</a></li>
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<li><a name="toc-Decoders" href="#Decoders">8. Decoders</a></li>
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<li><a name="toc-Video-Decoders" href="#Video-Decoders">9. Video Decoders</a>
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<ul class="toc">
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<li><a name="toc-rawvideo" href="#rawvideo">9.1 rawvideo</a>
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<ul class="toc">
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<li><a name="toc-Options-1" href="#Options-1">9.1.1 Options</a></li>
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</ul>
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</li>
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</ul></li>
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<li><a name="toc-Audio-Decoders" href="#Audio-Decoders">10. Audio Decoders</a>
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<ul class="toc">
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<li><a name="toc-ffwavesynth" href="#ffwavesynth">10.1 ffwavesynth</a></li>
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</ul></li>
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<li><a name="toc-Encoders" href="#Encoders">11. Encoders</a></li>
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<li><a name="toc-Audio-Encoders" href="#Audio-Encoders">12. Audio Encoders</a>
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<ul class="toc">
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<li><a name="toc-ac3-and-ac3_005ffixed" href="#ac3-and-ac3_005ffixed">12.1 ac3 and ac3_fixed</a>
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<ul class="toc">
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<li><a name="toc-AC_002d3-Metadata" href="#AC_002d3-Metadata">12.1.1 AC-3 Metadata</a>
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<ul class="toc">
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<li><a name="toc-Metadata-Control-Options" href="#Metadata-Control-Options">12.1.1.1 Metadata Control Options</a></li>
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<li><a name="toc-Downmix-Levels" href="#Downmix-Levels">12.1.1.2 Downmix Levels</a></li>
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<li><a name="toc-Audio-Production-Information" href="#Audio-Production-Information">12.1.1.3 Audio Production Information</a></li>
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<li><a name="toc-Other-Metadata-Options" href="#Other-Metadata-Options">12.1.1.4 Other Metadata Options</a></li>
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</ul></li>
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<li><a name="toc-Extended-Bitstream-Information" href="#Extended-Bitstream-Information">12.1.2 Extended Bitstream Information</a>
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<ul class="toc">
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<li><a name="toc-Extended-Bitstream-Information-_002d-Part-1" href="#Extended-Bitstream-Information-_002d-Part-1">12.1.2.1 Extended Bitstream Information - Part 1</a></li>
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<li><a name="toc-Extended-Bitstream-Information-_002d-Part-2" href="#Extended-Bitstream-Information-_002d-Part-2">12.1.2.2 Extended Bitstream Information - Part 2</a></li>
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</ul></li>
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<li><a name="toc-Other-AC_002d3-Encoding-Options" href="#Other-AC_002d3-Encoding-Options">12.1.3 Other AC-3 Encoding Options</a></li>
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<li><a name="toc-Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options" href="#Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options">12.1.4 Floating-Point-Only AC-3 Encoding Options</a></li>
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</ul>
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</li>
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</ul></li>
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<li><a name="toc-Video-Encoders" href="#Video-Encoders">13. Video Encoders</a>
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<ul class="toc">
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<li><a name="toc-libvpx" href="#libvpx">13.1 libvpx</a>
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<ul class="toc">
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<li><a name="toc-Options-5" href="#Options-5">13.1.1 Options</a></li>
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</ul></li>
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<li><a name="toc-libx264" href="#libx264">13.2 libx264</a>
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<ul class="toc">
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<li><a name="toc-Options-4" href="#Options-4">13.2.1 Options</a></li>
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</ul>
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</li>
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</ul></li>
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<li><a name="toc-Demuxers" href="#Demuxers">14. Demuxers</a>
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<ul class="toc">
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<li><a name="toc-image2-2" href="#image2-2">14.1 image2</a></li>
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<li><a name="toc-applehttp" href="#applehttp">14.2 applehttp</a></li>
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<li><a name="toc-sbg" href="#sbg">14.3 sbg</a></li>
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</ul></li>
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<li><a name="toc-Muxers" href="#Muxers">15. Muxers</a>
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<ul class="toc">
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<li><a name="toc-crc-1" href="#crc-1">15.1 crc</a></li>
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<li><a name="toc-framecrc-1" href="#framecrc-1">15.2 framecrc</a></li>
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<li><a name="toc-image2-1" href="#image2-1">15.3 image2</a></li>
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<li><a name="toc-mov" href="#mov">15.4 mov</a></li>
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<li><a name="toc-mpegts" href="#mpegts">15.5 mpegts</a></li>
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<li><a name="toc-null" href="#null">15.6 null</a></li>
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<li><a name="toc-matroska" href="#matroska">15.7 matroska</a></li>
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<li><a name="toc-segment" href="#segment">15.8 segment</a></li>
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</ul></li>
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<li><a name="toc-Input-Devices" href="#Input-Devices">16. Input Devices</a>
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<ul class="toc">
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<li><a name="toc-alsa-1" href="#alsa-1">16.1 alsa</a></li>
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<li><a name="toc-bktr" href="#bktr">16.2 bktr</a></li>
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<li><a name="toc-dshow" href="#dshow">16.3 dshow</a>
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<ul class="toc">
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<li><a name="toc-Options-2" href="#Options-2">16.3.1 Options</a></li>
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<li><a name="toc-Examples-7" href="#Examples-7">16.3.2 Examples</a></li>
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</ul></li>
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<li><a name="toc-dv1394" href="#dv1394">16.4 dv1394</a></li>
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<li><a name="toc-fbdev" href="#fbdev">16.5 fbdev</a></li>
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<li><a name="toc-jack" href="#jack">16.6 jack</a></li>
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<li><a name="toc-lavfi" href="#lavfi">16.7 lavfi</a>
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<ul class="toc">
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<li><a name="toc-Options" href="#Options">16.7.1 Options</a></li>
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<li><a name="toc-Examples-3" href="#Examples-3">16.7.2 Examples</a></li>
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</ul></li>
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<li><a name="toc-libdc1394" href="#libdc1394">16.8 libdc1394</a></li>
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<li><a name="toc-openal" href="#openal">16.9 openal</a>
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<ul class="toc">
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<li><a name="toc-Options-6" href="#Options-6">16.9.1 Options</a></li>
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<li><a name="toc-Examples-2" href="#Examples-2">16.9.2 Examples</a></li>
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</ul></li>
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<li><a name="toc-oss" href="#oss">16.10 oss</a></li>
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<li><a name="toc-pulse" href="#pulse">16.11 pulse</a>
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<ul class="toc">
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<li><a name="toc-server-AVOption" href="#server-AVOption">16.11.1 <var>server</var> AVOption</a></li>
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<li><a name="toc-name-AVOption" href="#name-AVOption">16.11.2 <var>name</var> AVOption</a></li>
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<li><a name="toc-stream_005fname-AVOption" href="#stream_005fname-AVOption">16.11.3 <var>stream_name</var> AVOption</a></li>
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<li><a name="toc-sample_005frate-AVOption" href="#sample_005frate-AVOption">16.11.4 <var>sample_rate</var> AVOption</a></li>
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<li><a name="toc-channels-AVOption" href="#channels-AVOption">16.11.5 <var>channels</var> AVOption</a></li>
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<li><a name="toc-frame_005fsize-AVOption" href="#frame_005fsize-AVOption">16.11.6 <var>frame_size</var> AVOption</a></li>
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<li><a name="toc-fragment_005fsize-AVOption" href="#fragment_005fsize-AVOption">16.11.7 <var>fragment_size</var> AVOption</a></li>
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</ul></li>
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<li><a name="toc-sndio" href="#sndio">16.12 sndio</a></li>
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<li><a name="toc-video4linux-and-video4linux2" href="#video4linux-and-video4linux2">16.13 video4linux and video4linux2</a></li>
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<li><a name="toc-vfwcap" href="#vfwcap">16.14 vfwcap</a></li>
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<li><a name="toc-x11grab" href="#x11grab">16.15 x11grab</a>
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<ul class="toc">
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<li><a name="toc-follow_005fmouse-AVOption" href="#follow_005fmouse-AVOption">16.15.1 <var>follow_mouse</var> AVOption</a></li>
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<li><a name="toc-show_005fregion-AVOption" href="#show_005fregion-AVOption">16.15.2 <var>show_region</var> AVOption</a></li>
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</ul>
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</li>
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</ul></li>
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<li><a name="toc-Output-Devices" href="#Output-Devices">17. Output Devices</a>
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<ul class="toc">
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<li><a name="toc-alsa" href="#alsa">17.1 alsa</a></li>
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<li><a name="toc-oss-1" href="#oss-1">17.2 oss</a></li>
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<li><a name="toc-sdl" href="#sdl">17.3 sdl</a>
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<ul class="toc">
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<li><a name="toc-Options-3" href="#Options-3">17.3.1 Options</a></li>
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<li><a name="toc-Examples-6" href="#Examples-6">17.3.2 Examples</a></li>
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</ul></li>
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<li><a name="toc-sndio-1" href="#sndio-1">17.4 sndio</a></li>
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</ul></li>
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<li><a name="toc-Protocols" href="#Protocols">18. Protocols</a>
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<ul class="toc">
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<li><a name="toc-applehttp-1" href="#applehttp-1">18.1 applehttp</a></li>
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<li><a name="toc-concat" href="#concat">18.2 concat</a></li>
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<li><a name="toc-file" href="#file">18.3 file</a></li>
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<li><a name="toc-gopher" href="#gopher">18.4 gopher</a></li>
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<li><a name="toc-http" href="#http">18.5 http</a></li>
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<li><a name="toc-mmst" href="#mmst">18.6 mmst</a></li>
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<li><a name="toc-mmsh" href="#mmsh">18.7 mmsh</a></li>
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<li><a name="toc-md5" href="#md5">18.8 md5</a></li>
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<li><a name="toc-pipe" href="#pipe">18.9 pipe</a></li>
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<li><a name="toc-rtmp" href="#rtmp">18.10 rtmp</a></li>
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<li><a name="toc-rtmp_002c-rtmpe_002c-rtmps_002c-rtmpt_002c-rtmpte" href="#rtmp_002c-rtmpe_002c-rtmps_002c-rtmpt_002c-rtmpte">18.11 rtmp, rtmpe, rtmps, rtmpt, rtmpte</a></li>
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<li><a name="toc-rtp" href="#rtp">18.12 rtp</a></li>
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<li><a name="toc-rtsp" href="#rtsp">18.13 rtsp</a></li>
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<li><a name="toc-sap" href="#sap">18.14 sap</a>
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<ul class="toc">
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<li><a name="toc-Muxer" href="#Muxer">18.14.1 Muxer</a></li>
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<li><a name="toc-Demuxer" href="#Demuxer">18.14.2 Demuxer</a></li>
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</ul></li>
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<li><a name="toc-tcp" href="#tcp">18.15 tcp</a></li>
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<li><a name="toc-udp" href="#udp">18.16 udp</a></li>
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</ul></li>
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<li><a name="toc-Bitstream-Filters" href="#Bitstream-Filters">19. Bitstream Filters</a>
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<ul class="toc">
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<li><a name="toc-aac_005fadtstoasc" href="#aac_005fadtstoasc">19.1 aac_adtstoasc</a></li>
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<li><a name="toc-chomp" href="#chomp">19.2 chomp</a></li>
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<li><a name="toc-dump_005fextradata" href="#dump_005fextradata">19.3 dump_extradata</a></li>
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<li><a name="toc-h264_005fmp4toannexb" href="#h264_005fmp4toannexb">19.4 h264_mp4toannexb</a></li>
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<li><a name="toc-imx_005fdump_005fheader" href="#imx_005fdump_005fheader">19.5 imx_dump_header</a></li>
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<li><a name="toc-mjpeg2jpeg" href="#mjpeg2jpeg">19.6 mjpeg2jpeg</a></li>
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<li><a name="toc-mjpega_005fdump_005fheader" href="#mjpega_005fdump_005fheader">19.7 mjpega_dump_header</a></li>
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<li><a name="toc-movsub" href="#movsub">19.8 movsub</a></li>
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<li><a name="toc-mp3_005fheader_005fcompress" href="#mp3_005fheader_005fcompress">19.9 mp3_header_compress</a></li>
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<li><a name="toc-mp3_005fheader_005fdecompress" href="#mp3_005fheader_005fdecompress">19.10 mp3_header_decompress</a></li>
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<li><a name="toc-noise" href="#noise">19.11 noise</a></li>
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<li><a name="toc-remove_005fextradata" href="#remove_005fextradata">19.12 remove_extradata</a></li>
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</ul></li>
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<li><a name="toc-Filtergraph-description" href="#Filtergraph-description">20. Filtergraph description</a>
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<ul class="toc">
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<li><a name="toc-Filtergraph-syntax" href="#Filtergraph-syntax">20.1 Filtergraph syntax</a></li>
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</ul></li>
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<li><a name="toc-Audio-Filters" href="#Audio-Filters">21. Audio Filters</a>
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<ul class="toc">
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<li><a name="toc-aconvert" href="#aconvert">21.1 aconvert</a></li>
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<li><a name="toc-aformat" href="#aformat">21.2 aformat</a></li>
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<li><a name="toc-amerge" href="#amerge">21.3 amerge</a></li>
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<li><a name="toc-anull" href="#anull">21.4 anull</a></li>
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<li><a name="toc-aresample" href="#aresample">21.5 aresample</a></li>
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<li><a name="toc-ashowinfo" href="#ashowinfo">21.6 ashowinfo</a></li>
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<li><a name="toc-asplit" href="#asplit">21.7 asplit</a></li>
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<li><a name="toc-astreamsync" href="#astreamsync">21.8 astreamsync</a></li>
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<li><a name="toc-earwax" href="#earwax">21.9 earwax</a></li>
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<li><a name="toc-pan" href="#pan">21.10 pan</a>
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<ul class="toc">
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<li><a name="toc-Mixing-examples" href="#Mixing-examples">21.10.1 Mixing examples</a></li>
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<li><a name="toc-Remapping-examples" href="#Remapping-examples">21.10.2 Remapping examples</a></li>
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</ul></li>
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<li><a name="toc-silencedetect" href="#silencedetect">21.11 silencedetect</a></li>
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<li><a name="toc-volume" href="#volume">21.12 volume</a>
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<ul class="toc">
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<li><a name="toc-Examples-1" href="#Examples-1">21.12.1 Examples</a></li>
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</ul>
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</li>
|
|
</ul></li>
|
|
<li><a name="toc-Audio-Sources" href="#Audio-Sources">22. Audio Sources</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-abuffer" href="#abuffer">22.1 abuffer</a></li>
|
|
<li><a name="toc-aevalsrc" href="#aevalsrc">22.2 aevalsrc</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-Examples-4" href="#Examples-4">22.2.1 Examples</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-amovie" href="#amovie">22.3 amovie</a></li>
|
|
<li><a name="toc-anullsrc" href="#anullsrc">22.4 anullsrc</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Audio-Sinks" href="#Audio-Sinks">23. Audio Sinks</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-abuffersink" href="#abuffersink">23.1 abuffersink</a></li>
|
|
<li><a name="toc-anullsink" href="#anullsink">23.2 anullsink</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Video-Filters" href="#Video-Filters">24. Video Filters</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-ass" href="#ass">24.1 ass</a></li>
|
|
<li><a name="toc-blackframe" href="#blackframe">24.2 blackframe</a></li>
|
|
<li><a name="toc-boxblur" href="#boxblur">24.3 boxblur</a></li>
|
|
<li><a name="toc-copy" href="#copy">24.4 copy</a></li>
|
|
<li><a name="toc-crop" href="#crop">24.5 crop</a></li>
|
|
<li><a name="toc-cropdetect" href="#cropdetect">24.6 cropdetect</a></li>
|
|
<li><a name="toc-delogo" href="#delogo">24.7 delogo</a></li>
|
|
<li><a name="toc-deshake" href="#deshake">24.8 deshake</a></li>
|
|
<li><a name="toc-drawbox" href="#drawbox">24.9 drawbox</a></li>
|
|
<li><a name="toc-drawtext" href="#drawtext">24.10 drawtext</a></li>
|
|
<li><a name="toc-fade" href="#fade">24.11 fade</a></li>
|
|
<li><a name="toc-fieldorder" href="#fieldorder">24.12 fieldorder</a></li>
|
|
<li><a name="toc-fifo" href="#fifo">24.13 fifo</a></li>
|
|
<li><a name="toc-format" href="#format">24.14 format</a></li>
|
|
<li><a name="toc-frei0r-1" href="#frei0r-1">24.15 frei0r</a></li>
|
|
<li><a name="toc-gradfun" href="#gradfun">24.16 gradfun</a></li>
|
|
<li><a name="toc-hflip" href="#hflip">24.17 hflip</a></li>
|
|
<li><a name="toc-hqdn3d" href="#hqdn3d">24.18 hqdn3d</a></li>
|
|
<li><a name="toc-lut_002c-lutrgb_002c-lutyuv" href="#lut_002c-lutrgb_002c-lutyuv">24.19 lut, lutrgb, lutyuv</a></li>
|
|
<li><a name="toc-mp" href="#mp">24.20 mp</a></li>
|
|
<li><a name="toc-negate" href="#negate">24.21 negate</a></li>
|
|
<li><a name="toc-noformat" href="#noformat">24.22 noformat</a></li>
|
|
<li><a name="toc-null-1" href="#null-1">24.23 null</a></li>
|
|
<li><a name="toc-ocv" href="#ocv">24.24 ocv</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-dilate-1" href="#dilate-1">24.24.1 dilate</a></li>
|
|
<li><a name="toc-erode" href="#erode">24.24.2 erode</a></li>
|
|
<li><a name="toc-smooth" href="#smooth">24.24.3 smooth</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-overlay-1" href="#overlay-1">24.25 overlay</a></li>
|
|
<li><a name="toc-pad" href="#pad">24.26 pad</a></li>
|
|
<li><a name="toc-pixdesctest" href="#pixdesctest">24.27 pixdesctest</a></li>
|
|
<li><a name="toc-scale" href="#scale">24.28 scale</a></li>
|
|
<li><a name="toc-select" href="#select">24.29 select</a></li>
|
|
<li><a name="toc-setdar-1" href="#setdar-1">24.30 setdar</a></li>
|
|
<li><a name="toc-setpts" href="#setpts">24.31 setpts</a></li>
|
|
<li><a name="toc-setsar-1" href="#setsar-1">24.32 setsar</a></li>
|
|
<li><a name="toc-settb" href="#settb">24.33 settb</a></li>
|
|
<li><a name="toc-showinfo" href="#showinfo">24.34 showinfo</a></li>
|
|
<li><a name="toc-slicify" href="#slicify">24.35 slicify</a></li>
|
|
<li><a name="toc-split" href="#split">24.36 split</a></li>
|
|
<li><a name="toc-thumbnail" href="#thumbnail">24.37 thumbnail</a></li>
|
|
<li><a name="toc-tinterlace" href="#tinterlace">24.38 tinterlace</a></li>
|
|
<li><a name="toc-transpose" href="#transpose">24.39 transpose</a></li>
|
|
<li><a name="toc-unsharp" href="#unsharp">24.40 unsharp</a></li>
|
|
<li><a name="toc-vflip" href="#vflip">24.41 vflip</a></li>
|
|
<li><a name="toc-yadif" href="#yadif">24.42 yadif</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Video-Sources" href="#Video-Sources">25. Video Sources</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-buffer" href="#buffer">25.1 buffer</a></li>
|
|
<li><a name="toc-cellauto" href="#cellauto">25.2 cellauto</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-Examples-5" href="#Examples-5">25.2.1 Examples</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-color" href="#color">25.3 color</a></li>
|
|
<li><a name="toc-movie" href="#movie">25.4 movie</a></li>
|
|
<li><a name="toc-mptestsrc" href="#mptestsrc">25.5 mptestsrc</a></li>
|
|
<li><a name="toc-frei0r_005fsrc" href="#frei0r_005fsrc">25.6 frei0r_src</a></li>
|
|
<li><a name="toc-life" href="#life">25.7 life</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-Examples-8" href="#Examples-8">25.7.1 Examples</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-nullsrc_002c-rgbtestsrc_002c-testsrc" href="#nullsrc_002c-rgbtestsrc_002c-testsrc">25.8 nullsrc, rgbtestsrc, testsrc</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Video-Sinks" href="#Video-Sinks">26. Video Sinks</a>
|
|
<ul class="toc">
|
|
<li><a name="toc-buffersink" href="#buffersink">26.1 buffersink</a></li>
|
|
<li><a name="toc-nullsink" href="#nullsink">26.2 nullsink</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Metadata" href="#Metadata">27. Metadata</a></li>
|
|
</ul>
|
|
</div>
|
|
|
|
<a name="Synopsis"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Synopsis">1. Synopsis</a></h1>
|
|
|
|
<p>The generic syntax is:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg [global options] [[infile options][‘<samp>-i</samp>’ <var>infile</var>]]... {[outfile options] <var>outfile</var>}...
|
|
</pre></td></tr></table>
|
|
|
|
<a name="Description"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Description">2. Description</a></h1>
|
|
|
|
<p>ffmpeg is a very fast video and audio converter that can also grab from
|
|
a live audio/video source. It can also convert between arbitrary sample
|
|
rates and resize video on the fly with a high quality polyphase filter.
|
|
</p>
|
|
<p>ffmpeg reads from an arbitrary number of input "files" (which can be regular
|
|
files, pipes, network streams, grabbing devices, etc.), specified by the
|
|
<code>-i</code> option, and writes to an arbitrary number of output "files", which are
|
|
specified by a plain output filename. Anything found on the command line which
|
|
cannot be interpreted as an option is considered to be an output filename.
|
|
</p>
|
|
<p>Each input or output file can in principle contain any number of streams of
|
|
different types (video/audio/subtitle/attachment/data). Allowed number and/or
|
|
types of streams can be limited by the container format. Selecting, which
|
|
streams from which inputs go into output, is done either automatically or with
|
|
the <code>-map</code> option (see the Stream selection chapter).
|
|
</p>
|
|
<p>To refer to input files in options, you must use their indices (0-based). E.g.
|
|
the first input file is <code>0</code>, the second is <code>1</code> etc. Similarly, streams
|
|
within a file are referred to by their indices. E.g. <code>2:3</code> refers to the
|
|
fourth stream in the third input file. See also the Stream specifiers chapter.
|
|
</p>
|
|
<p>As a general rule, options are applied to the next specified
|
|
file. Therefore, order is important, and you can have the same
|
|
option on the command line multiple times. Each occurrence is
|
|
then applied to the next input or output file.
|
|
Exceptions from this rule are the global options (e.g. verbosity level),
|
|
which should be specified first.
|
|
</p>
|
|
<p>Do not mix input and output files – first specify all input files, then all
|
|
output files. Also do not mix options which belong to different files. All
|
|
options apply ONLY to the next input or output file and are reset between files.
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
To set the video bitrate of the output file to 64kbit/s:
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i input.avi -b:v 64k output.avi
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
To force the frame rate of the output file to 24 fps:
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i input.avi -r 24 output.avi
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
To force the frame rate of the input file (valid for raw formats only)
|
|
to 1 fps and the frame rate of the output file to 24 fps:
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -r 1 -i input.m2v -r 24 output.avi
|
|
</pre></td></tr></table>
|
|
</li></ul>
|
|
|
|
<p>The format option may be needed for raw input files.
|
|
</p>
|
|
|
|
<a name="Stream-selection"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Stream-selection">3. Stream selection</a></h1>
|
|
|
|
<p>By default ffmpeg includes only one stream of each type (video, audio, subtitle)
|
|
present in the input files and adds them to each output file. It picks the
|
|
"best" of each based upon the following criteria; for video it is the stream
|
|
with the highest resolution, for audio the stream with the most channels, for
|
|
subtitle it’s the first subtitle stream. In the case where several streams of
|
|
the same type rate equally, the lowest numbered stream is chosen.
|
|
</p>
|
|
<p>You can disable some of those defaults by using <code>-vn/-an/-sn</code> options. For
|
|
full manual control, use the <code>-map</code> option, which disables the defaults just
|
|
described.
|
|
</p>
|
|
|
|
<a name="Options-7"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Options-7">4. Options</a></h1>
|
|
|
|
<p>All the numerical options, if not specified otherwise, accept in input
|
|
a string representing a number, which may contain one of the
|
|
International System number postfixes, for example ’K’, ’M’, ’G’.
|
|
If ’i’ is appended after the postfix, powers of 2 are used instead of
|
|
powers of 10. The ’B’ postfix multiplies the value for 8, and can be
|
|
appended after another postfix or used alone. This allows using for
|
|
example ’KB’, ’MiB’, ’G’ and ’B’ as postfix.
|
|
</p>
|
|
<p>Options which do not take arguments are boolean options, and set the
|
|
corresponding value to true. They can be set to false by prefixing
|
|
with "no" the option name, for example using "-nofoo" in the
|
|
command line will set to false the boolean option with name "foo".
|
|
</p>
|
|
<p><a name="Stream-specifiers"></a>
|
|
</p><a name="Stream-specifiers-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Stream-specifiers-1">4.1 Stream specifiers</a></h2>
|
|
<p>Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
|
|
are used to precisely specify which stream(s) does a given option belong to.
|
|
</p>
|
|
<p>A stream specifier is a string generally appended to the option name and
|
|
separated from it by a colon. E.g. <code>-codec:a:1 ac3</code> option contains
|
|
<code>a:1</code> stream specifer, which matches the second audio stream. Therefore it
|
|
would select the ac3 codec for the second audio stream.
|
|
</p>
|
|
<p>A stream specifier can match several stream, the option is then applied to all
|
|
of them. E.g. the stream specifier in <code>-b:a 128k</code> matches all audio
|
|
streams.
|
|
</p>
|
|
<p>An empty stream specifier matches all streams, for example <code>-codec copy</code>
|
|
or <code>-codec: copy</code> would copy all the streams without reencoding.
|
|
</p>
|
|
<p>Possible forms of stream specifiers are:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp><var>stream_index</var></samp>’</dt>
|
|
<dd><p>Matches the stream with this index. E.g. <code>-threads:1 4</code> would set the
|
|
thread count for the second stream to 4.
|
|
</p></dd>
|
|
<dt> ‘<samp><var>stream_type</var>[:<var>stream_index</var>]</samp>’</dt>
|
|
<dd><p><var>stream_type</var> is one of: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
|
|
’d’ for data and ’t’ for attachments. If <var>stream_index</var> is given, then
|
|
matches stream number <var>stream_index</var> of this type. Otherwise matches all
|
|
streams of this type.
|
|
</p></dd>
|
|
<dt> ‘<samp>p:<var>program_id</var>[:<var>stream_index</var>]</samp>’</dt>
|
|
<dd><p>If <var>stream_index</var> is given, then matches stream number <var>stream_index</var> in
|
|
program with id <var>program_id</var>. Otherwise matches all streams in this program.
|
|
</p></dd>
|
|
</dl>
|
|
<a name="Generic-options"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Generic-options">4.2 Generic options</a></h2>
|
|
|
|
<p>These options are shared amongst the av* tools.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-L</samp>’</dt>
|
|
<dd><p>Show license.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-h, -?, -help, --help</samp>’</dt>
|
|
<dd><p>Show help.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-version</samp>’</dt>
|
|
<dd><p>Show version.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-formats</samp>’</dt>
|
|
<dd><p>Show available formats.
|
|
</p>
|
|
<p>The fields preceding the format names have the following meanings:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>D</samp>’</dt>
|
|
<dd><p>Decoding available
|
|
</p></dd>
|
|
<dt> ‘<samp>E</samp>’</dt>
|
|
<dd><p>Encoding available
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-codecs</samp>’</dt>
|
|
<dd><p>Show available codecs.
|
|
</p>
|
|
<p>The fields preceding the codec names have the following meanings:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>D</samp>’</dt>
|
|
<dd><p>Decoding available
|
|
</p></dd>
|
|
<dt> ‘<samp>E</samp>’</dt>
|
|
<dd><p>Encoding available
|
|
</p></dd>
|
|
<dt> ‘<samp>V/A/S</samp>’</dt>
|
|
<dd><p>Video/audio/subtitle codec
|
|
</p></dd>
|
|
<dt> ‘<samp>S</samp>’</dt>
|
|
<dd><p>Codec supports slices
|
|
</p></dd>
|
|
<dt> ‘<samp>D</samp>’</dt>
|
|
<dd><p>Codec supports direct rendering
|
|
</p></dd>
|
|
<dt> ‘<samp>T</samp>’</dt>
|
|
<dd><p>Codec can handle input truncated at random locations instead of only at frame boundaries
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-bsfs</samp>’</dt>
|
|
<dd><p>Show available bitstream filters.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-protocols</samp>’</dt>
|
|
<dd><p>Show available protocols.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-filters</samp>’</dt>
|
|
<dd><p>Show available libavfilter filters.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-pix_fmts</samp>’</dt>
|
|
<dd><p>Show available pixel formats.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-sample_fmts</samp>’</dt>
|
|
<dd><p>Show available sample formats.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-loglevel <var>loglevel</var> | -v <var>loglevel</var></samp>’</dt>
|
|
<dd><p>Set the logging level used by the library.
|
|
<var>loglevel</var> is a number or a string containing one of the following values:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>quiet</samp>’</dt>
|
|
<dt> ‘<samp>panic</samp>’</dt>
|
|
<dt> ‘<samp>fatal</samp>’</dt>
|
|
<dt> ‘<samp>error</samp>’</dt>
|
|
<dt> ‘<samp>warning</samp>’</dt>
|
|
<dt> ‘<samp>info</samp>’</dt>
|
|
<dt> ‘<samp>verbose</samp>’</dt>
|
|
<dt> ‘<samp>debug</samp>’</dt>
|
|
</dl>
|
|
|
|
<p>By default the program logs to stderr, if coloring is supported by the
|
|
terminal, colors are used to mark errors and warnings. Log coloring
|
|
can be disabled setting the environment variable
|
|
<code>AV_LOG_FORCE_NOCOLOR</code> or <code>NO_COLOR</code>, or can be forced setting
|
|
the environment variable <code>AV_LOG_FORCE_COLOR</code>.
|
|
The use of the environment variable <code>NO_COLOR</code> is deprecated and
|
|
will be dropped in a following FFmpeg version.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-report</samp>’</dt>
|
|
<dd><p>Dump full command line and console output to a file named
|
|
<code><var>program</var>-<var>YYYYMMDD</var>-<var>HHMMSS</var>.log</code> in the current
|
|
directory.
|
|
This file can be useful for bug reports.
|
|
It also implies <code>-loglevel verbose</code>.
|
|
</p>
|
|
<p>Note: setting the environment variable <code>FFREPORT</code> to any value has the
|
|
same effect.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="AVOptions"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-AVOptions">4.3 AVOptions</a></h2>
|
|
|
|
<p>These options are provided directly by the libavformat, libavdevice and
|
|
libavcodec libraries. To see the list of available AVOptions, use the
|
|
‘<samp>-help</samp>’ option. They are separated into two categories:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>generic</samp>’</dt>
|
|
<dd><p>These options can be set for any container, codec or device. Generic options
|
|
are listed under AVFormatContext options for containers/devices and under
|
|
AVCodecContext options for codecs.
|
|
</p></dd>
|
|
<dt> ‘<samp>private</samp>’</dt>
|
|
<dd><p>These options are specific to the given container, device or codec. Private
|
|
options are listed under their corresponding containers/devices/codecs.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>For example to write an ID3v2.3 header instead of a default ID3v2.4 to
|
|
an MP3 file, use the ‘<samp>id3v2_version</samp>’ private option of the MP3
|
|
muxer:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i input.flac -id3v2_version 3 out.mp3
|
|
</pre></td></tr></table>
|
|
|
|
<p>All codec AVOptions are obviously per-stream, so the chapter on stream
|
|
specifiers applies to them
|
|
</p>
|
|
<p>Note ‘<samp>-nooption</samp>’ syntax cannot be used for boolean AVOptions,
|
|
use ‘<samp>-option 0</samp>’/‘<samp>-option 1</samp>’.
|
|
</p>
|
|
<p>Note2 old undocumented way of specifying per-stream AVOptions by prepending
|
|
v/a/s to the options name is now obsolete and will be removed soon.
|
|
</p>
|
|
<a name="Main-options"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Main-options">4.4 Main options</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-f <var>fmt</var> (<em>input/output</em>)</samp>’</dt>
|
|
<dd><p>Force input or output file format. The format is normally auto detected for input
|
|
files and guessed from file extension for output files, so this option is not
|
|
needed in most cases.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-i <var>filename</var> (<em>input</em>)</samp>’</dt>
|
|
<dd><p>input file name
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-y (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Overwrite output files without asking.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-n (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Do not overwrite output files but exit if file exists.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-c[:<var>stream_specifier</var>] <var>codec</var> (<em>input/output,per-stream</em>)</samp>’</dt>
|
|
<dt> ‘<samp>-codec[:<var>stream_specifier</var>] <var>codec</var> (<em>input/output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Select an encoder (when used before an output file) or a decoder (when used
|
|
before an input file) for one or more streams. <var>codec</var> is the name of a
|
|
decoder/encoder or a special value <code>copy</code> (output only) to indicate that
|
|
the stream is not to be re-encoded.
|
|
</p>
|
|
<p>For example
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
|
|
</pre></td></tr></table>
|
|
<p>encodes all video streams with libx264 and copies all audio streams.
|
|
</p>
|
|
<p>For each stream, the last matching <code>c</code> option is applied, so
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
|
|
</pre></td></tr></table>
|
|
<p>will copy all the streams except the second video, which will be encoded with
|
|
libx264, and the 138th audio, which will be encoded with libvorbis.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-t <var>duration</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Stop writing the output after its duration reaches <var>duration</var>.
|
|
<var>duration</var> may be a number in seconds, or in <code>hh:mm:ss[.xxx]</code> form.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-fs <var>limit_size</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Set the file size limit.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-ss <var>position</var> (<em>input/output</em>)</samp>’</dt>
|
|
<dd><p>When used as an input option (before <code>-i</code>), seeks in this input file to
|
|
<var>position</var>. When used as an output option (before an output filename),
|
|
decodes but discards input until the timestamps reach <var>position</var>. This is
|
|
slower, but more accurate.
|
|
</p>
|
|
<p><var>position</var> may be either in seconds or in <code>hh:mm:ss[.xxx]</code> form.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-itsoffset <var>offset</var> (<em>input</em>)</samp>’</dt>
|
|
<dd><p>Set the input time offset in seconds.
|
|
<code>[-]hh:mm:ss[.xxx]</code> syntax is also supported.
|
|
The offset is added to the timestamps of the input files.
|
|
Specifying a positive offset means that the corresponding
|
|
streams are delayed by <var>offset</var> seconds.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-timestamp <var>time</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Set the recording timestamp in the container.
|
|
The syntax for <var>time</var> is:
|
|
</p><table><tr><td> </td><td><pre class="example">now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
|
|
</pre></td></tr></table>
|
|
<p>If the value is "now" it takes the current time.
|
|
Time is local time unless ’Z’ or ’z’ is appended, in which case it is
|
|
interpreted as UTC.
|
|
If the year-month-day part is not specified it takes the current
|
|
year-month-day.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-metadata[:metadata_specifier] <var>key</var>=<var>value</var> (<em>output,per-metadata</em>)</samp>’</dt>
|
|
<dd><p>Set a metadata key/value pair.
|
|
</p>
|
|
<p>An optional <var>metadata_specifier</var> may be given to set metadata
|
|
on streams or chapters. See <code>-map_metadata</code> documentation for
|
|
details.
|
|
</p>
|
|
<p>This option overrides metadata set with <code>-map_metadata</code>. It is
|
|
also possible to delete metadata by using an empty value.
|
|
</p>
|
|
<p>For example, for setting the title in the output file:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -metadata title="my title" out.flv
|
|
</pre></td></tr></table>
|
|
|
|
<p>To set the language of the first audio stream:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -metadata:s:a:1 language=eng OUTPUT
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-target <var>type</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Specify target file type (<code>vcd</code>, <code>svcd</code>, <code>dvd</code>, <code>dv</code>,
|
|
<code>dv50</code>). <var>type</var> may be prefixed with <code>pal-</code>, <code>ntsc-</code> or
|
|
<code>film-</code> to use the corresponding standard. All the format options
|
|
(bitrate, codecs, buffer sizes) are then set automatically. You can just type:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Nevertheless you can specify additional options as long as you know
|
|
they do not conflict with the standard, as in:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-dframes <var>number</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Set the number of data frames to record. This is an alias for <code>-frames:d</code>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-frames[:<var>stream_specifier</var>] <var>framecount</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Stop writing to the stream after <var>framecount</var> frames.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-q[:<var>stream_specifier</var>] <var>q</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dt> ‘<samp>-qscale[:<var>stream_specifier</var>] <var>q</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Use fixed quality scale (VBR). The meaning of <var>q</var> is
|
|
codec-dependent.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-filter[:<var>stream_specifier</var>] <var>filter_graph</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p><var>filter_graph</var> is a description of the filter graph to apply to
|
|
the stream. Use <code>-filters</code> to show all the available filters
|
|
(including also sources and sinks).
|
|
</p></dd>
|
|
<dt> ‘<samp>-pre[:<var>stream_specifier</var>] <var>preset_name</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Specify the preset for matching stream(s).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-stats (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Print encoding progress/statistics. On by default.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-attach <var>filename</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Add an attachment to the output file. This is supported by a few formats
|
|
like Matroska for e.g. fonts used in rendering subtitles. Attachments
|
|
are implemented as a specific type of stream, so this option will add
|
|
a new stream to the file. It is then possible to use per-stream options
|
|
on this stream in the usual way. Attachment streams created with this
|
|
option will be created after all the other streams (i.e. those created
|
|
with <code>-map</code> or automatic mappings).
|
|
</p>
|
|
<p>Note that for Matroska you also have to set the mimetype metadata tag:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
|
|
</pre></td></tr></table>
|
|
<p>(assuming that the attachment stream will be third in the output file).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-dump_attachment[:<var>stream_specifier</var>] <var>filename</var> (<em>input,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Extract the matching attachment stream into a file named <var>filename</var>. If
|
|
<var>filename</var> is empty, then the value of the <code>filename</code> metadata tag
|
|
will be used.
|
|
</p>
|
|
<p>E.g. to extract the first attachment to a file named ’out.ttf’:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -dump_attachment:t:0 out.ttf INPUT
|
|
</pre></td></tr></table>
|
|
<p>To extract all attachments to files determined by the <code>filename</code> tag:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -dump_attachment:t "" INPUT
|
|
</pre></td></tr></table>
|
|
|
|
<p>Technical note – attachments are implemented as codec extradata, so this
|
|
option can actually be used to extract extradata from any stream, not just
|
|
attachments.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Video-Options"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Video-Options">4.5 Video Options</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-vframes <var>number</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Set the number of video frames to record. This is an alias for <code>-frames:v</code>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-r[:<var>stream_specifier</var>] <var>fps</var> (<em>input/output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set frame rate (Hz value, fraction or abbreviation), (default = 25).
|
|
</p></dd>
|
|
<dt> ‘<samp>-s[:<var>stream_specifier</var>] <var>size</var> (<em>input/output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set frame size. The format is ‘<samp>wxh</samp>’ (default - same as source).
|
|
The following abbreviations are recognized:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>sqcif</samp>’</dt>
|
|
<dd><p>128x96
|
|
</p></dd>
|
|
<dt> ‘<samp>qcif</samp>’</dt>
|
|
<dd><p>176x144
|
|
</p></dd>
|
|
<dt> ‘<samp>cif</samp>’</dt>
|
|
<dd><p>352x288
|
|
</p></dd>
|
|
<dt> ‘<samp>4cif</samp>’</dt>
|
|
<dd><p>704x576
|
|
</p></dd>
|
|
<dt> ‘<samp>16cif</samp>’</dt>
|
|
<dd><p>1408x1152
|
|
</p></dd>
|
|
<dt> ‘<samp>qqvga</samp>’</dt>
|
|
<dd><p>160x120
|
|
</p></dd>
|
|
<dt> ‘<samp>qvga</samp>’</dt>
|
|
<dd><p>320x240
|
|
</p></dd>
|
|
<dt> ‘<samp>vga</samp>’</dt>
|
|
<dd><p>640x480
|
|
</p></dd>
|
|
<dt> ‘<samp>svga</samp>’</dt>
|
|
<dd><p>800x600
|
|
</p></dd>
|
|
<dt> ‘<samp>xga</samp>’</dt>
|
|
<dd><p>1024x768
|
|
</p></dd>
|
|
<dt> ‘<samp>uxga</samp>’</dt>
|
|
<dd><p>1600x1200
|
|
</p></dd>
|
|
<dt> ‘<samp>qxga</samp>’</dt>
|
|
<dd><p>2048x1536
|
|
</p></dd>
|
|
<dt> ‘<samp>sxga</samp>’</dt>
|
|
<dd><p>1280x1024
|
|
</p></dd>
|
|
<dt> ‘<samp>qsxga</samp>’</dt>
|
|
<dd><p>2560x2048
|
|
</p></dd>
|
|
<dt> ‘<samp>hsxga</samp>’</dt>
|
|
<dd><p>5120x4096
|
|
</p></dd>
|
|
<dt> ‘<samp>wvga</samp>’</dt>
|
|
<dd><p>852x480
|
|
</p></dd>
|
|
<dt> ‘<samp>wxga</samp>’</dt>
|
|
<dd><p>1366x768
|
|
</p></dd>
|
|
<dt> ‘<samp>wsxga</samp>’</dt>
|
|
<dd><p>1600x1024
|
|
</p></dd>
|
|
<dt> ‘<samp>wuxga</samp>’</dt>
|
|
<dd><p>1920x1200
|
|
</p></dd>
|
|
<dt> ‘<samp>woxga</samp>’</dt>
|
|
<dd><p>2560x1600
|
|
</p></dd>
|
|
<dt> ‘<samp>wqsxga</samp>’</dt>
|
|
<dd><p>3200x2048
|
|
</p></dd>
|
|
<dt> ‘<samp>wquxga</samp>’</dt>
|
|
<dd><p>3840x2400
|
|
</p></dd>
|
|
<dt> ‘<samp>whsxga</samp>’</dt>
|
|
<dd><p>6400x4096
|
|
</p></dd>
|
|
<dt> ‘<samp>whuxga</samp>’</dt>
|
|
<dd><p>7680x4800
|
|
</p></dd>
|
|
<dt> ‘<samp>cga</samp>’</dt>
|
|
<dd><p>320x200
|
|
</p></dd>
|
|
<dt> ‘<samp>ega</samp>’</dt>
|
|
<dd><p>640x350
|
|
</p></dd>
|
|
<dt> ‘<samp>hd480</samp>’</dt>
|
|
<dd><p>852x480
|
|
</p></dd>
|
|
<dt> ‘<samp>hd720</samp>’</dt>
|
|
<dd><p>1280x720
|
|
</p></dd>
|
|
<dt> ‘<samp>hd1080</samp>’</dt>
|
|
<dd><p>1920x1080
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-aspect[:<var>stream_specifier</var>] <var>aspect</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set the video display aspect ratio specified by <var>aspect</var>.
|
|
</p>
|
|
<p><var>aspect</var> can be a floating point number string, or a string of the
|
|
form <var>num</var>:<var>den</var>, where <var>num</var> and <var>den</var> are the
|
|
numerator and denominator of the aspect ratio. For example "4:3",
|
|
"16:9", "1.3333", and "1.7777" are valid argument values.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-croptop <var>size</var></samp>’</dt>
|
|
<dt> ‘<samp>-cropbottom <var>size</var></samp>’</dt>
|
|
<dt> ‘<samp>-cropleft <var>size</var></samp>’</dt>
|
|
<dt> ‘<samp>-cropright <var>size</var></samp>’</dt>
|
|
<dd><p>All the crop options have been removed. Use -vf
|
|
crop=width:height:x:y instead.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-padtop <var>size</var></samp>’</dt>
|
|
<dt> ‘<samp>-padbottom <var>size</var></samp>’</dt>
|
|
<dt> ‘<samp>-padleft <var>size</var></samp>’</dt>
|
|
<dt> ‘<samp>-padright <var>size</var></samp>’</dt>
|
|
<dt> ‘<samp>-padcolor <var>hex_color</var></samp>’</dt>
|
|
<dd><p>All the pad options have been removed. Use -vf
|
|
pad=width:height:x:y:color instead.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-vn (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Disable video recording.
|
|
</p></dd>
|
|
<dt> ‘<samp>-bt <var>tolerance</var></samp>’</dt>
|
|
<dd><p>Set video bitrate tolerance (in bits, default 4000k).
|
|
Has a minimum value of: (target_bitrate/target_framerate).
|
|
In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
|
|
willing to deviate from the target average bitrate value. This is
|
|
not related to min/max bitrate. Lowering tolerance too much has
|
|
an adverse effect on quality.
|
|
</p></dd>
|
|
<dt> ‘<samp>-maxrate <var>bitrate</var></samp>’</dt>
|
|
<dd><p>Set max video bitrate (in bit/s).
|
|
Requires -bufsize to be set.
|
|
</p></dd>
|
|
<dt> ‘<samp>-minrate <var>bitrate</var></samp>’</dt>
|
|
<dd><p>Set min video bitrate (in bit/s).
|
|
Most useful in setting up a CBR encode:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i myfile.avi -b:v 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
|
|
</pre></td></tr></table>
|
|
<p>It is of little use elsewise.
|
|
</p></dd>
|
|
<dt> ‘<samp>-bufsize <var>size</var></samp>’</dt>
|
|
<dd><p>Set video buffer verifier buffer size (in bits).
|
|
</p></dd>
|
|
<dt> ‘<samp>-vcodec <var>codec</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Set the video codec. This is an alias for <code>-codec:v</code>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-same_quant</samp>’</dt>
|
|
<dd><p>Use same quantizer as source (implies VBR).
|
|
</p>
|
|
<p>Note that this is NOT SAME QUALITY. Do not use this option unless you know you
|
|
need it.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-pass <var>n</var></samp>’</dt>
|
|
<dd><p>Select the pass number (1 or 2). It is used to do two-pass
|
|
video encoding. The statistics of the video are recorded in the first
|
|
pass into a log file (see also the option -passlogfile),
|
|
and in the second pass that log file is used to generate the video
|
|
at the exact requested bitrate.
|
|
On pass 1, you may just deactivate audio and set output to null,
|
|
examples for Windows and Unix:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
|
|
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-passlogfile <var>prefix</var> (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Set two-pass log file name prefix to <var>prefix</var>, the default file name
|
|
prefix is “ffmpeg2pass”. The complete file name will be
|
|
‘<tt>PREFIX-N.log</tt>’, where N is a number specific to the output
|
|
stream
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-vlang <var>code</var></samp>’</dt>
|
|
<dd><p>Set the ISO 639 language code (3 letters) of the current video stream.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-vf <var>filter_graph</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p><var>filter_graph</var> is a description of the filter graph to apply to
|
|
the input video.
|
|
Use the option "-filters" to show all the available filters (including
|
|
also sources and sinks). This is an alias for <code>-filter:v</code>.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Advanced-Video-Options"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Advanced-Video-Options">4.6 Advanced Video Options</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-pix_fmt[:<var>stream_specifier</var>] <var>format</var> (<em>input/output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set pixel format. Use <code>-pix_fmts</code> to show all the supported
|
|
pixel formats.
|
|
</p></dd>
|
|
<dt> ‘<samp>-sws_flags <var>flags</var> (<em>input/output</em>)</samp>’</dt>
|
|
<dd><p>Set SwScaler flags.
|
|
</p></dd>
|
|
<dt> ‘<samp>-g <var>gop_size</var></samp>’</dt>
|
|
<dd><p>Set the group of pictures size.
|
|
</p></dd>
|
|
<dt> ‘<samp>-intra</samp>’</dt>
|
|
<dd><p>deprecated, use -g 1
|
|
</p></dd>
|
|
<dt> ‘<samp>-vdt <var>n</var></samp>’</dt>
|
|
<dd><p>Discard threshold.
|
|
</p></dd>
|
|
<dt> ‘<samp>-qmin <var>q</var></samp>’</dt>
|
|
<dd><p>minimum video quantizer scale (VBR)
|
|
</p></dd>
|
|
<dt> ‘<samp>-qmax <var>q</var></samp>’</dt>
|
|
<dd><p>maximum video quantizer scale (VBR)
|
|
</p></dd>
|
|
<dt> ‘<samp>-qdiff <var>q</var></samp>’</dt>
|
|
<dd><p>maximum difference between the quantizer scales (VBR)
|
|
</p></dd>
|
|
<dt> ‘<samp>-qblur <var>blur</var></samp>’</dt>
|
|
<dd><p>video quantizer scale blur (VBR) (range 0.0 - 1.0)
|
|
</p></dd>
|
|
<dt> ‘<samp>-qcomp <var>compression</var></samp>’</dt>
|
|
<dd><p>video quantizer scale compression (VBR) (default 0.5).
|
|
Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-lmin <var>lambda</var></samp>’</dt>
|
|
<dd><p>minimum video lagrange factor (VBR)
|
|
</p></dd>
|
|
<dt> ‘<samp>-lmax <var>lambda</var></samp>’</dt>
|
|
<dd><p>max video lagrange factor (VBR)
|
|
</p></dd>
|
|
<dt> ‘<samp>-mblmin <var>lambda</var></samp>’</dt>
|
|
<dd><p>minimum macroblock quantizer scale (VBR)
|
|
</p></dd>
|
|
<dt> ‘<samp>-mblmax <var>lambda</var></samp>’</dt>
|
|
<dd><p>maximum macroblock quantizer scale (VBR)
|
|
</p>
|
|
<p>These four options (lmin, lmax, mblmin, mblmax) use ’lambda’ units,
|
|
but you may use the QP2LAMBDA constant to easily convert from ’q’ units:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-rc_init_cplx <var>complexity</var></samp>’</dt>
|
|
<dd><p>initial complexity for single pass encoding
|
|
</p></dd>
|
|
<dt> ‘<samp>-b_qfactor <var>factor</var></samp>’</dt>
|
|
<dd><p>qp factor between P- and B-frames
|
|
</p></dd>
|
|
<dt> ‘<samp>-i_qfactor <var>factor</var></samp>’</dt>
|
|
<dd><p>qp factor between P- and I-frames
|
|
</p></dd>
|
|
<dt> ‘<samp>-b_qoffset <var>offset</var></samp>’</dt>
|
|
<dd><p>qp offset between P- and B-frames
|
|
</p></dd>
|
|
<dt> ‘<samp>-i_qoffset <var>offset</var></samp>’</dt>
|
|
<dd><p>qp offset between P- and I-frames
|
|
</p></dd>
|
|
<dt> ‘<samp>-rc_eq <var>equation</var></samp>’</dt>
|
|
<dd><p>Set rate control equation (see section "Expression Evaluation")
|
|
(default = <code>tex^qComp</code>).
|
|
</p>
|
|
<p>When computing the rate control equation expression, besides the
|
|
standard functions defined in the section "Expression Evaluation", the
|
|
following functions are available:
|
|
</p><dl compact="compact">
|
|
<dt> <var>bits2qp(bits)</var></dt>
|
|
<dt> <var>qp2bits(qp)</var></dt>
|
|
</dl>
|
|
|
|
<p>and the following constants are available:
|
|
</p><dl compact="compact">
|
|
<dt> <var>iTex</var></dt>
|
|
<dt> <var>pTex</var></dt>
|
|
<dt> <var>tex</var></dt>
|
|
<dt> <var>mv</var></dt>
|
|
<dt> <var>fCode</var></dt>
|
|
<dt> <var>iCount</var></dt>
|
|
<dt> <var>mcVar</var></dt>
|
|
<dt> <var>var</var></dt>
|
|
<dt> <var>isI</var></dt>
|
|
<dt> <var>isP</var></dt>
|
|
<dt> <var>isB</var></dt>
|
|
<dt> <var>avgQP</var></dt>
|
|
<dt> <var>qComp</var></dt>
|
|
<dt> <var>avgIITex</var></dt>
|
|
<dt> <var>avgPITex</var></dt>
|
|
<dt> <var>avgPPTex</var></dt>
|
|
<dt> <var>avgBPTex</var></dt>
|
|
<dt> <var>avgTex</var></dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-rc_override[:<var>stream_specifier</var>] <var>override</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Rate control override for specific intervals, formatted as "int,int,int"
|
|
list separated with slashes. Two first values are the beginning and
|
|
end frame numbers, last one is quantizer to use if positive, or quality
|
|
factor if negative.
|
|
</p></dd>
|
|
<dt> ‘<samp>-me_method <var>method</var></samp>’</dt>
|
|
<dd><p>Set motion estimation method to <var>method</var>.
|
|
Available methods are (from lowest to best quality):
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>zero</samp>’</dt>
|
|
<dd><p>Try just the (0, 0) vector.
|
|
</p></dd>
|
|
<dt> ‘<samp>phods</samp>’</dt>
|
|
<dt> ‘<samp>log</samp>’</dt>
|
|
<dt> ‘<samp>x1</samp>’</dt>
|
|
<dt> ‘<samp>hex</samp>’</dt>
|
|
<dt> ‘<samp>umh</samp>’</dt>
|
|
<dt> ‘<samp>epzs</samp>’</dt>
|
|
<dd><p>(default method)
|
|
</p></dd>
|
|
<dt> ‘<samp>full</samp>’</dt>
|
|
<dd><p>exhaustive search (slow and marginally better than epzs)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-dct_algo <var>algo</var></samp>’</dt>
|
|
<dd><p>Set DCT algorithm to <var>algo</var>. Available values are:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>FF_DCT_AUTO (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>FF_DCT_FASTINT
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>FF_DCT_INT
|
|
</p></dd>
|
|
<dt> ‘<samp>3</samp>’</dt>
|
|
<dd><p>FF_DCT_MMX
|
|
</p></dd>
|
|
<dt> ‘<samp>4</samp>’</dt>
|
|
<dd><p>FF_DCT_MLIB
|
|
</p></dd>
|
|
<dt> ‘<samp>5</samp>’</dt>
|
|
<dd><p>FF_DCT_ALTIVEC
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-idct_algo <var>algo</var></samp>’</dt>
|
|
<dd><p>Set IDCT algorithm to <var>algo</var>. Available values are:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>FF_IDCT_AUTO (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>FF_IDCT_INT
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>FF_IDCT_SIMPLE
|
|
</p></dd>
|
|
<dt> ‘<samp>3</samp>’</dt>
|
|
<dd><p>FF_IDCT_SIMPLEMMX
|
|
</p></dd>
|
|
<dt> ‘<samp>4</samp>’</dt>
|
|
<dd><p>FF_IDCT_LIBMPEG2MMX
|
|
</p></dd>
|
|
<dt> ‘<samp>5</samp>’</dt>
|
|
<dd><p>FF_IDCT_PS2
|
|
</p></dd>
|
|
<dt> ‘<samp>6</samp>’</dt>
|
|
<dd><p>FF_IDCT_MLIB
|
|
</p></dd>
|
|
<dt> ‘<samp>7</samp>’</dt>
|
|
<dd><p>FF_IDCT_ARM
|
|
</p></dd>
|
|
<dt> ‘<samp>8</samp>’</dt>
|
|
<dd><p>FF_IDCT_ALTIVEC
|
|
</p></dd>
|
|
<dt> ‘<samp>9</samp>’</dt>
|
|
<dd><p>FF_IDCT_SH4
|
|
</p></dd>
|
|
<dt> ‘<samp>10</samp>’</dt>
|
|
<dd><p>FF_IDCT_SIMPLEARM
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-er <var>n</var></samp>’</dt>
|
|
<dd><p>Set error resilience to <var>n</var>.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>FF_ER_CAREFUL (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>FF_ER_COMPLIANT
|
|
</p></dd>
|
|
<dt> ‘<samp>3</samp>’</dt>
|
|
<dd><p>FF_ER_AGGRESSIVE
|
|
</p></dd>
|
|
<dt> ‘<samp>4</samp>’</dt>
|
|
<dd><p>FF_ER_VERY_AGGRESSIVE
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-ec <var>bit_mask</var></samp>’</dt>
|
|
<dd><p>Set error concealment to <var>bit_mask</var>. <var>bit_mask</var> is a bit mask of
|
|
the following values:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>FF_EC_GUESS_MVS (default = enabled)
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>FF_EC_DEBLOCK (default = enabled)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-bf <var>frames</var></samp>’</dt>
|
|
<dd><p>Use ’frames’ B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
|
|
</p></dd>
|
|
<dt> ‘<samp>-mbd <var>mode</var></samp>’</dt>
|
|
<dd><p>macroblock decision
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in ffmpeg).
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>FF_MB_DECISION_RD: rate distortion
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-4mv</samp>’</dt>
|
|
<dd><p>Use four motion vector by macroblock (MPEG-4 only).
|
|
</p></dd>
|
|
<dt> ‘<samp>-part</samp>’</dt>
|
|
<dd><p>Use data partitioning (MPEG-4 only).
|
|
</p></dd>
|
|
<dt> ‘<samp>-bug <var>param</var></samp>’</dt>
|
|
<dd><p>Work around encoder bugs that are not auto-detected.
|
|
</p></dd>
|
|
<dt> ‘<samp>-strict <var>strictness</var></samp>’</dt>
|
|
<dd><p>How strictly to follow the standards.
|
|
</p></dd>
|
|
<dt> ‘<samp>-aic</samp>’</dt>
|
|
<dd><p>Enable Advanced intra coding (h263+).
|
|
</p></dd>
|
|
<dt> ‘<samp>-umv</samp>’</dt>
|
|
<dd><p>Enable Unlimited Motion Vector (h263+)
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-deinterlace</samp>’</dt>
|
|
<dd><p>Deinterlace pictures.
|
|
</p></dd>
|
|
<dt> ‘<samp>-ilme</samp>’</dt>
|
|
<dd><p>Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
|
|
Use this option if your input file is interlaced and you want
|
|
to keep the interlaced format for minimum losses.
|
|
The alternative is to deinterlace the input stream with
|
|
‘<samp>-deinterlace</samp>’, but deinterlacing introduces losses.
|
|
</p></dd>
|
|
<dt> ‘<samp>-psnr</samp>’</dt>
|
|
<dd><p>Calculate PSNR of compressed frames.
|
|
</p></dd>
|
|
<dt> ‘<samp>-vstats</samp>’</dt>
|
|
<dd><p>Dump video coding statistics to ‘<tt>vstats_HHMMSS.log</tt>’.
|
|
</p></dd>
|
|
<dt> ‘<samp>-vstats_file <var>file</var></samp>’</dt>
|
|
<dd><p>Dump video coding statistics to <var>file</var>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-top[:<var>stream_specifier</var>] <var>n</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>top=1/bottom=0/auto=-1 field first
|
|
</p></dd>
|
|
<dt> ‘<samp>-dc <var>precision</var></samp>’</dt>
|
|
<dd><p>Intra_dc_precision.
|
|
</p></dd>
|
|
<dt> ‘<samp>-vtag <var>fourcc/tag</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Force video tag/fourcc. This is an alias for <code>-tag:v</code>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-qphist (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Show QP histogram
|
|
</p></dd>
|
|
<dt> ‘<samp>-vbsf <var>bitstream_filter</var></samp>’</dt>
|
|
<dd><p>Deprecated see -bsf
|
|
</p></dd>
|
|
<dt> ‘<samp>-force_key_frames[:<var>stream_specifier</var>] <var>time</var>[,<var>time</var>...] (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Force key frames at the specified timestamps, more precisely at the first
|
|
frames after each specified time.
|
|
This option can be useful to ensure that a seek point is present at a
|
|
chapter mark or any other designated place in the output file.
|
|
The timestamps must be specified in ascending order.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-copyinkf[:<var>stream_specifier</var>] (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>When doing stream copy, copy also non-key frames found at the
|
|
beginning.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Audio-Options"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Audio-Options">4.7 Audio Options</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-aframes <var>number</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Set the number of audio frames to record. This is an alias for <code>-frames:a</code>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-ar[:<var>stream_specifier</var>] <var>freq</var> (<em>input/output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set the audio sampling frequency. For output streams it is set by
|
|
default to the frequency of the corresponding input stream. For input
|
|
streams this option only makes sense for audio grabbing devices and raw
|
|
demuxers and is mapped to the corresponding demuxer options.
|
|
</p></dd>
|
|
<dt> ‘<samp>-aq <var>q</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
|
|
</p></dd>
|
|
<dt> ‘<samp>-ac[:<var>stream_specifier</var>] <var>channels</var> (<em>input/output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set the number of audio channels. For output streams it is set by
|
|
default to the number of input audio channels. For input streams
|
|
this option only makes sense for audio grabbing devices and raw demuxers
|
|
and is mapped to the corresponding demuxer options.
|
|
</p></dd>
|
|
<dt> ‘<samp>-an (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Disable audio recording.
|
|
</p></dd>
|
|
<dt> ‘<samp>-acodec <var>codec</var> (<em>input/output</em>)</samp>’</dt>
|
|
<dd><p>Set the audio codec. This is an alias for <code>-codec:a</code>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-sample_fmt[:<var>stream_specifier</var>] <var>sample_fmt</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set the audio sample format. Use <code>-sample_fmts</code> to get a list
|
|
of supported sample formats.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Advanced-Audio-options_003a"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Advanced-Audio-options_003a">4.8 Advanced Audio options:</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-atag <var>fourcc/tag</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Force audio tag/fourcc. This is an alias for <code>-tag:a</code>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-audio_service_type <var>type</var></samp>’</dt>
|
|
<dd><p>Set the type of service that the audio stream contains.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>ma</samp>’</dt>
|
|
<dd><p>Main Audio Service (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>ef</samp>’</dt>
|
|
<dd><p>Effects
|
|
</p></dd>
|
|
<dt> ‘<samp>vi</samp>’</dt>
|
|
<dd><p>Visually Impaired
|
|
</p></dd>
|
|
<dt> ‘<samp>hi</samp>’</dt>
|
|
<dd><p>Hearing Impaired
|
|
</p></dd>
|
|
<dt> ‘<samp>di</samp>’</dt>
|
|
<dd><p>Dialogue
|
|
</p></dd>
|
|
<dt> ‘<samp>co</samp>’</dt>
|
|
<dd><p>Commentary
|
|
</p></dd>
|
|
<dt> ‘<samp>em</samp>’</dt>
|
|
<dd><p>Emergency
|
|
</p></dd>
|
|
<dt> ‘<samp>vo</samp>’</dt>
|
|
<dd><p>Voice Over
|
|
</p></dd>
|
|
<dt> ‘<samp>ka</samp>’</dt>
|
|
<dd><p>Karaoke
|
|
</p></dd>
|
|
</dl>
|
|
</dd>
|
|
<dt> ‘<samp>-absf <var>bitstream_filter</var></samp>’</dt>
|
|
<dd><p>Deprecated, see -bsf
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Subtitle-options_003a"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Subtitle-options_003a">4.9 Subtitle options:</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-slang <var>code</var></samp>’</dt>
|
|
<dd><p>Set the ISO 639 language code (3 letters) of the current subtitle stream.
|
|
</p></dd>
|
|
<dt> ‘<samp>-scodec <var>codec</var> (<em>input/output</em>)</samp>’</dt>
|
|
<dd><p>Set the subtitle codec. This is an alias for <code>-codec:s</code>.
|
|
</p></dd>
|
|
<dt> ‘<samp>-sn (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Disable subtitle recording.
|
|
</p></dd>
|
|
<dt> ‘<samp>-sbsf <var>bitstream_filter</var></samp>’</dt>
|
|
<dd><p>Deprecated, see -bsf
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Audio_002fVideo-grab-options"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Audio_002fVideo-grab-options">4.10 Audio/Video grab options</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-isync (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Synchronize read on input.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Advanced-options"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Advanced-options">4.11 Advanced options</a></h2>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-map [-]<var>input_file_id</var>[:<var>stream_specifier</var>][,<var>sync_file_id</var>[:<var>stream_specifier</var>]] (<em>output</em>)</samp>’</dt>
|
|
<dd>
|
|
<p>Designate one or more input streams as a source for the output file. Each input
|
|
stream is identified by the input file index <var>input_file_id</var> and
|
|
the input stream index <var>input_stream_id</var> within the input
|
|
file. Both indices start at 0. If specified,
|
|
<var>sync_file_id</var>:<var>stream_specifier</var> sets which input stream
|
|
is used as a presentation sync reference.
|
|
</p>
|
|
<p>The first <code>-map</code> option on the command line specifies the
|
|
source for output stream 0, the second <code>-map</code> option specifies
|
|
the source for output stream 1, etc.
|
|
</p>
|
|
<p>A <code>-</code> character before the stream identifier creates a "negative" mapping.
|
|
It disables matching streams from already created mappings.
|
|
</p>
|
|
<p>For example, to map ALL streams from the first input file to output
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map 0 output
|
|
</pre></td></tr></table>
|
|
|
|
<p>For example, if you have two audio streams in the first input file,
|
|
these streams are identified by "0:0" and "0:1". You can use
|
|
<code>-map</code> to select which streams to place in an output file. For
|
|
example:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map 0:1 out.wav
|
|
</pre></td></tr></table>
|
|
<p>will map the input stream in ‘<tt>INPUT</tt>’ identified by "0:1" to
|
|
the (single) output stream in ‘<tt>out.wav</tt>’.
|
|
</p>
|
|
<p>For example, to select the stream with index 2 from input file
|
|
‘<tt>a.mov</tt>’ (specified by the identifier "0:2"), and stream with
|
|
index 6 from input ‘<tt>b.mov</tt>’ (specified by the identifier "1:6"),
|
|
and copy them to the output file ‘<tt>out.mov</tt>’:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
|
|
</pre></td></tr></table>
|
|
|
|
<p>To select all video and the third audio stream from an input file:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
|
|
</pre></td></tr></table>
|
|
|
|
<p>To map all the streams except the second audio, use negative mappings
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that using this option disables the default mappings for this output file.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-map_channel [<var>input_file_id</var>.<var>stream_specifier</var>.<var>channel_id</var>|-1][:<var>output_file_id</var>.<var>stream_specifier</var>]</samp>’</dt>
|
|
<dd><p>Map an audio channel from a given input to an output. If
|
|
<var>output_file_id</var>.<var>stream_specifier</var> are not set, the audio channel will
|
|
be mapped on all the audio streams.
|
|
</p>
|
|
<p>Using "-1" instead of
|
|
<var>input_file_id</var>.<var>stream_specifier</var>.<var>channel_id</var> will map a muted
|
|
channel.
|
|
</p>
|
|
<p>For example, assuming <var>INPUT</var> is a stereo audio file, you can switch the
|
|
two audio channels with the following command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
|
|
</pre></td></tr></table>
|
|
|
|
<p>If you want to mute the first channel and keep the second:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
|
|
</pre></td></tr></table>
|
|
|
|
<p>The order of the "-map_channel" option specifies the order of the channels in
|
|
the output stream. The output channel layout is guessed from the number of
|
|
channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
|
|
in combination of "-map_channel" makes the channel gain levels to be updated if
|
|
channel layouts don’t match (for instance two "-map_channel" options and "-ac
|
|
6").
|
|
</p>
|
|
<p>You can also extract each channel of an <var>INPUT</var> to specific outputs; the
|
|
following command extract each channel of the audio stream (file 0, stream 0)
|
|
to the respective <var>OUTPUT_CH0</var> and <var>OUTPUT_CH1</var>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
|
|
</pre></td></tr></table>
|
|
|
|
<p>The following example split the channels of a stereo input into streams:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that currently each output stream can only contain channels from a single
|
|
input stream; you can’t for example use "-map_channel" to pick multiple input
|
|
audio channels contained in different streams (from the same or different files)
|
|
and merge them into a single output stream. It is therefore not currently
|
|
possible, for example, to turn two separate mono streams into a single stereo
|
|
stream. However spliting a stereo stream into two single channel mono streams
|
|
is possible.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-map_metadata[:<var>metadata_spec_out</var>] <var>infile</var>[:<var>metadata_spec_in</var>] (<em>output,per-metadata</em>)</samp>’</dt>
|
|
<dd><p>Set metadata information of the next output file from <var>infile</var>. Note that
|
|
those are file indices (zero-based), not filenames.
|
|
Optional <var>metadata_spec_in/out</var> parameters specify, which metadata to copy.
|
|
A metadata specifier can have the following forms:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp><var>g</var></samp>’</dt>
|
|
<dd><p>global metadata, i.e. metadata that applies to the whole file
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp><var>s</var>[:<var>stream_spec</var>]</samp>’</dt>
|
|
<dd><p>per-stream metadata. <var>stream_spec</var> is a stream specifier as described
|
|
in the <a href="#Stream-specifiers">Stream specifiers</a> chapter. In an input metadata specifier, the first
|
|
matching stream is copied from. In an output metadata specifier, all matching
|
|
streams are copied to.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp><var>c</var>:<var>chapter_index</var></samp>’</dt>
|
|
<dd><p>per-chapter metadata. <var>chapter_index</var> is the zero-based chapter index.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp><var>p</var>:<var>program_index</var></samp>’</dt>
|
|
<dd><p>per-program metadata. <var>program_index</var> is the zero-based program index.
|
|
</p></dd>
|
|
</dl>
|
|
<p>If metadata specifier is omitted, it defaults to global.
|
|
</p>
|
|
<p>By default, global metadata is copied from the first input file,
|
|
per-stream and per-chapter metadata is copied along with streams/chapters. These
|
|
default mappings are disabled by creating any mapping of the relevant type. A negative
|
|
file index can be used to create a dummy mapping that just disables automatic copying.
|
|
</p>
|
|
<p>For example to copy metadata from the first stream of the input file to global metadata
|
|
of the output file:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
|
|
</pre></td></tr></table>
|
|
|
|
<p>To do the reverse, i.e. copy global metadata to all audio streams:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
|
|
</pre></td></tr></table>
|
|
<p>Note that simple <code>0</code> would work as well in this example, since global
|
|
metadata is assumed by default.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-map_chapters <var>input_file_index</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Copy chapters from input file with index <var>input_file_index</var> to the next
|
|
output file. If no chapter mapping is specified, then chapters are copied from
|
|
the first input file with at least one chapter. Use a negative file index to
|
|
disable any chapter copying.
|
|
</p></dd>
|
|
<dt> ‘<samp>-debug <var>category</var></samp>’</dt>
|
|
<dd><p>Print specific debug info.
|
|
<var>category</var> is a number or a string containing one of the following values:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>bitstream</samp>’</dt>
|
|
<dt> ‘<samp>buffers</samp>’</dt>
|
|
<dd><p>picture buffer allocations
|
|
</p></dd>
|
|
<dt> ‘<samp>bugs</samp>’</dt>
|
|
<dt> ‘<samp>dct_coeff</samp>’</dt>
|
|
<dt> ‘<samp>er</samp>’</dt>
|
|
<dd><p>error recognition
|
|
</p></dd>
|
|
<dt> ‘<samp>mb_type</samp>’</dt>
|
|
<dd><p>macroblock (MB) type
|
|
</p></dd>
|
|
<dt> ‘<samp>mmco</samp>’</dt>
|
|
<dd><p>memory management control operations (H.264)
|
|
</p></dd>
|
|
<dt> ‘<samp>mv</samp>’</dt>
|
|
<dd><p>motion vector
|
|
</p></dd>
|
|
<dt> ‘<samp>pict</samp>’</dt>
|
|
<dd><p>picture info
|
|
</p></dd>
|
|
<dt> ‘<samp>pts</samp>’</dt>
|
|
<dt> ‘<samp>qp</samp>’</dt>
|
|
<dd><p>per-block quantization parameter (QP)
|
|
</p></dd>
|
|
<dt> ‘<samp>rc</samp>’</dt>
|
|
<dd><p>rate control
|
|
</p></dd>
|
|
<dt> ‘<samp>skip</samp>’</dt>
|
|
<dt> ‘<samp>startcode</samp>’</dt>
|
|
<dt> ‘<samp>thread_ops</samp>’</dt>
|
|
<dd><p>threading operations
|
|
</p></dd>
|
|
<dt> ‘<samp>vis_mb_type</samp>’</dt>
|
|
<dd><p>visualize block types
|
|
</p></dd>
|
|
<dt> ‘<samp>vis_qp</samp>’</dt>
|
|
<dd><p>visualize quantization parameter (QP), lower QP are tinted greener
|
|
</p></dd>
|
|
</dl>
|
|
</dd>
|
|
<dt> ‘<samp>-benchmark (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Show benchmarking information at the end of an encode.
|
|
Shows CPU time used and maximum memory consumption.
|
|
Maximum memory consumption is not supported on all systems,
|
|
it will usually display as 0 if not supported.
|
|
</p></dd>
|
|
<dt> ‘<samp>-timelimit <var>duration</var> (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Exit after ffmpeg has been running for <var>duration</var> seconds.
|
|
</p></dd>
|
|
<dt> ‘<samp>-dump (<em>global</em>)</samp>’</dt>
|
|
<dd><p>Dump each input packet to stderr.
|
|
</p></dd>
|
|
<dt> ‘<samp>-hex (<em>global</em>)</samp>’</dt>
|
|
<dd><p>When dumping packets, also dump the payload.
|
|
</p></dd>
|
|
<dt> ‘<samp>-ps <var>size</var></samp>’</dt>
|
|
<dd><p>Set RTP payload size in bytes.
|
|
</p></dd>
|
|
<dt> ‘<samp>-re (<em>input</em>)</samp>’</dt>
|
|
<dd><p>Read input at native frame rate. Mainly used to simulate a grab device.
|
|
</p></dd>
|
|
<dt> ‘<samp>-loop_input</samp>’</dt>
|
|
<dd><p>Loop over the input stream. Currently it works only for image
|
|
streams. This option is used for automatic FFserver testing.
|
|
This option is deprecated, use -loop 1.
|
|
</p></dd>
|
|
<dt> ‘<samp>-loop_output <var>number_of_times</var></samp>’</dt>
|
|
<dd><p>Repeatedly loop output for formats that support looping such as animated GIF
|
|
(0 will loop the output infinitely).
|
|
This option is deprecated, use -loop.
|
|
</p></dd>
|
|
<dt> ‘<samp>-threads <var>count</var></samp>’</dt>
|
|
<dd><p>Thread count.
|
|
</p></dd>
|
|
<dt> ‘<samp>-vsync <var>parameter</var></samp>’</dt>
|
|
<dd><p>Video sync method.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>0, passthrough</samp>’</dt>
|
|
<dd><p>Each frame is passed with its timestamp from the demuxer to the muxer.
|
|
</p></dd>
|
|
<dt> ‘<samp>1, cfr</samp>’</dt>
|
|
<dd><p>Frames will be duplicated and dropped to achieve exactly the requested
|
|
constant framerate.
|
|
</p></dd>
|
|
<dt> ‘<samp>2, vfr</samp>’</dt>
|
|
<dd><p>Frames are passed through with their timestamp or dropped so as to
|
|
prevent 2 frames from having the same timestamp.
|
|
</p></dd>
|
|
<dt> ‘<samp>-1, auto</samp>’</dt>
|
|
<dd><p>Chooses between 1 and 2 depending on muxer capabilities. This is the
|
|
default method.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>With -map you can select from which stream the timestamps should be
|
|
taken. You can leave either video or audio unchanged and sync the
|
|
remaining stream(s) to the unchanged one.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-async <var>samples_per_second</var></samp>’</dt>
|
|
<dd><p>Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
|
|
the parameter is the maximum samples per second by which the audio is changed.
|
|
-async 1 is a special case where only the start of the audio stream is corrected
|
|
without any later correction.
|
|
</p></dd>
|
|
<dt> ‘<samp>-copyts</samp>’</dt>
|
|
<dd><p>Copy timestamps from input to output.
|
|
</p></dd>
|
|
<dt> ‘<samp>-copytb</samp>’</dt>
|
|
<dd><p>Copy input stream time base from input to output when stream copying.
|
|
</p></dd>
|
|
<dt> ‘<samp>-shortest</samp>’</dt>
|
|
<dd><p>Finish encoding when the shortest input stream ends.
|
|
</p></dd>
|
|
<dt> ‘<samp>-dts_delta_threshold</samp>’</dt>
|
|
<dd><p>Timestamp discontinuity delta threshold.
|
|
</p></dd>
|
|
<dt> ‘<samp>-muxdelay <var>seconds</var> (<em>input</em>)</samp>’</dt>
|
|
<dd><p>Set the maximum demux-decode delay.
|
|
</p></dd>
|
|
<dt> ‘<samp>-muxpreload <var>seconds</var> (<em>input</em>)</samp>’</dt>
|
|
<dd><p>Set the initial demux-decode delay.
|
|
</p></dd>
|
|
<dt> ‘<samp>-streamid <var>output-stream-index</var>:<var>new-value</var> (<em>output</em>)</samp>’</dt>
|
|
<dd><p>Assign a new stream-id value to an output stream. This option should be
|
|
specified prior to the output filename to which it applies.
|
|
For the situation where multiple output files exist, a streamid
|
|
may be reassigned to a different value.
|
|
</p>
|
|
<p>For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
|
|
an output mpegts file:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-bsf[:<var>stream_specifier</var>] <var>bitstream_filters</var> (<em>output,per-stream</em>)</samp>’</dt>
|
|
<dd><p>Set bitstream filters for matching streams. <var>bistream_filters</var> is
|
|
a comma-separated list of bitstream filters. Use the <code>-bsfs</code> option
|
|
to get the list of bitstream filters.
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
|
|
</pre></td></tr></table>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-tag[:<var>stream_specifier</var>] <var>codec_tag</var> (<em>per-stream</em>)</samp>’</dt>
|
|
<dd><p>Force a tag/fourcc for matching streams.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-timecode <var>hh</var>:<var>mm</var>:<var>ss</var>SEP<var>ff</var></samp>’</dt>
|
|
<dd><p>Specify Timecode for writing. <var>SEP</var> is ’:’ for non drop timecode and ’;’
|
|
(or ’.’) for drop.
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
|
|
</pre></td></tr></table>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Preset-files"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Preset-files">4.12 Preset files</a></h2>
|
|
<p>A preset file contains a sequence of <var>option</var>=<var>value</var> pairs,
|
|
one for each line, specifying a sequence of options which would be
|
|
awkward to specify on the command line. Lines starting with the hash
|
|
(’#’) character are ignored and are used to provide comments. Check
|
|
the ‘<tt>presets</tt>’ directory in the FFmpeg source tree for examples.
|
|
</p>
|
|
<p>Preset files are specified with the <code>vpre</code>, <code>apre</code>,
|
|
<code>spre</code>, and <code>fpre</code> options. The <code>fpre</code> option takes the
|
|
filename of the preset instead of a preset name as input and can be
|
|
used for any kind of codec. For the <code>vpre</code>, <code>apre</code>, and
|
|
<code>spre</code> options, the options specified in a preset file are
|
|
applied to the currently selected codec of the same type as the preset
|
|
option.
|
|
</p>
|
|
<p>The argument passed to the <code>vpre</code>, <code>apre</code>, and <code>spre</code>
|
|
preset options identifies the preset file to use according to the
|
|
following rules:
|
|
</p>
|
|
<p>First ffmpeg searches for a file named <var>arg</var>.ffpreset in the
|
|
directories ‘<tt>$FFMPEG_DATADIR</tt>’ (if set), and ‘<tt>$HOME/.ffmpeg</tt>’, and in
|
|
the datadir defined at configuration time (usually ‘<tt>PREFIX/share/ffmpeg</tt>’)
|
|
or in a ‘<tt>ffpresets</tt>’ folder along the executable on win32,
|
|
in that order. For example, if the argument is <code>libx264-max</code>, it will
|
|
search for the file ‘<tt>libx264-max.ffpreset</tt>’.
|
|
</p>
|
|
<p>If no such file is found, then ffmpeg will search for a file named
|
|
<var>codec_name</var>-<var>arg</var>.ffpreset in the above-mentioned
|
|
directories, where <var>codec_name</var> is the name of the codec to which
|
|
the preset file options will be applied. For example, if you select
|
|
the video codec with <code>-vcodec libx264</code> and use <code>-vpre max</code>,
|
|
then it will search for the file ‘<tt>libx264-max.ffpreset</tt>’.
|
|
</p>
|
|
<a name="Tips"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Tips">5. Tips</a></h1>
|
|
|
|
<ul>
|
|
<li>
|
|
For streaming at very low bitrate application, use a low frame rate
|
|
and a small GOP size. This is especially true for RealVideo where
|
|
the Linux player does not seem to be very fast, so it can miss
|
|
frames. An example is:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
The parameter ’q’ which is displayed while encoding is the current
|
|
quantizer. The value 1 indicates that a very good quality could
|
|
be achieved. The value 31 indicates the worst quality. If q=31 appears
|
|
too often, it means that the encoder cannot compress enough to meet
|
|
your bitrate. You must either increase the bitrate, decrease the
|
|
frame rate or decrease the frame size.
|
|
|
|
</li><li>
|
|
If your computer is not fast enough, you can speed up the
|
|
compression at the expense of the compression ratio. You can use
|
|
’-me zero’ to speed up motion estimation, and ’-intra’ to disable
|
|
motion estimation completely (you have only I-frames, which means it
|
|
is about as good as JPEG compression).
|
|
|
|
</li><li>
|
|
To have very low audio bitrates, reduce the sampling frequency
|
|
(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
|
|
|
|
</li><li>
|
|
To have a constant quality (but a variable bitrate), use the option
|
|
’-qscale n’ when ’n’ is between 1 (excellent quality) and 31 (worst
|
|
quality).
|
|
|
|
</li></ul>
|
|
|
|
<a name="Examples"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Examples">6. Examples</a></h1>
|
|
|
|
<a name="Preset-files-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Preset-files-1">6.1 Preset files</a></h2>
|
|
|
|
<p>A preset file contains a sequence of <var>option=value</var> pairs, one for
|
|
each line, specifying a sequence of options which can be specified also on
|
|
the command line. Lines starting with the hash (’#’) character are ignored and
|
|
are used to provide comments. Empty lines are also ignored. Check the
|
|
‘<tt>presets</tt>’ directory in the FFmpeg source tree for examples.
|
|
</p>
|
|
<p>Preset files are specified with the <code>pre</code> option, this option takes a
|
|
preset name as input. FFmpeg searches for a file named <var>preset_name</var>.avpreset in
|
|
the directories ‘<tt>$AVCONV_DATADIR</tt>’ (if set), and ‘<tt>$HOME/.ffmpeg</tt>’, and in
|
|
the data directory defined at configuration time (usually ‘<tt>$PREFIX/share/ffmpeg</tt>’)
|
|
in that order. For example, if the argument is <code>libx264-max</code>, it will
|
|
search for the file ‘<tt>libx264-max.avpreset</tt>’.
|
|
</p>
|
|
<a name="Video-and-Audio-grabbing"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Video-and-Audio-grabbing">6.2 Video and Audio grabbing</a></h2>
|
|
|
|
<p>If you specify the input format and device then ffmpeg can grab video
|
|
and audio directly.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Or with an ALSA audio source (mono input, card id 1) instead of OSS:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that you must activate the right video source and channel before
|
|
launching ffmpeg with any TV viewer such as
|
|
<a href="http://linux.bytesex.org/xawtv/">xawtv</a> by Gerd Knorr. You also
|
|
have to set the audio recording levels correctly with a
|
|
standard mixer.
|
|
</p>
|
|
<a name="X11-grabbing"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-X11-grabbing">6.3 X11 grabbing</a></h2>
|
|
|
|
<p>Grab the X11 display with ffmpeg via
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>0.0 is display.screen number of your X11 server, same as
|
|
the DISPLAY environment variable.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>0.0 is display.screen number of your X11 server, same as the DISPLAY environment
|
|
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
|
|
</p>
|
|
<a name="Video-and-Audio-file-format-conversion"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Video-and-Audio-file-format-conversion">6.4 Video and Audio file format conversion</a></h2>
|
|
|
|
<p>Any supported file format and protocol can serve as input to ffmpeg:
|
|
</p>
|
|
<p>Examples:
|
|
</p><ul>
|
|
<li>
|
|
You can use YUV files as input:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>It will use the files:
|
|
</p><table><tr><td> </td><td><pre class="example">/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
|
|
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
|
|
</pre></td></tr></table>
|
|
|
|
<p>The Y files use twice the resolution of the U and V files. They are
|
|
raw files, without header. They can be generated by all decent video
|
|
decoders. You must specify the size of the image with the ‘<samp>-s</samp>’ option
|
|
if ffmpeg cannot guess it.
|
|
</p>
|
|
</li><li>
|
|
You can input from a raw YUV420P file:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i /tmp/test.yuv /tmp/out.avi
|
|
</pre></td></tr></table>
|
|
|
|
<p>test.yuv is a file containing raw YUV planar data. Each frame is composed
|
|
of the Y plane followed by the U and V planes at half vertical and
|
|
horizontal resolution.
|
|
</p>
|
|
</li><li>
|
|
You can output to a raw YUV420P file:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i mydivx.avi hugefile.yuv
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
You can set several input files and output files:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Converts the audio file a.wav and the raw YUV video file a.yuv
|
|
to MPEG file a.mpg.
|
|
</p>
|
|
</li><li>
|
|
You can also do audio and video conversions at the same time:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
|
|
</pre></td></tr></table>
|
|
|
|
<p>Converts a.wav to MPEG audio at 22050 Hz sample rate.
|
|
</p>
|
|
</li><li>
|
|
You can encode to several formats at the same time and define a
|
|
mapping from input stream to output streams:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
|
|
</pre></td></tr></table>
|
|
|
|
<p>Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. ’-map
|
|
file:index’ specifies which input stream is used for each output
|
|
stream, in the order of the definition of output streams.
|
|
</p>
|
|
</li><li>
|
|
You can transcode decrypted VOBs:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
|
|
</pre></td></tr></table>
|
|
|
|
<p>This is a typical DVD ripping example; the input is a VOB file, the
|
|
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
|
|
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
|
|
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
|
|
input video. Furthermore, the audio stream is MP3-encoded so you need
|
|
to enable LAME support by passing <code>--enable-libmp3lame</code> to configure.
|
|
The mapping is particularly useful for DVD transcoding
|
|
to get the desired audio language.
|
|
</p>
|
|
<p>NOTE: To see the supported input formats, use <code>ffmpeg -formats</code>.
|
|
</p>
|
|
</li><li>
|
|
You can extract images from a video, or create a video from many images:
|
|
|
|
<p>For extracting images from a video:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
|
|
</pre></td></tr></table>
|
|
|
|
<p>This will extract one video frame per second from the video and will
|
|
output them in files named ‘<tt>foo-001.jpeg</tt>’, ‘<tt>foo-002.jpeg</tt>’,
|
|
etc. Images will be rescaled to fit the new WxH values.
|
|
</p>
|
|
<p>If you want to extract just a limited number of frames, you can use the
|
|
above command in combination with the -vframes or -t option, or in
|
|
combination with -ss to start extracting from a certain point in time.
|
|
</p>
|
|
<p>For creating a video from many images:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
|
|
</pre></td></tr></table>
|
|
|
|
<p>The syntax <code>foo-%03d.jpeg</code> specifies to use a decimal number
|
|
composed of three digits padded with zeroes to express the sequence
|
|
number. It is the same syntax supported by the C printf function, but
|
|
only formats accepting a normal integer are suitable.
|
|
</p>
|
|
</li><li>
|
|
You can put many streams of the same type in the output:
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
|
|
</pre></td></tr></table>
|
|
|
|
<p>The resulting output file ‘<tt>test12.avi</tt>’ will contain first four streams from
|
|
the input file in reverse order.
|
|
</p>
|
|
</li></ul>
|
|
|
|
<a name="Expression-Evaluation"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Expression-Evaluation">7. Expression Evaluation</a></h1>
|
|
|
|
<p>When evaluating an arithmetic expression, FFmpeg uses an internal
|
|
formula evaluator, implemented through the ‘<tt>libavutil/eval.h</tt>’
|
|
interface.
|
|
</p>
|
|
<p>An expression may contain unary, binary operators, constants, and
|
|
functions.
|
|
</p>
|
|
<p>Two expressions <var>expr1</var> and <var>expr2</var> can be combined to form
|
|
another expression "<var>expr1</var>;<var>expr2</var>".
|
|
<var>expr1</var> and <var>expr2</var> are evaluated in turn, and the new
|
|
expression evaluates to the value of <var>expr2</var>.
|
|
</p>
|
|
<p>The following binary operators are available: <code>+</code>, <code>-</code>,
|
|
<code>*</code>, <code>/</code>, <code>^</code>.
|
|
</p>
|
|
<p>The following unary operators are available: <code>+</code>, <code>-</code>.
|
|
</p>
|
|
<p>The following functions are available:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>sinh(x)</samp>’</dt>
|
|
<dt> ‘<samp>cosh(x)</samp>’</dt>
|
|
<dt> ‘<samp>tanh(x)</samp>’</dt>
|
|
<dt> ‘<samp>sin(x)</samp>’</dt>
|
|
<dt> ‘<samp>cos(x)</samp>’</dt>
|
|
<dt> ‘<samp>tan(x)</samp>’</dt>
|
|
<dt> ‘<samp>atan(x)</samp>’</dt>
|
|
<dt> ‘<samp>asin(x)</samp>’</dt>
|
|
<dt> ‘<samp>acos(x)</samp>’</dt>
|
|
<dt> ‘<samp>exp(x)</samp>’</dt>
|
|
<dt> ‘<samp>log(x)</samp>’</dt>
|
|
<dt> ‘<samp>abs(x)</samp>’</dt>
|
|
<dt> ‘<samp>squish(x)</samp>’</dt>
|
|
<dt> ‘<samp>gauss(x)</samp>’</dt>
|
|
<dt> ‘<samp>isnan(x)</samp>’</dt>
|
|
<dd><p>Return 1.0 if <var>x</var> is NAN, 0.0 otherwise.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>mod(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>max(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>min(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>eq(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>gte(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>gt(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>lte(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>lt(x, y)</samp>’</dt>
|
|
<dt> ‘<samp>st(var, expr)</samp>’</dt>
|
|
<dd><p>Allow to store the value of the expression <var>expr</var> in an internal
|
|
variable. <var>var</var> specifies the number of the variable where to
|
|
store the value, and it is a value ranging from 0 to 9. The function
|
|
returns the value stored in the internal variable.
|
|
Note, Variables are currently not shared between expressions.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ld(var)</samp>’</dt>
|
|
<dd><p>Allow to load the value of the internal variable with number
|
|
<var>var</var>, which was previously stored with st(<var>var</var>, <var>expr</var>).
|
|
The function returns the loaded value.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>while(cond, expr)</samp>’</dt>
|
|
<dd><p>Evaluate expression <var>expr</var> while the expression <var>cond</var> is
|
|
non-zero, and returns the value of the last <var>expr</var> evaluation, or
|
|
NAN if <var>cond</var> was always false.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ceil(expr)</samp>’</dt>
|
|
<dd><p>Round the value of expression <var>expr</var> upwards to the nearest
|
|
integer. For example, "ceil(1.5)" is "2.0".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>floor(expr)</samp>’</dt>
|
|
<dd><p>Round the value of expression <var>expr</var> downwards to the nearest
|
|
integer. For example, "floor(-1.5)" is "-2.0".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>trunc(expr)</samp>’</dt>
|
|
<dd><p>Round the value of expression <var>expr</var> towards zero to the nearest
|
|
integer. For example, "trunc(-1.5)" is "-1.0".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sqrt(expr)</samp>’</dt>
|
|
<dd><p>Compute the square root of <var>expr</var>. This is equivalent to
|
|
"(<var>expr</var>)^.5".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>not(expr)</samp>’</dt>
|
|
<dd><p>Return 1.0 if <var>expr</var> is zero, 0.0 otherwise.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pow(x, y)</samp>’</dt>
|
|
<dd><p>Compute the power of <var>x</var> elevated <var>y</var>, it is equivalent to
|
|
"(<var>x</var>)^(<var>y</var>)".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>random(x)</samp>’</dt>
|
|
<dd><p>Return a pseudo random value between 0.0 and 1.0. <var>x</var> is the index of the
|
|
internal variable which will be used to save the seed/state.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>hypot(x, y)</samp>’</dt>
|
|
<dd><p>This function is similar to the C function with the same name; it returns
|
|
"sqrt(<var>x</var>*<var>x</var> + <var>y</var>*<var>y</var>)", the length of the hypotenuse of a
|
|
right triangle with sides of length <var>x</var> and <var>y</var>, or the distance of the
|
|
point (<var>x</var>, <var>y</var>) from the origin.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>gcd(x, y)</samp>’</dt>
|
|
<dd><p>Return the greatest common divisor of <var>x</var> and <var>y</var>. If both <var>x</var> and
|
|
<var>y</var> are 0 or either or both are less than zero then behavior is undefined.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>if(x, y)</samp>’</dt>
|
|
<dd><p>Evaluate <var>x</var>, and if the result is non-zero return the result of
|
|
the evaluation of <var>y</var>, return 0 otherwise.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ifnot(x, y)</samp>’</dt>
|
|
<dd><p>Evaluate <var>x</var>, and if the result is zero return the result of the
|
|
evaluation of <var>y</var>, return 0 otherwise.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The following constants are available:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>PI</samp>’</dt>
|
|
<dd><p>area of the unit disc, approximately 3.14
|
|
</p></dd>
|
|
<dt> ‘<samp>E</samp>’</dt>
|
|
<dd><p>exp(1) (Euler’s number), approximately 2.718
|
|
</p></dd>
|
|
<dt> ‘<samp>PHI</samp>’</dt>
|
|
<dd><p>golden ratio (1+sqrt(5))/2, approximately 1.618
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Assuming that an expression is considered "true" if it has a non-zero
|
|
value, note that:
|
|
</p>
|
|
<p><code>*</code> works like AND
|
|
</p>
|
|
<p><code>+</code> works like OR
|
|
</p>
|
|
<p>and the construct:
|
|
</p><table><tr><td> </td><td><pre class="example">if A then B else C
|
|
</pre></td></tr></table>
|
|
<p>is equivalent to
|
|
</p><table><tr><td> </td><td><pre class="example">if(A,B) + ifnot(A,C)
|
|
</pre></td></tr></table>
|
|
|
|
<p>In your C code, you can extend the list of unary and binary functions,
|
|
and define recognized constants, so that they are available for your
|
|
expressions.
|
|
</p>
|
|
<p>The evaluator also recognizes the International System number
|
|
postfixes. If ’i’ is appended after the postfix, powers of 2 are used
|
|
instead of powers of 10. The ’B’ postfix multiplies the value for 8,
|
|
and can be appended after another postfix or used alone. This allows
|
|
using for example ’KB’, ’MiB’, ’G’ and ’B’ as postfix.
|
|
</p>
|
|
<p>Follows the list of available International System postfixes, with
|
|
indication of the corresponding powers of 10 and of 2.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>y</samp>’</dt>
|
|
<dd><p>-24 / -80
|
|
</p></dd>
|
|
<dt> ‘<samp>z</samp>’</dt>
|
|
<dd><p>-21 / -70
|
|
</p></dd>
|
|
<dt> ‘<samp>a</samp>’</dt>
|
|
<dd><p>-18 / -60
|
|
</p></dd>
|
|
<dt> ‘<samp>f</samp>’</dt>
|
|
<dd><p>-15 / -50
|
|
</p></dd>
|
|
<dt> ‘<samp>p</samp>’</dt>
|
|
<dd><p>-12 / -40
|
|
</p></dd>
|
|
<dt> ‘<samp>n</samp>’</dt>
|
|
<dd><p>-9 / -30
|
|
</p></dd>
|
|
<dt> ‘<samp>u</samp>’</dt>
|
|
<dd><p>-6 / -20
|
|
</p></dd>
|
|
<dt> ‘<samp>m</samp>’</dt>
|
|
<dd><p>-3 / -10
|
|
</p></dd>
|
|
<dt> ‘<samp>c</samp>’</dt>
|
|
<dd><p>-2
|
|
</p></dd>
|
|
<dt> ‘<samp>d</samp>’</dt>
|
|
<dd><p>-1
|
|
</p></dd>
|
|
<dt> ‘<samp>h</samp>’</dt>
|
|
<dd><p>2
|
|
</p></dd>
|
|
<dt> ‘<samp>k</samp>’</dt>
|
|
<dd><p>3 / 10
|
|
</p></dd>
|
|
<dt> ‘<samp>K</samp>’</dt>
|
|
<dd><p>3 / 10
|
|
</p></dd>
|
|
<dt> ‘<samp>M</samp>’</dt>
|
|
<dd><p>6 / 20
|
|
</p></dd>
|
|
<dt> ‘<samp>G</samp>’</dt>
|
|
<dd><p>9 / 30
|
|
</p></dd>
|
|
<dt> ‘<samp>T</samp>’</dt>
|
|
<dd><p>12 / 40
|
|
</p></dd>
|
|
<dt> ‘<samp>P</samp>’</dt>
|
|
<dd><p>15 / 40
|
|
</p></dd>
|
|
<dt> ‘<samp>E</samp>’</dt>
|
|
<dd><p>18 / 50
|
|
</p></dd>
|
|
<dt> ‘<samp>Z</samp>’</dt>
|
|
<dd><p>21 / 60
|
|
</p></dd>
|
|
<dt> ‘<samp>Y</samp>’</dt>
|
|
<dd><p>24 / 70
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Decoders"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Decoders">8. Decoders</a></h1>
|
|
|
|
<p>Decoders are configured elements in FFmpeg which allow the decoding of
|
|
multimedia streams.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported native decoders
|
|
are enabled by default. Decoders requiring an external library must be enabled
|
|
manually via the corresponding <code>--enable-lib</code> option. You can list all
|
|
available decoders using the configure option <code>--list-decoders</code>.
|
|
</p>
|
|
<p>You can disable all the decoders with the configure option
|
|
<code>--disable-decoders</code> and selectively enable / disable single decoders
|
|
with the options <code>--enable-decoder=<var>DECODER</var></code> /
|
|
<code>--disable-decoder=<var>DECODER</var></code>.
|
|
</p>
|
|
<p>The option <code>-codecs</code> of the ff* tools will display the list of
|
|
enabled decoders.
|
|
</p>
|
|
|
|
<a name="Video-Decoders"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Video-Decoders">9. Video Decoders</a></h1>
|
|
|
|
<p>A description of some of the currently available video decoders
|
|
follows.
|
|
</p>
|
|
<a name="rawvideo"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-rawvideo">9.1 rawvideo</a></h2>
|
|
|
|
<p>Raw video decoder.
|
|
</p>
|
|
<p>This decoder decodes rawvideo streams.
|
|
</p>
|
|
<a name="Options-1"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Options-1">9.1.1 Options</a></h3>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>top <var>top_field_first</var></samp>’</dt>
|
|
<dd><p>Specify the assumed field type of the input video.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>-1</samp>’</dt>
|
|
<dd><p>the video is assumed to be progressive (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>bottom-field-first is assumed
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>top-field-first is assumed
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
|
|
<a name="Audio-Decoders"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Audio-Decoders">10. Audio Decoders</a></h1>
|
|
|
|
<a name="ffwavesynth"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-ffwavesynth">10.1 ffwavesynth</a></h2>
|
|
|
|
<p>Internal wave synthetizer.
|
|
</p>
|
|
<p>This decoder generates wave patterns according to predefined sequences. Its
|
|
use is purely internal and the format of the data it accepts is not publicly
|
|
documented.
|
|
</p>
|
|
<a name="Encoders"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Encoders">11. Encoders</a></h1>
|
|
|
|
<p>Encoders are configured elements in FFmpeg which allow the encoding of
|
|
multimedia streams.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported native encoders
|
|
are enabled by default. Encoders requiring an external library must be enabled
|
|
manually via the corresponding <code>--enable-lib</code> option. You can list all
|
|
available encoders using the configure option <code>--list-encoders</code>.
|
|
</p>
|
|
<p>You can disable all the encoders with the configure option
|
|
<code>--disable-encoders</code> and selectively enable / disable single encoders
|
|
with the options <code>--enable-encoder=<var>ENCODER</var></code> /
|
|
<code>--disable-encoder=<var>ENCODER</var></code>.
|
|
</p>
|
|
<p>The option <code>-codecs</code> of the ff* tools will display the list of
|
|
enabled encoders.
|
|
</p>
|
|
|
|
<a name="Audio-Encoders"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Audio-Encoders">12. Audio Encoders</a></h1>
|
|
|
|
<p>A description of some of the currently available audio encoders
|
|
follows.
|
|
</p>
|
|
<a name="ac3-and-ac3_005ffixed"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-ac3-and-ac3_005ffixed">12.1 ac3 and ac3_fixed</a></h2>
|
|
|
|
<p>AC-3 audio encoders.
|
|
</p>
|
|
<p>These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
|
|
the undocumented RealAudio 3 (a.k.a. dnet).
|
|
</p>
|
|
<p>The <var>ac3</var> encoder uses floating-point math, while the <var>ac3_fixed</var>
|
|
encoder only uses fixed-point integer math. This does not mean that one is
|
|
always faster, just that one or the other may be better suited to a
|
|
particular system. The floating-point encoder will generally produce better
|
|
quality audio for a given bitrate. The <var>ac3_fixed</var> encoder is not the
|
|
default codec for any of the output formats, so it must be specified explicitly
|
|
using the option <code>-acodec ac3_fixed</code> in order to use it.
|
|
</p>
|
|
<a name="AC_002d3-Metadata"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-AC_002d3-Metadata">12.1.1 AC-3 Metadata</a></h3>
|
|
|
|
<p>The AC-3 metadata options are used to set parameters that describe the audio,
|
|
but in most cases do not affect the audio encoding itself. Some of the options
|
|
do directly affect or influence the decoding and playback of the resulting
|
|
bitstream, while others are just for informational purposes. A few of the
|
|
options will add bits to the output stream that could otherwise be used for
|
|
audio data, and will thus affect the quality of the output. Those will be
|
|
indicated accordingly with a note in the option list below.
|
|
</p>
|
|
<p>These parameters are described in detail in several publicly-available
|
|
documents.
|
|
</p><ul>
|
|
<li> <a href="http://www.atsc.org/cms/standards/a_52-2010.pdf">A/52:2010 - Digital Audio Compression (AC-3) (E-AC-3) Standard</a>
|
|
</li><li> <a href="http://www.atsc.org/cms/standards/a_54a_with_corr_1.pdf">A/54 - Guide to the Use of the ATSC Digital Television Standard</a>
|
|
</li><li> <a href="http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf">Dolby Metadata Guide</a>
|
|
</li><li> <a href="http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf">Dolby Digital Professional Encoding Guidelines</a>
|
|
</li></ul>
|
|
|
|
<a name="Metadata-Control-Options"></a>
|
|
<h4 class="subsubsection"><a href="ffmpeg.html#toc-Metadata-Control-Options">12.1.1.1 Metadata Control Options</a></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-per_frame_metadata <var>boolean</var></samp>’</dt>
|
|
<dd><p>Allow Per-Frame Metadata. Specifies if the encoder should check for changing
|
|
metadata for each frame.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>The metadata values set at initialization will be used for every frame in the
|
|
stream. (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>Metadata values can be changed before encoding each frame.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Downmix-Levels"></a>
|
|
<h4 class="subsubsection"><a href="ffmpeg.html#toc-Downmix-Levels">12.1.1.2 Downmix Levels</a></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-center_mixlev <var>level</var></samp>’</dt>
|
|
<dd><p>Center Mix Level. The amount of gain the decoder should apply to the center
|
|
channel when downmixing to stereo. This field will only be written to the
|
|
bitstream if a center channel is present. The value is specified as a scale
|
|
factor. There are 3 valid values:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0.707</samp>’</dt>
|
|
<dd><p>Apply -3dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.595</samp>’</dt>
|
|
<dd><p>Apply -4.5dB gain (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0.500</samp>’</dt>
|
|
<dd><p>Apply -6dB gain
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-surround_mixlev <var>level</var></samp>’</dt>
|
|
<dd><p>Surround Mix Level. The amount of gain the decoder should apply to the surround
|
|
channel(s) when downmixing to stereo. This field will only be written to the
|
|
bitstream if one or more surround channels are present. The value is specified
|
|
as a scale factor. There are 3 valid values:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0.707</samp>’</dt>
|
|
<dd><p>Apply -3dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.500</samp>’</dt>
|
|
<dd><p>Apply -6dB gain (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0.000</samp>’</dt>
|
|
<dd><p>Silence Surround Channel(s)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Audio-Production-Information"></a>
|
|
<h4 class="subsubsection"><a href="ffmpeg.html#toc-Audio-Production-Information">12.1.1.3 Audio Production Information</a></h4>
|
|
<p>Audio Production Information is optional information describing the mixing
|
|
environment. Either none or both of the fields are written to the bitstream.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-mixing_level <var>number</var></samp>’</dt>
|
|
<dd><p>Mixing Level. Specifies peak sound pressure level (SPL) in the production
|
|
environment when the mix was mastered. Valid values are 80 to 111, or -1 for
|
|
unknown or not indicated. The default value is -1, but that value cannot be
|
|
used if the Audio Production Information is written to the bitstream. Therefore,
|
|
if the <code>room_type</code> option is not the default value, the <code>mixing_level</code>
|
|
option must not be -1.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-room_type <var>type</var></samp>’</dt>
|
|
<dd><p>Room Type. Describes the equalization used during the final mixing session at
|
|
the studio or on the dubbing stage. A large room is a dubbing stage with the
|
|
industry standard X-curve equalization; a small room has flat equalization.
|
|
This field will not be written to the bitstream if both the <code>mixing_level</code>
|
|
option and the <code>room_type</code> option have the default values.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>notindicated</samp>’</dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>large</samp>’</dt>
|
|
<dd><p>Large Room
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dt> ‘<samp>small</samp>’</dt>
|
|
<dd><p>Small Room
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Other-Metadata-Options"></a>
|
|
<h4 class="subsubsection"><a href="ffmpeg.html#toc-Other-Metadata-Options">12.1.1.4 Other Metadata Options</a></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-copyright <var>boolean</var></samp>’</dt>
|
|
<dd><p>Copyright Indicator. Specifies whether a copyright exists for this audio.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>off</samp>’</dt>
|
|
<dd><p>No Copyright Exists (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>on</samp>’</dt>
|
|
<dd><p>Copyright Exists
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-dialnorm <var>value</var></samp>’</dt>
|
|
<dd><p>Dialogue Normalization. Indicates how far the average dialogue level of the
|
|
program is below digital 100% full scale (0 dBFS). This parameter determines a
|
|
level shift during audio reproduction that sets the average volume of the
|
|
dialogue to a preset level. The goal is to match volume level between program
|
|
sources. A value of -31dB will result in no volume level change, relative to
|
|
the source volume, during audio reproduction. Valid values are whole numbers in
|
|
the range -31 to -1, with -31 being the default.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-dsur_mode <var>mode</var></samp>’</dt>
|
|
<dd><p>Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
|
|
(Pro Logic). This field will only be written to the bitstream if the audio
|
|
stream is stereo. Using this option does <b>NOT</b> mean the encoder will actually
|
|
apply Dolby Surround processing.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>notindicated</samp>’</dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>off</samp>’</dt>
|
|
<dd><p>Not Dolby Surround Encoded
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dt> ‘<samp>on</samp>’</dt>
|
|
<dd><p>Dolby Surround Encoded
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-original <var>boolean</var></samp>’</dt>
|
|
<dd><p>Original Bit Stream Indicator. Specifies whether this audio is from the
|
|
original source and not a copy.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>off</samp>’</dt>
|
|
<dd><p>Not Original Source
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>on</samp>’</dt>
|
|
<dd><p>Original Source (default)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Extended-Bitstream-Information"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Extended-Bitstream-Information">12.1.2 Extended Bitstream Information</a></h3>
|
|
<p>The extended bitstream options are part of the Alternate Bit Stream Syntax as
|
|
specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
|
|
If any one parameter in a group is specified, all values in that group will be
|
|
written to the bitstream. Default values are used for those that are written
|
|
but have not been specified. If the mixing levels are written, the decoder
|
|
will use these values instead of the ones specified in the <code>center_mixlev</code>
|
|
and <code>surround_mixlev</code> options if it supports the Alternate Bit Stream
|
|
Syntax.
|
|
</p>
|
|
<a name="Extended-Bitstream-Information-_002d-Part-1"></a>
|
|
<h4 class="subsubsection"><a href="ffmpeg.html#toc-Extended-Bitstream-Information-_002d-Part-1">12.1.2.1 Extended Bitstream Information - Part 1</a></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-dmix_mode <var>mode</var></samp>’</dt>
|
|
<dd><p>Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
|
|
(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>notindicated</samp>’</dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>ltrt</samp>’</dt>
|
|
<dd><p>Lt/Rt Downmix Preferred
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dt> ‘<samp>loro</samp>’</dt>
|
|
<dd><p>Lo/Ro Downmix Preferred
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-ltrt_cmixlev <var>level</var></samp>’</dt>
|
|
<dd><p>Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
|
|
center channel when downmixing to stereo in Lt/Rt mode.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>1.414</samp>’</dt>
|
|
<dd><p>Apply +3dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>1.189</samp>’</dt>
|
|
<dd><p>Apply +1.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>1.000</samp>’</dt>
|
|
<dd><p>Apply 0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.841</samp>’</dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.707</samp>’</dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.595</samp>’</dt>
|
|
<dd><p>Apply -4.5dB gain (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0.500</samp>’</dt>
|
|
<dd><p>Apply -6.0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.000</samp>’</dt>
|
|
<dd><p>Silence Center Channel
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-ltrt_surmixlev <var>level</var></samp>’</dt>
|
|
<dd><p>Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
|
|
surround channel(s) when downmixing to stereo in Lt/Rt mode.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0.841</samp>’</dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.707</samp>’</dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.595</samp>’</dt>
|
|
<dd><p>Apply -4.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.500</samp>’</dt>
|
|
<dd><p>Apply -6.0dB gain (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0.000</samp>’</dt>
|
|
<dd><p>Silence Surround Channel(s)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-loro_cmixlev <var>level</var></samp>’</dt>
|
|
<dd><p>Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
|
|
center channel when downmixing to stereo in Lo/Ro mode.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>1.414</samp>’</dt>
|
|
<dd><p>Apply +3dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>1.189</samp>’</dt>
|
|
<dd><p>Apply +1.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>1.000</samp>’</dt>
|
|
<dd><p>Apply 0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.841</samp>’</dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.707</samp>’</dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.595</samp>’</dt>
|
|
<dd><p>Apply -4.5dB gain (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0.500</samp>’</dt>
|
|
<dd><p>Apply -6.0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.000</samp>’</dt>
|
|
<dd><p>Silence Center Channel
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-loro_surmixlev <var>level</var></samp>’</dt>
|
|
<dd><p>Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
|
|
surround channel(s) when downmixing to stereo in Lo/Ro mode.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0.841</samp>’</dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.707</samp>’</dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.595</samp>’</dt>
|
|
<dd><p>Apply -4.5dB gain
|
|
</p></dd>
|
|
<dt> ‘<samp>0.500</samp>’</dt>
|
|
<dd><p>Apply -6.0dB gain (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0.000</samp>’</dt>
|
|
<dd><p>Silence Surround Channel(s)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Extended-Bitstream-Information-_002d-Part-2"></a>
|
|
<h4 class="subsubsection"><a href="ffmpeg.html#toc-Extended-Bitstream-Information-_002d-Part-2">12.1.2.2 Extended Bitstream Information - Part 2</a></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-dsurex_mode <var>mode</var></samp>’</dt>
|
|
<dd><p>Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
|
|
(7.1 matrixed to 5.1). Using this option does <b>NOT</b> mean the encoder will actually
|
|
apply Dolby Surround EX processing.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>notindicated</samp>’</dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>on</samp>’</dt>
|
|
<dd><p>Dolby Surround EX Off
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dt> ‘<samp>off</samp>’</dt>
|
|
<dd><p>Dolby Surround EX On
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-dheadphone_mode <var>mode</var></samp>’</dt>
|
|
<dd><p>Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
|
|
encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
|
|
option does <b>NOT</b> mean the encoder will actually apply Dolby Headphone
|
|
processing.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>notindicated</samp>’</dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>on</samp>’</dt>
|
|
<dd><p>Dolby Headphone Off
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dt> ‘<samp>off</samp>’</dt>
|
|
<dd><p>Dolby Headphone On
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-ad_conv_type <var>type</var></samp>’</dt>
|
|
<dd><p>A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
|
|
conversion.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>standard</samp>’</dt>
|
|
<dd><p>Standard A/D Converter (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>hdcd</samp>’</dt>
|
|
<dd><p>HDCD A/D Converter
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Other-AC_002d3-Encoding-Options"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Other-AC_002d3-Encoding-Options">12.1.3 Other AC-3 Encoding Options</a></h3>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-stereo_rematrixing <var>boolean</var></samp>’</dt>
|
|
<dd><p>Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
|
|
is an optional AC-3 feature that increases quality by selectively encoding
|
|
the left/right channels as mid/side. This option is enabled by default, and it
|
|
is highly recommended that it be left as enabled except for testing purposes.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options">12.1.4 Floating-Point-Only AC-3 Encoding Options</a></h3>
|
|
|
|
<p>These options are only valid for the floating-point encoder and do not exist
|
|
for the fixed-point encoder due to the corresponding features not being
|
|
implemented in fixed-point.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-channel_coupling <var>boolean</var></samp>’</dt>
|
|
<dd><p>Enables/Disables use of channel coupling, which is an optional AC-3 feature
|
|
that increases quality by combining high frequency information from multiple
|
|
channels into a single channel. The per-channel high frequency information is
|
|
sent with less accuracy in both the frequency and time domains. This allows
|
|
more bits to be used for lower frequencies while preserving enough information
|
|
to reconstruct the high frequencies. This option is enabled by default for the
|
|
floating-point encoder and should generally be left as enabled except for
|
|
testing purposes or to increase encoding speed.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>-1</samp>’</dt>
|
|
<dt> ‘<samp>auto</samp>’</dt>
|
|
<dd><p>Selected by Encoder (default)
|
|
</p></dd>
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dt> ‘<samp>off</samp>’</dt>
|
|
<dd><p>Disable Channel Coupling
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dt> ‘<samp>on</samp>’</dt>
|
|
<dd><p>Enable Channel Coupling
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>-cpl_start_band <var>number</var></samp>’</dt>
|
|
<dd><p>Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
|
|
value higher than the bandwidth is used, it will be reduced to 1 less than the
|
|
coupling end band. If <var>auto</var> is used, the start band will be determined by
|
|
the encoder based on the bit rate, sample rate, and channel layout. This option
|
|
has no effect if channel coupling is disabled.
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>-1</samp>’</dt>
|
|
<dt> ‘<samp>auto</samp>’</dt>
|
|
<dd><p>Selected by Encoder (default)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
|
|
<a name="Video-Encoders"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Video-Encoders">13. Video Encoders</a></h1>
|
|
|
|
<p>A description of some of the currently available video encoders
|
|
follows.
|
|
</p>
|
|
<a name="libvpx"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-libvpx">13.1 libvpx</a></h2>
|
|
|
|
<p>VP8 format supported through libvpx.
|
|
</p>
|
|
<p>Requires the presence of the libvpx headers and library during configuration.
|
|
You need to explicitly configure the build with <code>--enable-libvpx</code>.
|
|
</p>
|
|
<a name="Options-5"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Options-5">13.1.1 Options</a></h3>
|
|
|
|
<p>Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>threads</samp>’</dt>
|
|
<dd><p>g_threads
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>profile</samp>’</dt>
|
|
<dd><p>g_profile
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>vb</samp>’</dt>
|
|
<dd><p>rc_target_bitrate
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>g</samp>’</dt>
|
|
<dd><p>kf_max_dist
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>keyint_min</samp>’</dt>
|
|
<dd><p>kf_min_dist
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>qmin</samp>’</dt>
|
|
<dd><p>rc_min_quantizer
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>qmax</samp>’</dt>
|
|
<dd><p>rc_max_quantizer
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>bufsize, vb</samp>’</dt>
|
|
<dd><p>rc_buf_sz
|
|
<code>(bufsize * 1000 / vb)</code>
|
|
</p>
|
|
<p>rc_buf_optimal_sz
|
|
<code>(bufsize * 1000 / vb * 5 / 6)</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rc_init_occupancy, vb</samp>’</dt>
|
|
<dd><p>rc_buf_initial_sz
|
|
<code>(rc_init_occupancy * 1000 / vb)</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rc_buffer_aggressivity</samp>’</dt>
|
|
<dd><p>rc_undershoot_pct
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>skip_threshold</samp>’</dt>
|
|
<dd><p>rc_dropframe_thresh
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>qcomp</samp>’</dt>
|
|
<dd><p>rc_2pass_vbr_bias_pct
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>maxrate, vb</samp>’</dt>
|
|
<dd><p>rc_2pass_vbr_maxsection_pct
|
|
<code>(maxrate * 100 / vb)</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>minrate, vb</samp>’</dt>
|
|
<dd><p>rc_2pass_vbr_minsection_pct
|
|
<code>(minrate * 100 / vb)</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>minrate, maxrate, vb</samp>’</dt>
|
|
<dd><p><code>VPX_CBR</code>
|
|
<code>(minrate == maxrate == vb)</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>crf</samp>’</dt>
|
|
<dd><p><code>VPX_CQ</code>, <code>VP8E_SET_CQ_LEVEL</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>quality</samp>’</dt>
|
|
<dd><dl compact="compact">
|
|
<dt> ‘<samp><var>best</var></samp>’</dt>
|
|
<dd><p><code>VPX_DL_BEST_QUALITY</code>
|
|
</p></dd>
|
|
<dt> ‘<samp><var>good</var></samp>’</dt>
|
|
<dd><p><code>VPX_DL_GOOD_QUALITY</code>
|
|
</p></dd>
|
|
<dt> ‘<samp><var>realtime</var></samp>’</dt>
|
|
<dd><p><code>VPX_DL_REALTIME</code>
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>speed</samp>’</dt>
|
|
<dd><p><code>VP8E_SET_CPUUSED</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>nr</samp>’</dt>
|
|
<dd><p><code>VP8E_SET_NOISE_SENSITIVITY</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>mb_threshold</samp>’</dt>
|
|
<dd><p><code>VP8E_SET_STATIC_THRESHOLD</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>slices</samp>’</dt>
|
|
<dd><p><code>VP8E_SET_TOKEN_PARTITIONS</code>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>Alternate reference frame related</samp>’</dt>
|
|
<dd><dl compact="compact">
|
|
<dt> ‘<samp>vp8flags altref</samp>’</dt>
|
|
<dd><p><code>VP8E_SET_ENABLEAUTOALTREF</code>
|
|
</p></dd>
|
|
<dt> ‘<samp><var>arnr_max_frames</var></samp>’</dt>
|
|
<dd><p><code>VP8E_SET_ARNR_MAXFRAMES</code>
|
|
</p></dd>
|
|
<dt> ‘<samp><var>arnr_type</var></samp>’</dt>
|
|
<dd><p><code>VP8E_SET_ARNR_TYPE</code>
|
|
</p></dd>
|
|
<dt> ‘<samp><var>arnr_strength</var></samp>’</dt>
|
|
<dd><p><code>VP8E_SET_ARNR_STRENGTH</code>
|
|
</p></dd>
|
|
<dt> ‘<samp><var>rc_lookahead</var></samp>’</dt>
|
|
<dd><p>g_lag_in_frames
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>vp8flags error_resilient</samp>’</dt>
|
|
<dd><p>g_error_resilient
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>For more information about libvpx see:
|
|
<a href="http://www.webmproject.org/">http://www.webmproject.org/</a>
|
|
</p>
|
|
<a name="libx264"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-libx264">13.2 libx264</a></h2>
|
|
|
|
<p>H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 format supported through
|
|
libx264.
|
|
</p>
|
|
<p>Requires the presence of the libx264 headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libx264</code>.
|
|
</p>
|
|
<a name="Options-4"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Options-4">13.2.1 Options</a></h3>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>preset <var>preset_name</var></samp>’</dt>
|
|
<dd><p>Set the encoding preset.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>tune <var>tune_name</var></samp>’</dt>
|
|
<dd><p>Tune the encoding params.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>fastfirstpass <var>bool</var></samp>’</dt>
|
|
<dd><p>Use fast settings when encoding first pass, default value is 1.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>profile <var>profile_name</var></samp>’</dt>
|
|
<dd><p>Set profile restrictions.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>level <var>level</var></samp>’</dt>
|
|
<dd><p>Specify level (as defined by Annex A).
|
|
Deprecated in favor of <var>x264opts</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>passlogfile <var>filename</var></samp>’</dt>
|
|
<dd><p>Specify filename for 2 pass stats.
|
|
Deprecated in favor of <var>x264opts</var> (see <var>stats</var> libx264 option).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>wpredp <var>wpred_type</var></samp>’</dt>
|
|
<dd><p>Specify Weighted prediction for P-frames.
|
|
Deprecated in favor of <var>x264opts</var> (see <var>weightp</var> libx264 option).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>x264opts <var>options</var></samp>’</dt>
|
|
<dd><p>Allow to set any x264 option, see x264 –fullhelp for a list.
|
|
</p>
|
|
<p><var>options</var> is a list of <var>key</var>=<var>value</var> couples separated by
|
|
":".
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>For example to specify libx264 encoding options with <code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
|
|
</pre></td></tr></table>
|
|
|
|
<p>For more information about libx264 and the supported options see:
|
|
<a href="http://www.videolan.org/developers/x264.html">http://www.videolan.org/developers/x264.html</a>
|
|
</p>
|
|
<a name="Demuxers"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Demuxers">14. Demuxers</a></h1>
|
|
|
|
<p>Demuxers are configured elements in FFmpeg which allow to read the
|
|
multimedia streams from a particular type of file.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported demuxers
|
|
are enabled by default. You can list all available ones using the
|
|
configure option "–list-demuxers".
|
|
</p>
|
|
<p>You can disable all the demuxers using the configure option
|
|
"–disable-demuxers", and selectively enable a single demuxer with
|
|
the option "–enable-demuxer=<var>DEMUXER</var>", or disable it
|
|
with the option "–disable-demuxer=<var>DEMUXER</var>".
|
|
</p>
|
|
<p>The option "-formats" of the ff* tools will display the list of
|
|
enabled demuxers.
|
|
</p>
|
|
<p>The description of some of the currently available demuxers follows.
|
|
</p>
|
|
<a name="image2-2"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-image2-2">14.1 image2</a></h2>
|
|
|
|
<p>Image file demuxer.
|
|
</p>
|
|
<p>This demuxer reads from a list of image files specified by a pattern.
|
|
</p>
|
|
<p>The pattern may contain the string "%d" or "%0<var>N</var>d", which
|
|
specifies the position of the characters representing a sequential
|
|
number in each filename matched by the pattern. If the form
|
|
"%d0<var>N</var>d" is used, the string representing the number in each
|
|
filename is 0-padded and <var>N</var> is the total number of 0-padded
|
|
digits representing the number. The literal character ’%’ can be
|
|
specified in the pattern with the string "%%".
|
|
</p>
|
|
<p>If the pattern contains "%d" or "%0<var>N</var>d", the first filename of
|
|
the file list specified by the pattern must contain a number
|
|
inclusively contained between 0 and 4, all the following numbers must
|
|
be sequential. This limitation may be hopefully fixed.
|
|
</p>
|
|
<p>The pattern may contain a suffix which is used to automatically
|
|
determine the format of the images contained in the files.
|
|
</p>
|
|
<p>For example the pattern "img-%03d.bmp" will match a sequence of
|
|
filenames of the form ‘<tt>img-001.bmp</tt>’, ‘<tt>img-002.bmp</tt>’, ...,
|
|
‘<tt>img-010.bmp</tt>’, etc.; the pattern "i%%m%%g-%d.jpg" will match a
|
|
sequence of filenames of the form ‘<tt>i%m%g-1.jpg</tt>’,
|
|
‘<tt>i%m%g-2.jpg</tt>’, ..., ‘<tt>i%m%g-10.jpg</tt>’, etc.
|
|
</p>
|
|
<p>The size, the pixel format, and the format of each image must be the
|
|
same for all the files in the sequence.
|
|
</p>
|
|
<p>The following example shows how to use <code>ffmpeg</code> for creating a
|
|
video from the images in the file sequence ‘<tt>img-001.jpeg</tt>’,
|
|
‘<tt>img-002.jpeg</tt>’, ..., assuming an input frame rate of 10 frames per
|
|
second:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i 'img-%03d.jpeg' -r 10 out.mkv
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that the pattern must not necessarily contain "%d" or
|
|
"%0<var>N</var>d", for example to convert a single image file
|
|
‘<tt>img.jpeg</tt>’ you can employ the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i img.jpeg img.png
|
|
</pre></td></tr></table>
|
|
|
|
<a name="applehttp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-applehttp">14.2 applehttp</a></h2>
|
|
|
|
<p>Apple HTTP Live Streaming demuxer.
|
|
</p>
|
|
<p>This demuxer presents all AVStreams from all variant streams.
|
|
The id field is set to the bitrate variant index number. By setting
|
|
the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
|
|
the caller can decide which variant streams to actually receive.
|
|
The total bitrate of the variant that the stream belongs to is
|
|
available in a metadata key named "variant_bitrate".
|
|
</p>
|
|
<a name="sbg"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-sbg">14.3 sbg</a></h2>
|
|
|
|
<p>SBaGen script demuxer.
|
|
</p>
|
|
<p>This demuxer reads the script language used by SBaGen
|
|
<a href="http://uazu.net/sbagen/">http://uazu.net/sbagen/</a> to generate binaural beats sessions. A SBG
|
|
script looks like that:
|
|
</p><table><tr><td> </td><td><pre class="example">-SE
|
|
a: 300-2.5/3 440+4.5/0
|
|
b: 300-2.5/0 440+4.5/3
|
|
off: -
|
|
NOW == a
|
|
+0:07:00 == b
|
|
+0:14:00 == a
|
|
+0:21:00 == b
|
|
+0:30:00 off
|
|
</pre></td></tr></table>
|
|
|
|
<p>A SBG script can mix absolute and relative timestamps. If the script uses
|
|
either only absolute timestamps (including the script start time) or only
|
|
relative ones, then its layout is fixed, and the conversion is
|
|
straightforward. On the other hand, if the script mixes both kind of
|
|
timestamps, then the <var>NOW</var> reference for relative timestamps will be
|
|
taken from the current time of day at the time the script is read, and the
|
|
script layout will be frozen according to that reference. That means that if
|
|
the script is directly played, the actual times will match the absolute
|
|
timestamps up to the sound controller’s clock accuracy, but if the user
|
|
somehow pauses the playback or seeks, all times will be shifted accordingly.
|
|
</p>
|
|
<a name="Muxers"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Muxers">15. Muxers</a></h1>
|
|
|
|
<p>Muxers are configured elements in FFmpeg which allow writing
|
|
multimedia streams to a particular type of file.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported muxers
|
|
are enabled by default. You can list all available muxers using the
|
|
configure option <code>--list-muxers</code>.
|
|
</p>
|
|
<p>You can disable all the muxers with the configure option
|
|
<code>--disable-muxers</code> and selectively enable / disable single muxers
|
|
with the options <code>--enable-muxer=<var>MUXER</var></code> /
|
|
<code>--disable-muxer=<var>MUXER</var></code>.
|
|
</p>
|
|
<p>The option <code>-formats</code> of the ff* tools will display the list of
|
|
enabled muxers.
|
|
</p>
|
|
<p>A description of some of the currently available muxers follows.
|
|
</p>
|
|
<p><a name="crc"></a>
|
|
</p><a name="crc-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-crc-1">15.1 crc</a></h2>
|
|
|
|
<p>CRC (Cyclic Redundancy Check) testing format.
|
|
</p>
|
|
<p>This muxer computes and prints the Adler-32 CRC of all the input audio
|
|
and video frames. By default audio frames are converted to signed
|
|
16-bit raw audio and video frames to raw video before computing the
|
|
CRC.
|
|
</p>
|
|
<p>The output of the muxer consists of a single line of the form:
|
|
CRC=0x<var>CRC</var>, where <var>CRC</var> is a hexadecimal number 0-padded to
|
|
8 digits containing the CRC for all the decoded input frames.
|
|
</p>
|
|
<p>For example to compute the CRC of the input, and store it in the file
|
|
‘<tt>out.crc</tt>’:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -f crc out.crc
|
|
</pre></td></tr></table>
|
|
|
|
<p>You can print the CRC to stdout with the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -f crc -
|
|
</pre></td></tr></table>
|
|
|
|
<p>You can select the output format of each frame with <code>ffmpeg</code> by
|
|
specifying the audio and video codec and format. For example to
|
|
compute the CRC of the input audio converted to PCM unsigned 8-bit
|
|
and the input video converted to MPEG-2 video, use the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
|
|
</pre></td></tr></table>
|
|
|
|
<p>See also the <a href="#framecrc">framecrc</a> muxer.
|
|
</p>
|
|
<p><a name="framecrc"></a>
|
|
</p><a name="framecrc-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-framecrc-1">15.2 framecrc</a></h2>
|
|
|
|
<p>Per-frame CRC (Cyclic Redundancy Check) testing format.
|
|
</p>
|
|
<p>This muxer computes and prints the Adler-32 CRC for each decoded audio
|
|
and video frame. By default audio frames are converted to signed
|
|
16-bit raw audio and video frames to raw video before computing the
|
|
CRC.
|
|
</p>
|
|
<p>The output of the muxer consists of a line for each audio and video
|
|
frame of the form: <var>stream_index</var>, <var>frame_dts</var>,
|
|
<var>frame_size</var>, 0x<var>CRC</var>, where <var>CRC</var> is a hexadecimal
|
|
number 0-padded to 8 digits containing the CRC of the decoded frame.
|
|
</p>
|
|
<p>For example to compute the CRC of each decoded frame in the input, and
|
|
store it in the file ‘<tt>out.crc</tt>’:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -f framecrc out.crc
|
|
</pre></td></tr></table>
|
|
|
|
<p>You can print the CRC of each decoded frame to stdout with the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -f framecrc -
|
|
</pre></td></tr></table>
|
|
|
|
<p>You can select the output format of each frame with <code>ffmpeg</code> by
|
|
specifying the audio and video codec and format. For example, to
|
|
compute the CRC of each decoded input audio frame converted to PCM
|
|
unsigned 8-bit and of each decoded input video frame converted to
|
|
MPEG-2 video, use the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
|
|
</pre></td></tr></table>
|
|
|
|
<p>See also the <a href="#crc">crc</a> muxer.
|
|
</p>
|
|
<p><a name="image2"></a>
|
|
</p><a name="image2-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-image2-1">15.3 image2</a></h2>
|
|
|
|
<p>Image file muxer.
|
|
</p>
|
|
<p>The image file muxer writes video frames to image files.
|
|
</p>
|
|
<p>The output filenames are specified by a pattern, which can be used to
|
|
produce sequentially numbered series of files.
|
|
The pattern may contain the string "%d" or "%0<var>N</var>d", this string
|
|
specifies the position of the characters representing a numbering in
|
|
the filenames. If the form "%0<var>N</var>d" is used, the string
|
|
representing the number in each filename is 0-padded to <var>N</var>
|
|
digits. The literal character ’%’ can be specified in the pattern with
|
|
the string "%%".
|
|
</p>
|
|
<p>If the pattern contains "%d" or "%0<var>N</var>d", the first filename of
|
|
the file list specified will contain the number 1, all the following
|
|
numbers will be sequential.
|
|
</p>
|
|
<p>The pattern may contain a suffix which is used to automatically
|
|
determine the format of the image files to write.
|
|
</p>
|
|
<p>For example the pattern "img-%03d.bmp" will specify a sequence of
|
|
filenames of the form ‘<tt>img-001.bmp</tt>’, ‘<tt>img-002.bmp</tt>’, ...,
|
|
‘<tt>img-010.bmp</tt>’, etc.
|
|
The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
|
|
form ‘<tt>img%-1.jpg</tt>’, ‘<tt>img%-2.jpg</tt>’, ..., ‘<tt>img%-10.jpg</tt>’,
|
|
etc.
|
|
</p>
|
|
<p>The following example shows how to use <code>ffmpeg</code> for creating a
|
|
sequence of files ‘<tt>img-001.jpeg</tt>’, ‘<tt>img-002.jpeg</tt>’, ...,
|
|
taking one image every second from the input video:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that with <code>ffmpeg</code>, if the format is not specified with the
|
|
<code>-f</code> option and the output filename specifies an image file
|
|
format, the image2 muxer is automatically selected, so the previous
|
|
command can be written as:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note also that the pattern must not necessarily contain "%d" or
|
|
"%0<var>N</var>d", for example to create a single image file
|
|
‘<tt>img.jpeg</tt>’ from the input video you can employ the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
|
|
</pre></td></tr></table>
|
|
|
|
<p>The image muxer supports the .Y.U.V image file format. This format is
|
|
special in that that each image frame consists of three files, for
|
|
each of the YUV420P components. To read or write this image file format,
|
|
specify the name of the ’.Y’ file. The muxer will automatically open the
|
|
’.U’ and ’.V’ files as required.
|
|
</p>
|
|
<a name="mov"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mov">15.4 mov</a></h2>
|
|
|
|
<p>MOV / MP4 muxer
|
|
</p>
|
|
<p>The muxer options are:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-moov_size <var>bytes</var></samp>’</dt>
|
|
<dd><p>Reserves space for the moov atom at the beginning of the file instead of placing the
|
|
moov atom at the end. If the space reserved is insufficient, muxing will fail.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="mpegts"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mpegts">15.5 mpegts</a></h2>
|
|
|
|
<p>MPEG transport stream muxer.
|
|
</p>
|
|
<p>This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
|
|
</p>
|
|
<p>The muxer options are:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>-mpegts_original_network_id <var>number</var></samp>’</dt>
|
|
<dd><p>Set the original_network_id (default 0x0001). This is unique identifier
|
|
of a network in DVB. Its main use is in the unique identification of a
|
|
service through the path Original_Network_ID, Transport_Stream_ID.
|
|
</p></dd>
|
|
<dt> ‘<samp>-mpegts_transport_stream_id <var>number</var></samp>’</dt>
|
|
<dd><p>Set the transport_stream_id (default 0x0001). This identifies a
|
|
transponder in DVB.
|
|
</p></dd>
|
|
<dt> ‘<samp>-mpegts_service_id <var>number</var></samp>’</dt>
|
|
<dd><p>Set the service_id (default 0x0001) also known as program in DVB.
|
|
</p></dd>
|
|
<dt> ‘<samp>-mpegts_pmt_start_pid <var>number</var></samp>’</dt>
|
|
<dd><p>Set the first PID for PMT (default 0x1000, max 0x1f00).
|
|
</p></dd>
|
|
<dt> ‘<samp>-mpegts_start_pid <var>number</var></samp>’</dt>
|
|
<dd><p>Set the first PID for data packets (default 0x0100, max 0x0f00).
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The recognized metadata settings in mpegts muxer are <code>service_provider</code>
|
|
and <code>service_name</code>. If they are not set the default for
|
|
<code>service_provider</code> is "FFmpeg" and the default for
|
|
<code>service_name</code> is "Service01".
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i file.mpg -c copy \
|
|
-mpegts_original_network_id 0x1122 \
|
|
-mpegts_transport_stream_id 0x3344 \
|
|
-mpegts_service_id 0x5566 \
|
|
-mpegts_pmt_start_pid 0x1500 \
|
|
-mpegts_start_pid 0x150 \
|
|
-metadata service_provider="Some provider" \
|
|
-metadata service_name="Some Channel" \
|
|
-y out.ts
|
|
</pre></td></tr></table>
|
|
|
|
<a name="null"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-null">15.6 null</a></h2>
|
|
|
|
<p>Null muxer.
|
|
</p>
|
|
<p>This muxer does not generate any output file, it is mainly useful for
|
|
testing or benchmarking purposes.
|
|
</p>
|
|
<p>For example to benchmark decoding with <code>ffmpeg</code> you can use the
|
|
command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -benchmark -i INPUT -f null out.null
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that the above command does not read or write the ‘<tt>out.null</tt>’
|
|
file, but specifying the output file is required by the <code>ffmpeg</code>
|
|
syntax.
|
|
</p>
|
|
<p>Alternatively you can write the command as:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -benchmark -i INPUT -f null -
|
|
</pre></td></tr></table>
|
|
|
|
<a name="matroska"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-matroska">15.7 matroska</a></h2>
|
|
|
|
<p>Matroska container muxer.
|
|
</p>
|
|
<p>This muxer implements the matroska and webm container specs.
|
|
</p>
|
|
<p>The recognized metadata settings in this muxer are:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>title=<var>title name</var></samp>’</dt>
|
|
<dd><p>Name provided to a single track
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>language=<var>language name</var></samp>’</dt>
|
|
<dd><p>Specifies the language of the track in the Matroska languages form
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>stereo_mode=<var>mode</var></samp>’</dt>
|
|
<dd><p>Stereo 3D video layout of two views in a single video track
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>mono</samp>’</dt>
|
|
<dd><p>video is not stereo
|
|
</p></dd>
|
|
<dt> ‘<samp>left_right</samp>’</dt>
|
|
<dd><p>Both views are arranged side by side, Left-eye view is on the left
|
|
</p></dd>
|
|
<dt> ‘<samp>bottom_top</samp>’</dt>
|
|
<dd><p>Both views are arranged in top-bottom orientation, Left-eye view is at bottom
|
|
</p></dd>
|
|
<dt> ‘<samp>top_bottom</samp>’</dt>
|
|
<dd><p>Both views are arranged in top-bottom orientation, Left-eye view is on top
|
|
</p></dd>
|
|
<dt> ‘<samp>checkerboard_rl</samp>’</dt>
|
|
<dd><p>Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
|
|
</p></dd>
|
|
<dt> ‘<samp>checkerboard_lr</samp>’</dt>
|
|
<dd><p>Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
|
|
</p></dd>
|
|
<dt> ‘<samp>row_interleaved_rl</samp>’</dt>
|
|
<dd><p>Each view is constituted by a row based interleaving, Right-eye view is first row
|
|
</p></dd>
|
|
<dt> ‘<samp>row_interleaved_lr</samp>’</dt>
|
|
<dd><p>Each view is constituted by a row based interleaving, Left-eye view is first row
|
|
</p></dd>
|
|
<dt> ‘<samp>col_interleaved_rl</samp>’</dt>
|
|
<dd><p>Both views are arranged in a column based interleaving manner, Right-eye view is first column
|
|
</p></dd>
|
|
<dt> ‘<samp>col_interleaved_lr</samp>’</dt>
|
|
<dd><p>Both views are arranged in a column based interleaving manner, Left-eye view is first column
|
|
</p></dd>
|
|
<dt> ‘<samp>anaglyph_cyan_red</samp>’</dt>
|
|
<dd><p>All frames are in anaglyph format viewable through red-cyan filters
|
|
</p></dd>
|
|
<dt> ‘<samp>right_left</samp>’</dt>
|
|
<dd><p>Both views are arranged side by side, Right-eye view is on the left
|
|
</p></dd>
|
|
<dt> ‘<samp>anaglyph_green_magenta</samp>’</dt>
|
|
<dd><p>All frames are in anaglyph format viewable through green-magenta filters
|
|
</p></dd>
|
|
<dt> ‘<samp>block_lr</samp>’</dt>
|
|
<dd><p>Both eyes laced in one Block, Left-eye view is first
|
|
</p></dd>
|
|
<dt> ‘<samp>block_rl</samp>’</dt>
|
|
<dd><p>Both eyes laced in one Block, Right-eye view is first
|
|
</p></dd>
|
|
</dl>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>For example a 3D WebM clip can be created using the following command line:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
|
|
</pre></td></tr></table>
|
|
|
|
<a name="segment"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-segment">15.8 segment</a></h2>
|
|
|
|
<p>Basic stream segmenter.
|
|
</p>
|
|
<p>The segmenter muxer outputs streams to a number of separate files of nearly
|
|
fixed duration. Output filename pattern can be set in a fashion similar to
|
|
<a href="#image2">image2</a>.
|
|
</p>
|
|
<p>Every segment starts with a video keyframe, if a video stream is present.
|
|
The segment muxer works best with a single constant frame rate video.
|
|
</p>
|
|
<p>Optionally it can generate a flat list of the created segments, one segment
|
|
per line.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>segment_format <var>format</var></samp>’</dt>
|
|
<dd><p>Override the inner container format, by default it is guessed by the filename
|
|
extension.
|
|
</p></dd>
|
|
<dt> ‘<samp>segment_time <var>t</var></samp>’</dt>
|
|
<dd><p>Set segment duration to <var>t</var> seconds.
|
|
</p></dd>
|
|
<dt> ‘<samp>segment_list <var>name</var></samp>’</dt>
|
|
<dd><p>Generate also a listfile named <var>name</var>.
|
|
</p></dd>
|
|
<dt> ‘<samp>segment_list_size <var>size</var></samp>’</dt>
|
|
<dd><p>Overwrite the listfile once it reaches <var>size</var> entries.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i in.mkv -c copy -map 0 -f segment -list out.list out%03d.nut
|
|
</pre></td></tr></table>
|
|
|
|
|
|
<a name="Input-Devices"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Input-Devices">16. Input Devices</a></h1>
|
|
|
|
<p>Input devices are configured elements in FFmpeg which allow to access
|
|
the data coming from a multimedia device attached to your system.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported input devices
|
|
are enabled by default. You can list all available ones using the
|
|
configure option "–list-indevs".
|
|
</p>
|
|
<p>You can disable all the input devices using the configure option
|
|
"–disable-indevs", and selectively enable an input device using the
|
|
option "–enable-indev=<var>INDEV</var>", or you can disable a particular
|
|
input device using the option "–disable-indev=<var>INDEV</var>".
|
|
</p>
|
|
<p>The option "-formats" of the ff* tools will display the list of
|
|
supported input devices (amongst the demuxers).
|
|
</p>
|
|
<p>A description of the currently available input devices follows.
|
|
</p>
|
|
<a name="alsa-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-alsa-1">16.1 alsa</a></h2>
|
|
|
|
<p>ALSA (Advanced Linux Sound Architecture) input device.
|
|
</p>
|
|
<p>To enable this input device during configuration you need libasound
|
|
installed on your system.
|
|
</p>
|
|
<p>This device allows capturing from an ALSA device. The name of the
|
|
device to capture has to be an ALSA card identifier.
|
|
</p>
|
|
<p>An ALSA identifier has the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example">hw:<var>CARD</var>[,<var>DEV</var>[,<var>SUBDEV</var>]]
|
|
</pre></td></tr></table>
|
|
|
|
<p>where the <var>DEV</var> and <var>SUBDEV</var> components are optional.
|
|
</p>
|
|
<p>The three arguments (in order: <var>CARD</var>,<var>DEV</var>,<var>SUBDEV</var>)
|
|
specify card number or identifier, device number and subdevice number
|
|
(-1 means any).
|
|
</p>
|
|
<p>To see the list of cards currently recognized by your system check the
|
|
files ‘<tt>/proc/asound/cards</tt>’ and ‘<tt>/proc/asound/devices</tt>’.
|
|
</p>
|
|
<p>For example to capture with <code>ffmpeg</code> from an ALSA device with
|
|
card id 0, you may run the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f alsa -i hw:0 alsaout.wav
|
|
</pre></td></tr></table>
|
|
|
|
<p>For more information see:
|
|
<a href="http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html">http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html</a>
|
|
</p>
|
|
<a name="bktr"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-bktr">16.2 bktr</a></h2>
|
|
|
|
<p>BSD video input device.
|
|
</p>
|
|
<a name="dshow"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-dshow">16.3 dshow</a></h2>
|
|
|
|
<p>Windows DirectShow input device.
|
|
</p>
|
|
<p>DirectShow support is enabled when FFmpeg is built with mingw-w64.
|
|
Currently only audio and video devices are supported.
|
|
</p>
|
|
<p>Multiple devices may be opened as separate inputs, but they may also be
|
|
opened on the same input, which should improve synchronism between them.
|
|
</p>
|
|
<p>The input name should be in the format:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example"><var>TYPE</var>=<var>NAME</var>[:<var>TYPE</var>=<var>NAME</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p>where <var>TYPE</var> can be either <var>audio</var> or <var>video</var>,
|
|
and <var>NAME</var> is the device’s name.
|
|
</p>
|
|
<a name="Options-2"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Options-2">16.3.1 Options</a></h3>
|
|
|
|
<p>If no options are specified, the device’s defaults are used.
|
|
If the device does not support the requested options, it will
|
|
fail to open.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>video_size</samp>’</dt>
|
|
<dd><p>Set the video size in the captured video.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>framerate</samp>’</dt>
|
|
<dd><p>Set the framerate in the captured video.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sample_rate</samp>’</dt>
|
|
<dd><p>Set the sample rate (in Hz) of the captured audio.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sample_size</samp>’</dt>
|
|
<dd><p>Set the sample size (in bits) of the captured audio.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>channels</samp>’</dt>
|
|
<dd><p>Set the number of channels in the captured audio.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>list_devices</samp>’</dt>
|
|
<dd><p>If set to ‘<samp>true</samp>’, print a list of devices and exit.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>list_options</samp>’</dt>
|
|
<dd><p>If set to ‘<samp>true</samp>’, print a list of selected device’s options
|
|
and exit.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>video_device_number</samp>’</dt>
|
|
<dd><p>Set video device number for devices with same name (starts at 0,
|
|
defaults to 0).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>audio_device_number</samp>’</dt>
|
|
<dd><p>Set audio device number for devices with same name (starts at 0,
|
|
defaults to 0).
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Examples-7"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-7">16.3.2 Examples</a></h3>
|
|
|
|
<ul>
|
|
<li>
|
|
Print the list of DirectShow supported devices and exit:
|
|
<table><tr><td> </td><td><pre class="example">$ ffmpeg -list_devices true -f dshow -i dummy
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Open video device <var>Camera</var>:
|
|
<table><tr><td> </td><td><pre class="example">$ ffmpeg -f dshow -i video="Camera"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Open second video device with name <var>Camera</var>:
|
|
<table><tr><td> </td><td><pre class="example">$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Open video device <var>Camera</var> and audio device <var>Microphone</var>:
|
|
<table><tr><td> </td><td><pre class="example">$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Print the list of supported options in selected device and exit:
|
|
<table><tr><td> </td><td><pre class="example">$ ffmpeg -list_options true -f dshow -i video="Camera"
|
|
</pre></td></tr></table>
|
|
|
|
</li></ul>
|
|
|
|
<a name="dv1394"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-dv1394">16.4 dv1394</a></h2>
|
|
|
|
<p>Linux DV 1394 input device.
|
|
</p>
|
|
<a name="fbdev"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-fbdev">16.5 fbdev</a></h2>
|
|
|
|
<p>Linux framebuffer input device.
|
|
</p>
|
|
<p>The Linux framebuffer is a graphic hardware-independent abstraction
|
|
layer to show graphics on a computer monitor, typically on the
|
|
console. It is accessed through a file device node, usually
|
|
‘<tt>/dev/fb0</tt>’.
|
|
</p>
|
|
<p>For more detailed information read the file
|
|
Documentation/fb/framebuffer.txt included in the Linux source tree.
|
|
</p>
|
|
<p>To record from the framebuffer device ‘<tt>/dev/fb0</tt>’ with
|
|
<code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
|
|
</pre></td></tr></table>
|
|
|
|
<p>You can take a single screenshot image with the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
|
|
</pre></td></tr></table>
|
|
|
|
<p>See also <a href="http://linux-fbdev.sourceforge.net/">http://linux-fbdev.sourceforge.net/</a>, and fbset(1).
|
|
</p>
|
|
<a name="jack"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-jack">16.6 jack</a></h2>
|
|
|
|
<p>JACK input device.
|
|
</p>
|
|
<p>To enable this input device during configuration you need libjack
|
|
installed on your system.
|
|
</p>
|
|
<p>A JACK input device creates one or more JACK writable clients, one for
|
|
each audio channel, with name <var>client_name</var>:input_<var>N</var>, where
|
|
<var>client_name</var> is the name provided by the application, and <var>N</var>
|
|
is a number which identifies the channel.
|
|
Each writable client will send the acquired data to the FFmpeg input
|
|
device.
|
|
</p>
|
|
<p>Once you have created one or more JACK readable clients, you need to
|
|
connect them to one or more JACK writable clients.
|
|
</p>
|
|
<p>To connect or disconnect JACK clients you can use the <code>jack_connect</code>
|
|
and <code>jack_disconnect</code> programs, or do it through a graphical interface,
|
|
for example with <code>qjackctl</code>.
|
|
</p>
|
|
<p>To list the JACK clients and their properties you can invoke the command
|
|
<code>jack_lsp</code>.
|
|
</p>
|
|
<p>Follows an example which shows how to capture a JACK readable client
|
|
with <code>ffmpeg</code>.
|
|
</p><table><tr><td> </td><td><pre class="example"># Create a JACK writable client with name "ffmpeg".
|
|
$ ffmpeg -f jack -i ffmpeg -y out.wav
|
|
|
|
# Start the sample jack_metro readable client.
|
|
$ jack_metro -b 120 -d 0.2 -f 4000
|
|
|
|
# List the current JACK clients.
|
|
$ jack_lsp -c
|
|
system:capture_1
|
|
system:capture_2
|
|
system:playback_1
|
|
system:playback_2
|
|
ffmpeg:input_1
|
|
metro:120_bpm
|
|
|
|
# Connect metro to the ffmpeg writable client.
|
|
$ jack_connect metro:120_bpm ffmpeg:input_1
|
|
</pre></td></tr></table>
|
|
|
|
<p>For more information read:
|
|
<a href="http://jackaudio.org/">http://jackaudio.org/</a>
|
|
</p>
|
|
<a name="lavfi"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-lavfi">16.7 lavfi</a></h2>
|
|
|
|
<p>Libavfilter input virtual device.
|
|
</p>
|
|
<p>This input device reads data from the open output pads of a libavfilter
|
|
filtergraph.
|
|
</p>
|
|
<p>For each filtergraph open output, the input device will create a
|
|
corresponding stream which is mapped to the generated output. Currently
|
|
only video data is supported. The filtergraph is specified through the
|
|
option ‘<samp>graph</samp>’.
|
|
</p>
|
|
<a name="Options"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Options">16.7.1 Options</a></h3>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>graph</samp>’</dt>
|
|
<dd><p>Specify the filtergraph to use as input. Each video open output must be
|
|
labelled by a unique string of the form "out<var>N</var>", where <var>N</var> is a
|
|
number starting from 0 corresponding to the mapped input stream
|
|
generated by the device.
|
|
The first unlabelled output is automatically assigned to the "out0"
|
|
label, but all the others need to be specified explicitly.
|
|
</p>
|
|
<p>If not specified defaults to the filename specified for the input
|
|
device.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Examples-3"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-3">16.7.2 Examples</a></h3>
|
|
|
|
<ul>
|
|
<li>
|
|
Create a color video stream and play it back with <code>ffplay</code>:
|
|
<table><tr><td> </td><td><pre class="example">ffplay -f lavfi -graph "color=pink [out0]" dummy
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
As the previous example, but use filename for specifying the graph
|
|
description, and omit the "out0" label:
|
|
<table><tr><td> </td><td><pre class="example">ffplay -f lavfi color=pink
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Create three different video test filtered sources and play them:
|
|
<table><tr><td> </td><td><pre class="example">ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Read an audio stream from a file using the amovie source and play it
|
|
back with <code>ffplay</code>:
|
|
<table><tr><td> </td><td><pre class="example">ffplay -f lavfi "amovie=test.wav"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Read an audio stream and a video stream and play it back with
|
|
<code>ffplay</code>:
|
|
<table><tr><td> </td><td><pre class="example">ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
|
|
</pre></td></tr></table>
|
|
|
|
</li></ul>
|
|
|
|
<a name="libdc1394"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-libdc1394">16.8 libdc1394</a></h2>
|
|
|
|
<p>IIDC1394 input device, based on libdc1394 and libraw1394.
|
|
</p>
|
|
<a name="openal"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-openal">16.9 openal</a></h2>
|
|
|
|
<p>The OpenAL input device provides audio capture on all systems with a
|
|
working OpenAL 1.1 implementation.
|
|
</p>
|
|
<p>To enable this input device during configuration, you need OpenAL
|
|
headers and libraries installed on your system, and need to configure
|
|
FFmpeg with <code>--enable-openal</code>.
|
|
</p>
|
|
<p>OpenAL headers and libraries should be provided as part of your OpenAL
|
|
implementation, or as an additional download (an SDK). Depending on your
|
|
installation you may need to specify additional flags via the
|
|
<code>--extra-cflags</code> and <code>--extra-ldflags</code> for allowing the build
|
|
system to locate the OpenAL headers and libraries.
|
|
</p>
|
|
<p>An incomplete list of OpenAL implementations follows:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> <strong>Creative</strong></dt>
|
|
<dd><p>The official Windows implementation, providing hardware acceleration
|
|
with supported devices and software fallback.
|
|
See <a href="http://openal.org/">http://openal.org/</a>.
|
|
</p></dd>
|
|
<dt> <strong>OpenAL Soft</strong></dt>
|
|
<dd><p>Portable, open source (LGPL) software implementation. Includes
|
|
backends for the most common sound APIs on the Windows, Linux,
|
|
Solaris, and BSD operating systems.
|
|
See <a href="http://kcat.strangesoft.net/openal.html">http://kcat.strangesoft.net/openal.html</a>.
|
|
</p></dd>
|
|
<dt> <strong>Apple</strong></dt>
|
|
<dd><p>OpenAL is part of Core Audio, the official Mac OS X Audio interface.
|
|
See <a href="http://developer.apple.com/technologies/mac/audio-and-video.html">http://developer.apple.com/technologies/mac/audio-and-video.html</a>
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>This device allows to capture from an audio input device handled
|
|
through OpenAL.
|
|
</p>
|
|
<p>You need to specify the name of the device to capture in the provided
|
|
filename. If the empty string is provided, the device will
|
|
automatically select the default device. You can get the list of the
|
|
supported devices by using the option <var>list_devices</var>.
|
|
</p>
|
|
<a name="Options-6"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Options-6">16.9.1 Options</a></h3>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>channels</samp>’</dt>
|
|
<dd><p>Set the number of channels in the captured audio. Only the values
|
|
‘<samp>1</samp>’ (monaural) and ‘<samp>2</samp>’ (stereo) are currently supported.
|
|
Defaults to ‘<samp>2</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sample_size</samp>’</dt>
|
|
<dd><p>Set the sample size (in bits) of the captured audio. Only the values
|
|
‘<samp>8</samp>’ and ‘<samp>16</samp>’ are currently supported. Defaults to
|
|
‘<samp>16</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sample_rate</samp>’</dt>
|
|
<dd><p>Set the sample rate (in Hz) of the captured audio.
|
|
Defaults to ‘<samp>44.1k</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>list_devices</samp>’</dt>
|
|
<dd><p>If set to ‘<samp>true</samp>’, print a list of devices and exit.
|
|
Defaults to ‘<samp>false</samp>’.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Examples-2"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-2">16.9.2 Examples</a></h3>
|
|
|
|
<p>Print the list of OpenAL supported devices and exit:
|
|
</p><table><tr><td> </td><td><pre class="example">$ ffmpeg -list_devices true -f openal -i dummy out.ogg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Capture from the OpenAL device ‘<tt>DR-BT101 via PulseAudio</tt>’:
|
|
</p><table><tr><td> </td><td><pre class="example">$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Capture from the default device (note the empty string ” as filename):
|
|
</p><table><tr><td> </td><td><pre class="example">$ ffmpeg -f openal -i '' out.ogg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Capture from two devices simultaneously, writing to two different files,
|
|
within the same <code>ffmpeg</code> command:
|
|
</p><table><tr><td> </td><td><pre class="example">$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
|
|
</pre></td></tr></table>
|
|
<p>Note: not all OpenAL implementations support multiple simultaneous capture -
|
|
try the latest OpenAL Soft if the above does not work.
|
|
</p>
|
|
<a name="oss"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-oss">16.10 oss</a></h2>
|
|
|
|
<p>Open Sound System input device.
|
|
</p>
|
|
<p>The filename to provide to the input device is the device node
|
|
representing the OSS input device, and is usually set to
|
|
‘<tt>/dev/dsp</tt>’.
|
|
</p>
|
|
<p>For example to grab from ‘<tt>/dev/dsp</tt>’ using <code>ffmpeg</code> use the
|
|
command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
|
|
</pre></td></tr></table>
|
|
|
|
<p>For more information about OSS see:
|
|
<a href="http://manuals.opensound.com/usersguide/dsp.html">http://manuals.opensound.com/usersguide/dsp.html</a>
|
|
</p>
|
|
<a name="pulse"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-pulse">16.11 pulse</a></h2>
|
|
|
|
<p>pulseaudio input device.
|
|
</p>
|
|
<p>To enable this input device during configuration you need libpulse-simple
|
|
installed in your system.
|
|
</p>
|
|
<p>The filename to provide to the input device is a source device or the
|
|
string "default"
|
|
</p>
|
|
<p>To list the pulse source devices and their properties you can invoke
|
|
the command <code>pactl list sources</code>.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -f pulse -i default /tmp/pulse.wav
|
|
</pre></td></tr></table>
|
|
|
|
<a name="server-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-server-AVOption">16.11.1 <var>server</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-server <var>server name</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Connects to a specific server.
|
|
</p>
|
|
<a name="name-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-name-AVOption">16.11.2 <var>name</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-name <var>application name</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Specify the application name pulse will use when showing active clients,
|
|
by default it is the LIBAVFORMAT_IDENT string
|
|
</p>
|
|
<a name="stream_005fname-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-stream_005fname-AVOption">16.11.3 <var>stream_name</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-stream_name <var>stream name</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Specify the stream name pulse will use when showing active streams,
|
|
by default it is "record"
|
|
</p>
|
|
<a name="sample_005frate-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-sample_005frate-AVOption">16.11.4 <var>sample_rate</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-sample_rate <var>samplerate</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Specify the samplerate in Hz, by default 48kHz is used.
|
|
</p>
|
|
<a name="channels-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-channels-AVOption">16.11.5 <var>channels</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-channels <var>N</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Specify the channels in use, by default 2 (stereo) is set.
|
|
</p>
|
|
<a name="frame_005fsize-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-frame_005fsize-AVOption">16.11.6 <var>frame_size</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-frame_size <var>bytes</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Specify the number of byte per frame, by default it is set to 1024.
|
|
</p>
|
|
<a name="fragment_005fsize-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-fragment_005fsize-AVOption">16.11.7 <var>fragment_size</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-fragment_size <var>bytes</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Specify the minimal buffering fragment in pulseaudio, it will affect the
|
|
audio latency. By default it is unset.
|
|
</p>
|
|
<a name="sndio"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-sndio">16.12 sndio</a></h2>
|
|
|
|
<p>sndio input device.
|
|
</p>
|
|
<p>To enable this input device during configuration you need libsndio
|
|
installed on your system.
|
|
</p>
|
|
<p>The filename to provide to the input device is the device node
|
|
representing the sndio input device, and is usually set to
|
|
‘<tt>/dev/audio0</tt>’.
|
|
</p>
|
|
<p>For example to grab from ‘<tt>/dev/audio0</tt>’ using <code>ffmpeg</code> use the
|
|
command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
|
|
</pre></td></tr></table>
|
|
|
|
<a name="video4linux-and-video4linux2"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-video4linux-and-video4linux2">16.13 video4linux and video4linux2</a></h2>
|
|
|
|
<p>Video4Linux and Video4Linux2 input video devices.
|
|
</p>
|
|
<p>The name of the device to grab is a file device node, usually Linux
|
|
systems tend to automatically create such nodes when the device
|
|
(e.g. an USB webcam) is plugged into the system, and has a name of the
|
|
kind ‘<tt>/dev/video<var>N</var></tt>’, where <var>N</var> is a number associated to
|
|
the device.
|
|
</p>
|
|
<p>Video4Linux and Video4Linux2 devices only support a limited set of
|
|
<var>width</var>x<var>height</var> sizes and framerates. You can check which are
|
|
supported for example with the command <code>dov4l</code> for Video4Linux
|
|
devices and using <code>-list_formats all</code> for Video4Linux2 devices.
|
|
</p>
|
|
<p>If the size for the device is set to 0x0, the input device will
|
|
try to auto-detect the size to use.
|
|
Only for the video4linux2 device, if the frame rate is set to 0/0 the
|
|
input device will use the frame rate value already set in the driver.
|
|
</p>
|
|
<p>Video4Linux support is deprecated since Linux 2.6.30, and will be
|
|
dropped in later versions.
|
|
</p>
|
|
<p>Note that if FFmpeg is build with v4l-utils support ("–enable-libv4l2"
|
|
option), it will always be used.
|
|
</p>
|
|
<p>Follow some usage examples of the video4linux devices with the ff*
|
|
tools.
|
|
</p><table><tr><td> </td><td><pre class="example"># Grab and show the input of a video4linux device, frame rate is set
|
|
# to the default of 25/1.
|
|
ffplay -s 320x240 -f video4linux /dev/video0
|
|
|
|
# Grab and show the input of a video4linux2 device, auto-adjust size.
|
|
ffplay -f video4linux2 /dev/video0
|
|
|
|
# Grab and record the input of a video4linux2 device, auto-adjust size,
|
|
# frame rate value defaults to 0/0 so it is read from the video4linux2
|
|
# driver.
|
|
ffmpeg -f video4linux2 -i /dev/video0 out.mpeg
|
|
</pre></td></tr></table>
|
|
|
|
<p>"v4l" and "v4l2" can be used as aliases for the respective "video4linux" and
|
|
"video4linux2".
|
|
</p>
|
|
<a name="vfwcap"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-vfwcap">16.14 vfwcap</a></h2>
|
|
|
|
<p>VfW (Video for Windows) capture input device.
|
|
</p>
|
|
<p>The filename passed as input is the capture driver number, ranging from
|
|
0 to 9. You may use "list" as filename to print a list of drivers. Any
|
|
other filename will be interpreted as device number 0.
|
|
</p>
|
|
<a name="x11grab"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-x11grab">16.15 x11grab</a></h2>
|
|
|
|
<p>X11 video input device.
|
|
</p>
|
|
<p>This device allows to capture a region of an X11 display.
|
|
</p>
|
|
<p>The filename passed as input has the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example">[<var>hostname</var>]:<var>display_number</var>.<var>screen_number</var>[+<var>x_offset</var>,<var>y_offset</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p><var>hostname</var>:<var>display_number</var>.<var>screen_number</var> specifies the
|
|
X11 display name of the screen to grab from. <var>hostname</var> can be
|
|
omitted, and defaults to "localhost". The environment variable
|
|
<code>DISPLAY</code> contains the default display name.
|
|
</p>
|
|
<p><var>x_offset</var> and <var>y_offset</var> specify the offsets of the grabbed
|
|
area with respect to the top-left border of the X11 screen. They
|
|
default to 0.
|
|
</p>
|
|
<p>Check the X11 documentation (e.g. man X) for more detailed information.
|
|
</p>
|
|
<p>Use the <code>dpyinfo</code> program for getting basic information about the
|
|
properties of your X11 display (e.g. grep for "name" or "dimensions").
|
|
</p>
|
|
<p>For example to grab from ‘<tt>:0.0</tt>’ using <code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg
|
|
|
|
# Grab at position 10,20.
|
|
ffmpeg -f x11grab -r 25 -s cif -i :0.0+10,20 out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<a name="follow_005fmouse-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-follow_005fmouse-AVOption">16.15.1 <var>follow_mouse</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-follow_mouse centered|<var>PIXELS</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>When it is specified with "centered", the grabbing region follows the mouse
|
|
pointer and keeps the pointer at the center of region; otherwise, the region
|
|
follows only when the mouse pointer reaches within <var>PIXELS</var> (greater than
|
|
zero) to the edge of region.
|
|
</p>
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f x11grab -follow_mouse centered -r 25 -s cif -i :0.0 out.mpg
|
|
|
|
# Follows only when the mouse pointer reaches within 100 pixels to edge
|
|
ffmpeg -f x11grab -follow_mouse 100 -r 25 -s cif -i :0.0 out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<a name="show_005fregion-AVOption"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-show_005fregion-AVOption">16.15.2 <var>show_region</var> AVOption</a></h3>
|
|
|
|
<p>The syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">-show_region 1
|
|
</pre></td></tr></table>
|
|
|
|
<p>If <var>show_region</var> AVOption is specified with <var>1</var>, then the grabbing
|
|
region will be indicated on screen. With this option, it’s easy to know what is
|
|
being grabbed if only a portion of the screen is grabbed.
|
|
</p>
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f x11grab -show_region 1 -r 25 -s cif -i :0.0+10,20 out.mpg
|
|
|
|
# With follow_mouse
|
|
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -r 25 -s cif -i :0.0 out.mpg
|
|
</pre></td></tr></table>
|
|
|
|
<a name="Output-Devices"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Output-Devices">17. Output Devices</a></h1>
|
|
|
|
<p>Output devices are configured elements in FFmpeg which allow to write
|
|
multimedia data to an output device attached to your system.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported output devices
|
|
are enabled by default. You can list all available ones using the
|
|
configure option "–list-outdevs".
|
|
</p>
|
|
<p>You can disable all the output devices using the configure option
|
|
"–disable-outdevs", and selectively enable an output device using the
|
|
option "–enable-outdev=<var>OUTDEV</var>", or you can disable a particular
|
|
input device using the option "–disable-outdev=<var>OUTDEV</var>".
|
|
</p>
|
|
<p>The option "-formats" of the ff* tools will display the list of
|
|
enabled output devices (amongst the muxers).
|
|
</p>
|
|
<p>A description of the currently available output devices follows.
|
|
</p>
|
|
<a name="alsa"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-alsa">17.1 alsa</a></h2>
|
|
|
|
<p>ALSA (Advanced Linux Sound Architecture) output device.
|
|
</p>
|
|
<a name="oss-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-oss-1">17.2 oss</a></h2>
|
|
|
|
<p>OSS (Open Sound System) output device.
|
|
</p>
|
|
<a name="sdl"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-sdl">17.3 sdl</a></h2>
|
|
|
|
<p>SDL (Simple DirectMedia Layer) output device.
|
|
</p>
|
|
<p>This output devices allows to show a video stream in an SDL
|
|
window. Only one SDL window is allowed per application, so you can
|
|
have only one instance of this output device in an application.
|
|
</p>
|
|
<p>To enable this output device you need libsdl installed on your system
|
|
when configuring your build.
|
|
</p>
|
|
<p>For more information about SDL, check:
|
|
<a href="http://www.libsdl.org/">http://www.libsdl.org/</a>
|
|
</p>
|
|
<a name="Options-3"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Options-3">17.3.1 Options</a></h3>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>window_title</samp>’</dt>
|
|
<dd><p>Set the SDL window title, if not specified default to the filename
|
|
specified for the output device.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>icon_title</samp>’</dt>
|
|
<dd><p>Set the name of the iconified SDL window, if not specified it is set
|
|
to the same value of <var>window_title</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>window_size</samp>’</dt>
|
|
<dd><p>Set the SDL window size, can be a string of the form
|
|
<var>width</var>x<var>height</var> or a video size abbreviation.
|
|
If not specified it defaults to the size of the input video.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Examples-6"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-6">17.3.2 Examples</a></h3>
|
|
|
|
<p>The following command shows the <code>ffmpeg</code> output is an
|
|
SDL window, forcing its size to the qcif format:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
|
|
</pre></td></tr></table>
|
|
|
|
<a name="sndio-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-sndio-1">17.4 sndio</a></h2>
|
|
|
|
<p>sndio audio output device.
|
|
</p>
|
|
<a name="Protocols"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Protocols">18. Protocols</a></h1>
|
|
|
|
<p>Protocols are configured elements in FFmpeg which allow to access
|
|
resources which require the use of a particular protocol.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported protocols are
|
|
enabled by default. You can list all available ones using the
|
|
configure option "–list-protocols".
|
|
</p>
|
|
<p>You can disable all the protocols using the configure option
|
|
"–disable-protocols", and selectively enable a protocol using the
|
|
option "–enable-protocol=<var>PROTOCOL</var>", or you can disable a
|
|
particular protocol using the option
|
|
"–disable-protocol=<var>PROTOCOL</var>".
|
|
</p>
|
|
<p>The option "-protocols" of the ff* tools will display the list of
|
|
supported protocols.
|
|
</p>
|
|
<p>A description of the currently available protocols follows.
|
|
</p>
|
|
<a name="applehttp-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-applehttp-1">18.1 applehttp</a></h2>
|
|
|
|
<p>Read Apple HTTP Live Streaming compliant segmented stream as
|
|
a uniform one. The M3U8 playlists describing the segments can be
|
|
remote HTTP resources or local files, accessed using the standard
|
|
file protocol.
|
|
HTTP is default, specific protocol can be declared by specifying
|
|
"+<var>proto</var>" after the applehttp URI scheme name, where <var>proto</var>
|
|
is either "file" or "http".
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">applehttp://host/path/to/remote/resource.m3u8
|
|
applehttp+http://host/path/to/remote/resource.m3u8
|
|
applehttp+file://path/to/local/resource.m3u8
|
|
</pre></td></tr></table>
|
|
|
|
<a name="concat"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-concat">18.2 concat</a></h2>
|
|
|
|
<p>Physical concatenation protocol.
|
|
</p>
|
|
<p>Allow to read and seek from many resource in sequence as if they were
|
|
a unique resource.
|
|
</p>
|
|
<p>A URL accepted by this protocol has the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example">concat:<var>URL1</var>|<var>URL2</var>|...|<var>URLN</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>where <var>URL1</var>, <var>URL2</var>, ..., <var>URLN</var> are the urls of the
|
|
resource to be concatenated, each one possibly specifying a distinct
|
|
protocol.
|
|
</p>
|
|
<p>For example to read a sequence of files ‘<tt>split1.mpeg</tt>’,
|
|
‘<tt>split2.mpeg</tt>’, ‘<tt>split3.mpeg</tt>’ with <code>ffplay</code> use the
|
|
command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that you may need to escape the character "|" which is special for
|
|
many shells.
|
|
</p>
|
|
<a name="file"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-file">18.3 file</a></h2>
|
|
|
|
<p>File access protocol.
|
|
</p>
|
|
<p>Allow to read from or read to a file.
|
|
</p>
|
|
<p>For example to read from a file ‘<tt>input.mpeg</tt>’ with <code>ffmpeg</code>
|
|
use the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i file:input.mpeg output.mpeg
|
|
</pre></td></tr></table>
|
|
|
|
<p>The ff* tools default to the file protocol, that is a resource
|
|
specified with the name "FILE.mpeg" is interpreted as the URL
|
|
"file:FILE.mpeg".
|
|
</p>
|
|
<a name="gopher"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-gopher">18.4 gopher</a></h2>
|
|
|
|
<p>Gopher protocol.
|
|
</p>
|
|
<a name="http"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-http">18.5 http</a></h2>
|
|
|
|
<p>HTTP (Hyper Text Transfer Protocol).
|
|
</p>
|
|
<a name="mmst"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mmst">18.6 mmst</a></h2>
|
|
|
|
<p>MMS (Microsoft Media Server) protocol over TCP.
|
|
</p>
|
|
<a name="mmsh"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mmsh">18.7 mmsh</a></h2>
|
|
|
|
<p>MMS (Microsoft Media Server) protocol over HTTP.
|
|
</p>
|
|
<p>The required syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">mmsh://<var>server</var>[:<var>port</var>][/<var>app</var>][/<var>playpath</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<a name="md5"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-md5">18.8 md5</a></h2>
|
|
|
|
<p>MD5 output protocol.
|
|
</p>
|
|
<p>Computes the MD5 hash of the data to be written, and on close writes
|
|
this to the designated output or stdout if none is specified. It can
|
|
be used to test muxers without writing an actual file.
|
|
</p>
|
|
<p>Some examples follow.
|
|
</p><table><tr><td> </td><td><pre class="example"># Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
|
|
ffmpeg -i input.flv -f avi -y md5:output.avi.md5
|
|
|
|
# Write the MD5 hash of the encoded AVI file to stdout.
|
|
ffmpeg -i input.flv -f avi -y md5:
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that some formats (typically MOV) require the output protocol to
|
|
be seekable, so they will fail with the MD5 output protocol.
|
|
</p>
|
|
<a name="pipe"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-pipe">18.9 pipe</a></h2>
|
|
|
|
<p>UNIX pipe access protocol.
|
|
</p>
|
|
<p>Allow to read and write from UNIX pipes.
|
|
</p>
|
|
<p>The accepted syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">pipe:[<var>number</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p><var>number</var> is the number corresponding to the file descriptor of the
|
|
pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If <var>number</var>
|
|
is not specified, by default the stdout file descriptor will be used
|
|
for writing, stdin for reading.
|
|
</p>
|
|
<p>For example to read from stdin with <code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">cat test.wav | ffmpeg -i pipe:0
|
|
# ...this is the same as...
|
|
cat test.wav | ffmpeg -i pipe:
|
|
</pre></td></tr></table>
|
|
|
|
<p>For writing to stdout with <code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
|
|
# ...this is the same as...
|
|
ffmpeg -i test.wav -f avi pipe: | cat > test.avi
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that some formats (typically MOV), require the output protocol to
|
|
be seekable, so they will fail with the pipe output protocol.
|
|
</p>
|
|
<a name="rtmp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-rtmp">18.10 rtmp</a></h2>
|
|
|
|
<p>Real-Time Messaging Protocol.
|
|
</p>
|
|
<p>The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
|
|
content across a TCP/IP network.
|
|
</p>
|
|
<p>The required syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">rtmp://<var>server</var>[:<var>port</var>][/<var>app</var>][/<var>playpath</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p>The accepted parameters are:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>server</samp>’</dt>
|
|
<dd><p>The address of the RTMP server.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>port</samp>’</dt>
|
|
<dd><p>The number of the TCP port to use (by default is 1935).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>app</samp>’</dt>
|
|
<dd><p>It is the name of the application to access. It usually corresponds to
|
|
the path where the application is installed on the RTMP server
|
|
(e.g. ‘<tt>/ondemand/</tt>’, ‘<tt>/flash/live/</tt>’, etc.).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>playpath</samp>’</dt>
|
|
<dd><p>It is the path or name of the resource to play with reference to the
|
|
application specified in <var>app</var>, may be prefixed by "mp4:".
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>For example to read with <code>ffplay</code> a multimedia resource named
|
|
"sample" from the application "vod" from an RTMP server "myserver":
|
|
</p><table><tr><td> </td><td><pre class="example">ffplay rtmp://myserver/vod/sample
|
|
</pre></td></tr></table>
|
|
|
|
<a name="rtmp_002c-rtmpe_002c-rtmps_002c-rtmpt_002c-rtmpte"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-rtmp_002c-rtmpe_002c-rtmps_002c-rtmpt_002c-rtmpte">18.11 rtmp, rtmpe, rtmps, rtmpt, rtmpte</a></h2>
|
|
|
|
<p>Real-Time Messaging Protocol and its variants supported through
|
|
librtmp.
|
|
</p>
|
|
<p>Requires the presence of the librtmp headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
"–enable-librtmp". If enabled this will replace the native RTMP
|
|
protocol.
|
|
</p>
|
|
<p>This protocol provides most client functions and a few server
|
|
functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
|
|
encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
|
|
variants of these encrypted types (RTMPTE, RTMPTS).
|
|
</p>
|
|
<p>The required syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example"><var>rtmp_proto</var>://<var>server</var>[:<var>port</var>][/<var>app</var>][/<var>playpath</var>] <var>options</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>where <var>rtmp_proto</var> is one of the strings "rtmp", "rtmpt", "rtmpe",
|
|
"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
|
|
<var>server</var>, <var>port</var>, <var>app</var> and <var>playpath</var> have the same
|
|
meaning as specified for the RTMP native protocol.
|
|
<var>options</var> contains a list of space-separated options of the form
|
|
<var>key</var>=<var>val</var>.
|
|
</p>
|
|
<p>See the librtmp manual page (man 3 librtmp) for more information.
|
|
</p>
|
|
<p>For example, to stream a file in real-time to an RTMP server using
|
|
<code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
|
|
</pre></td></tr></table>
|
|
|
|
<p>To play the same stream using <code>ffplay</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffplay "rtmp://myserver/live/mystream live=1"
|
|
</pre></td></tr></table>
|
|
|
|
<a name="rtp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-rtp">18.12 rtp</a></h2>
|
|
|
|
<p>Real-Time Protocol.
|
|
</p>
|
|
<a name="rtsp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-rtsp">18.13 rtsp</a></h2>
|
|
|
|
<p>RTSP is not technically a protocol handler in libavformat, it is a demuxer
|
|
and muxer. The demuxer supports both normal RTSP (with data transferred
|
|
over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
|
|
data transferred over RDT).
|
|
</p>
|
|
<p>The muxer can be used to send a stream using RTSP ANNOUNCE to a server
|
|
supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
|
|
<a href="http://github.com/revmischa/rtsp-server">RTSP server</a>).
|
|
</p>
|
|
<p>The required syntax for a RTSP url is:
|
|
</p><table><tr><td> </td><td><pre class="example">rtsp://<var>hostname</var>[:<var>port</var>]/<var>path</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>The following options (set on the <code>ffmpeg</code>/<code>ffplay</code> command
|
|
line, or set in code via <code>AVOption</code>s or in <code>avformat_open_input</code>),
|
|
are supported:
|
|
</p>
|
|
<p>Flags for <code>rtsp_transport</code>:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>udp</samp>’</dt>
|
|
<dd><p>Use UDP as lower transport protocol.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>tcp</samp>’</dt>
|
|
<dd><p>Use TCP (interleaving within the RTSP control channel) as lower
|
|
transport protocol.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>udp_multicast</samp>’</dt>
|
|
<dd><p>Use UDP multicast as lower transport protocol.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>http</samp>’</dt>
|
|
<dd><p>Use HTTP tunneling as lower transport protocol, which is useful for
|
|
passing proxies.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Multiple lower transport protocols may be specified, in that case they are
|
|
tried one at a time (if the setup of one fails, the next one is tried).
|
|
For the muxer, only the <code>tcp</code> and <code>udp</code> options are supported.
|
|
</p>
|
|
<p>Flags for <code>rtsp_flags</code>:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>filter_src</samp>’</dt>
|
|
<dd><p>Accept packets only from negotiated peer address and port.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>When receiving data over UDP, the demuxer tries to reorder received packets
|
|
(since they may arrive out of order, or packets may get lost totally). In
|
|
order for this to be enabled, a maximum delay must be specified in the
|
|
<code>max_delay</code> field of AVFormatContext.
|
|
</p>
|
|
<p>When watching multi-bitrate Real-RTSP streams with <code>ffplay</code>, the
|
|
streams to display can be chosen with <code>-vst</code> <var>n</var> and
|
|
<code>-ast</code> <var>n</var> for video and audio respectively, and can be switched
|
|
on the fly by pressing <code>v</code> and <code>a</code>.
|
|
</p>
|
|
<p>Example command lines:
|
|
</p>
|
|
<p>To watch a stream over UDP, with a max reordering delay of 0.5 seconds:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
|
|
</pre></td></tr></table>
|
|
|
|
<p>To watch a stream tunneled over HTTP:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffplay -rtsp_transport http rtsp://server/video.mp4
|
|
</pre></td></tr></table>
|
|
|
|
<p>To send a stream in realtime to a RTSP server, for others to watch:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -re -i <var>input</var> -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
|
|
</pre></td></tr></table>
|
|
|
|
<a name="sap"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-sap">18.14 sap</a></h2>
|
|
|
|
<p>Session Announcement Protocol (RFC 2974). This is not technically a
|
|
protocol handler in libavformat, it is a muxer and demuxer.
|
|
It is used for signalling of RTP streams, by announcing the SDP for the
|
|
streams regularly on a separate port.
|
|
</p>
|
|
<a name="Muxer"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Muxer">18.14.1 Muxer</a></h3>
|
|
|
|
<p>The syntax for a SAP url given to the muxer is:
|
|
</p><table><tr><td> </td><td><pre class="example">sap://<var>destination</var>[:<var>port</var>][?<var>options</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p>The RTP packets are sent to <var>destination</var> on port <var>port</var>,
|
|
or to port 5004 if no port is specified.
|
|
<var>options</var> is a <code>&</code>-separated list. The following options
|
|
are supported:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>announce_addr=<var>address</var></samp>’</dt>
|
|
<dd><p>Specify the destination IP address for sending the announcements to.
|
|
If omitted, the announcements are sent to the commonly used SAP
|
|
announcement multicast address 224.2.127.254 (sap.mcast.net), or
|
|
ff0e::2:7ffe if <var>destination</var> is an IPv6 address.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>announce_port=<var>port</var></samp>’</dt>
|
|
<dd><p>Specify the port to send the announcements on, defaults to
|
|
9875 if not specified.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ttl=<var>ttl</var></samp>’</dt>
|
|
<dd><p>Specify the time to live value for the announcements and RTP packets,
|
|
defaults to 255.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>same_port=<var>0|1</var></samp>’</dt>
|
|
<dd><p>If set to 1, send all RTP streams on the same port pair. If zero (the
|
|
default), all streams are sent on unique ports, with each stream on a
|
|
port 2 numbers higher than the previous.
|
|
VLC/Live555 requires this to be set to 1, to be able to receive the stream.
|
|
The RTP stack in libavformat for receiving requires all streams to be sent
|
|
on unique ports.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Example command lines follow.
|
|
</p>
|
|
<p>To broadcast a stream on the local subnet, for watching in VLC:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -re -i <var>input</var> -f sap sap://224.0.0.255?same_port=1
|
|
</pre></td></tr></table>
|
|
|
|
<p>Similarly, for watching in <code>ffplay</code>:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -re -i <var>input</var> -f sap sap://224.0.0.255
|
|
</pre></td></tr></table>
|
|
|
|
<p>And for watching in <code>ffplay</code>, over IPv6:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -re -i <var>input</var> -f sap sap://[ff0e::1:2:3:4]
|
|
</pre></td></tr></table>
|
|
|
|
<a name="Demuxer"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Demuxer">18.14.2 Demuxer</a></h3>
|
|
|
|
<p>The syntax for a SAP url given to the demuxer is:
|
|
</p><table><tr><td> </td><td><pre class="example">sap://[<var>address</var>][:<var>port</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p><var>address</var> is the multicast address to listen for announcements on,
|
|
if omitted, the default 224.2.127.254 (sap.mcast.net) is used. <var>port</var>
|
|
is the port that is listened on, 9875 if omitted.
|
|
</p>
|
|
<p>The demuxers listens for announcements on the given address and port.
|
|
Once an announcement is received, it tries to receive that particular stream.
|
|
</p>
|
|
<p>Example command lines follow.
|
|
</p>
|
|
<p>To play back the first stream announced on the normal SAP multicast address:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffplay sap://
|
|
</pre></td></tr></table>
|
|
|
|
<p>To play back the first stream announced on one the default IPv6 SAP multicast address:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffplay sap://[ff0e::2:7ffe]
|
|
</pre></td></tr></table>
|
|
|
|
<a name="tcp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-tcp">18.15 tcp</a></h2>
|
|
|
|
<p>Trasmission Control Protocol.
|
|
</p>
|
|
<p>The required syntax for a TCP url is:
|
|
</p><table><tr><td> </td><td><pre class="example">tcp://<var>hostname</var>:<var>port</var>[?<var>options</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>listen</samp>’</dt>
|
|
<dd><p>Listen for an incoming connection
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i <var>input</var> -f <var>format</var> tcp://<var>hostname</var>:<var>port</var>?listen
|
|
ffplay tcp://<var>hostname</var>:<var>port</var>
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="udp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-udp">18.16 udp</a></h2>
|
|
|
|
<p>User Datagram Protocol.
|
|
</p>
|
|
<p>The required syntax for a UDP url is:
|
|
</p><table><tr><td> </td><td><pre class="example">udp://<var>hostname</var>:<var>port</var>[?<var>options</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p><var>options</var> contains a list of &-seperated options of the form <var>key</var>=<var>val</var>.
|
|
Follow the list of supported options.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>buffer_size=<var>size</var></samp>’</dt>
|
|
<dd><p>set the UDP buffer size in bytes
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>localport=<var>port</var></samp>’</dt>
|
|
<dd><p>override the local UDP port to bind with
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>localaddr=<var>addr</var></samp>’</dt>
|
|
<dd><p>Choose the local IP address. This is useful e.g. if sending multicast
|
|
and the host has multiple interfaces, where the user can choose
|
|
which interface to send on by specifying the IP address of that interface.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pkt_size=<var>size</var></samp>’</dt>
|
|
<dd><p>set the size in bytes of UDP packets
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>reuse=<var>1|0</var></samp>’</dt>
|
|
<dd><p>explicitly allow or disallow reusing UDP sockets
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ttl=<var>ttl</var></samp>’</dt>
|
|
<dd><p>set the time to live value (for multicast only)
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>connect=<var>1|0</var></samp>’</dt>
|
|
<dd><p>Initialize the UDP socket with <code>connect()</code>. In this case, the
|
|
destination address can’t be changed with ff_udp_set_remote_url later.
|
|
If the destination address isn’t known at the start, this option can
|
|
be specified in ff_udp_set_remote_url, too.
|
|
This allows finding out the source address for the packets with getsockname,
|
|
and makes writes return with AVERROR(ECONNREFUSED) if "destination
|
|
unreachable" is received.
|
|
For receiving, this gives the benefit of only receiving packets from
|
|
the specified peer address/port.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Some usage examples of the udp protocol with <code>ffmpeg</code> follow.
|
|
</p>
|
|
<p>To stream over UDP to a remote endpoint:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i <var>input</var> -f <var>format</var> udp://<var>hostname</var>:<var>port</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>To stream in mpegts format over UDP using 188 sized UDP packets, using a large input buffer:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i <var>input</var> -f mpegts udp://<var>hostname</var>:<var>port</var>?pkt_size=188&buffer_size=65535
|
|
</pre></td></tr></table>
|
|
|
|
<p>To receive over UDP from a remote endpoint:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i udp://[<var>multicast-address</var>]:<var>port</var>
|
|
</pre></td></tr></table>
|
|
|
|
<a name="Bitstream-Filters"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Bitstream-Filters">19. Bitstream Filters</a></h1>
|
|
|
|
<p>When you configure your FFmpeg build, all the supported bitstream
|
|
filters are enabled by default. You can list all available ones using
|
|
the configure option <code>--list-bsfs</code>.
|
|
</p>
|
|
<p>You can disable all the bitstream filters using the configure option
|
|
<code>--disable-bsfs</code>, and selectively enable any bitstream filter using
|
|
the option <code>--enable-bsf=BSF</code>, or you can disable a particular
|
|
bitstream filter using the option <code>--disable-bsf=BSF</code>.
|
|
</p>
|
|
<p>The option <code>-bsfs</code> of the ff* tools will display the list of
|
|
all the supported bitstream filters included in your build.
|
|
</p>
|
|
<p>Below is a description of the currently available bitstream filters.
|
|
</p>
|
|
<a name="aac_005fadtstoasc"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-aac_005fadtstoasc">19.1 aac_adtstoasc</a></h2>
|
|
|
|
<a name="chomp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-chomp">19.2 chomp</a></h2>
|
|
|
|
<a name="dump_005fextradata"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-dump_005fextradata">19.3 dump_extradata</a></h2>
|
|
|
|
<a name="h264_005fmp4toannexb"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-h264_005fmp4toannexb">19.4 h264_mp4toannexb</a></h2>
|
|
|
|
<p>Convert an H.264 bitstream from length prefixed mode to start code
|
|
prefixed mode (as defined in the Annex B of the ITU-T H.264
|
|
specification).
|
|
</p>
|
|
<p>This is required by some streaming formats, typically the MPEG-2
|
|
transport stream format ("mpegts").
|
|
</p>
|
|
<p>For example to remux an MP4 file containing an H.264 stream to mpegts
|
|
format with <code>ffmpeg</code>, you can use the command:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
|
|
</pre></td></tr></table>
|
|
|
|
<a name="imx_005fdump_005fheader"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-imx_005fdump_005fheader">19.5 imx_dump_header</a></h2>
|
|
|
|
<a name="mjpeg2jpeg"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mjpeg2jpeg">19.6 mjpeg2jpeg</a></h2>
|
|
|
|
<p>Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
|
|
</p>
|
|
<p>MJPEG is a video codec wherein each video frame is essentially a
|
|
JPEG image. The individual frames can be extracted without loss,
|
|
e.g. by
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
|
|
</pre></td></tr></table>
|
|
|
|
<p>Unfortunately, these chunks are incomplete JPEG images, because
|
|
they lack the DHT segment required for decoding. Quoting from
|
|
<a href="http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml">http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml</a>:
|
|
</p>
|
|
<p>Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
|
|
commented that "MJPEG, or at least the MJPEG in AVIs having the
|
|
MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
|
|
Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
|
|
and it must use basic Huffman encoding, not arithmetic or
|
|
progressive. . . . You can indeed extract the MJPEG frames and
|
|
decode them with a regular JPEG decoder, but you have to prepend
|
|
the DHT segment to them, or else the decoder won’t have any idea
|
|
how to decompress the data. The exact table necessary is given in
|
|
the OpenDML spec."
|
|
</p>
|
|
<p>This bitstream filter patches the header of frames extracted from an MJPEG
|
|
stream (carrying the AVI1 header ID and lacking a DHT segment) to
|
|
produce fully qualified JPEG images.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i mjpeg-movie.avi -c:v copy -vbsf mjpeg2jpeg frame_%d.jpg
|
|
exiftran -i -9 frame*.jpg
|
|
ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
|
|
</pre></td></tr></table>
|
|
|
|
<a name="mjpega_005fdump_005fheader"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mjpega_005fdump_005fheader">19.7 mjpega_dump_header</a></h2>
|
|
|
|
<a name="movsub"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-movsub">19.8 movsub</a></h2>
|
|
|
|
<a name="mp3_005fheader_005fcompress"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mp3_005fheader_005fcompress">19.9 mp3_header_compress</a></h2>
|
|
|
|
<a name="mp3_005fheader_005fdecompress"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mp3_005fheader_005fdecompress">19.10 mp3_header_decompress</a></h2>
|
|
|
|
<a name="noise"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-noise">19.11 noise</a></h2>
|
|
|
|
<a name="remove_005fextradata"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-remove_005fextradata">19.12 remove_extradata</a></h2>
|
|
|
|
<a name="Filtergraph-description"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Filtergraph-description">20. Filtergraph description</a></h1>
|
|
|
|
<p>A filtergraph is a directed graph of connected filters. It can contain
|
|
cycles, and there can be multiple links between a pair of
|
|
filters. Each link has one input pad on one side connecting it to one
|
|
filter from which it takes its input, and one output pad on the other
|
|
side connecting it to the one filter accepting its output.
|
|
</p>
|
|
<p>Each filter in a filtergraph is an instance of a filter class
|
|
registered in the application, which defines the features and the
|
|
number of input and output pads of the filter.
|
|
</p>
|
|
<p>A filter with no input pads is called a "source", a filter with no
|
|
output pads is called a "sink".
|
|
</p>
|
|
<a name="Filtergraph-syntax"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-Filtergraph-syntax">20.1 Filtergraph syntax</a></h2>
|
|
|
|
<p>A filtergraph can be represented using a textual representation, which
|
|
is recognized by the <code>-vf</code> option of the ff*
|
|
tools, and by the <code>avfilter_graph_parse()</code> function defined in
|
|
‘<tt>libavfilter/avfiltergraph.h</tt>’.
|
|
</p>
|
|
<p>A filterchain consists of a sequence of connected filters, each one
|
|
connected to the previous one in the sequence. A filterchain is
|
|
represented by a list of ","-separated filter descriptions.
|
|
</p>
|
|
<p>A filtergraph consists of a sequence of filterchains. A sequence of
|
|
filterchains is represented by a list of ";"-separated filterchain
|
|
descriptions.
|
|
</p>
|
|
<p>A filter is represented by a string of the form:
|
|
[<var>in_link_1</var>]...[<var>in_link_N</var>]<var>filter_name</var>=<var>arguments</var>[<var>out_link_1</var>]...[<var>out_link_M</var>]
|
|
</p>
|
|
<p><var>filter_name</var> is the name of the filter class of which the
|
|
described filter is an instance of, and has to be the name of one of
|
|
the filter classes registered in the program.
|
|
The name of the filter class is optionally followed by a string
|
|
"=<var>arguments</var>".
|
|
</p>
|
|
<p><var>arguments</var> is a string which contains the parameters used to
|
|
initialize the filter instance, and are described in the filter
|
|
descriptions below.
|
|
</p>
|
|
<p>The list of arguments can be quoted using the character "’" as initial
|
|
and ending mark, and the character ’\’ for escaping the characters
|
|
within the quoted text; otherwise the argument string is considered
|
|
terminated when the next special character (belonging to the set
|
|
"[]=;,") is encountered.
|
|
</p>
|
|
<p>The name and arguments of the filter are optionally preceded and
|
|
followed by a list of link labels.
|
|
A link label allows to name a link and associate it to a filter output
|
|
or input pad. The preceding labels <var>in_link_1</var>
|
|
... <var>in_link_N</var>, are associated to the filter input pads,
|
|
the following labels <var>out_link_1</var> ... <var>out_link_M</var>, are
|
|
associated to the output pads.
|
|
</p>
|
|
<p>When two link labels with the same name are found in the
|
|
filtergraph, a link between the corresponding input and output pad is
|
|
created.
|
|
</p>
|
|
<p>If an output pad is not labelled, it is linked by default to the first
|
|
unlabelled input pad of the next filter in the filterchain.
|
|
For example in the filterchain:
|
|
</p><table><tr><td> </td><td><pre class="example">nullsrc, split[L1], [L2]overlay, nullsink
|
|
</pre></td></tr></table>
|
|
<p>the split filter instance has two output pads, and the overlay filter
|
|
instance two input pads. The first output pad of split is labelled
|
|
"L1", the first input pad of overlay is labelled "L2", and the second
|
|
output pad of split is linked to the second input pad of overlay,
|
|
which are both unlabelled.
|
|
</p>
|
|
<p>In a complete filterchain all the unlabelled filter input and output
|
|
pads must be connected. A filtergraph is considered valid if all the
|
|
filter input and output pads of all the filterchains are connected.
|
|
</p>
|
|
<p>Follows a BNF description for the filtergraph syntax:
|
|
</p><table><tr><td> </td><td><pre class="example"><var>NAME</var> ::= sequence of alphanumeric characters and '_'
|
|
<var>LINKLABEL</var> ::= "[" <var>NAME</var> "]"
|
|
<var>LINKLABELS</var> ::= <var>LINKLABEL</var> [<var>LINKLABELS</var>]
|
|
<var>FILTER_ARGUMENTS</var> ::= sequence of chars (eventually quoted)
|
|
<var>FILTER</var> ::= [<var>LINKNAMES</var>] <var>NAME</var> ["=" <var>ARGUMENTS</var>] [<var>LINKNAMES</var>]
|
|
<var>FILTERCHAIN</var> ::= <var>FILTER</var> [,<var>FILTERCHAIN</var>]
|
|
<var>FILTERGRAPH</var> ::= <var>FILTERCHAIN</var> [;<var>FILTERGRAPH</var>]
|
|
</pre></td></tr></table>
|
|
|
|
|
|
<a name="Audio-Filters"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Audio-Filters">21. Audio Filters</a></h1>
|
|
|
|
<p>When you configure your FFmpeg build, you can disable any of the
|
|
existing filters using <code>--disable-filters</code>.
|
|
The configure output will show the audio filters included in your
|
|
build.
|
|
</p>
|
|
<p>Below is a description of the currently available audio filters.
|
|
</p>
|
|
<a name="aconvert"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-aconvert">21.1 aconvert</a></h2>
|
|
|
|
<p>Convert the input audio format to the specified formats.
|
|
</p>
|
|
<p>The filter accepts a string of the form:
|
|
"<var>sample_format</var>:<var>channel_layout</var>:<var>packing_format</var>".
|
|
</p>
|
|
<p><var>sample_format</var> specifies the sample format, and can be a string or
|
|
the corresponding numeric value defined in ‘<tt>libavutil/samplefmt.h</tt>’.
|
|
</p>
|
|
<p><var>channel_layout</var> specifies the channel layout, and can be a string
|
|
or the corresponding number value defined in ‘<tt>libavutil/audioconvert.h</tt>’.
|
|
</p>
|
|
<p><var>packing_format</var> specifies the type of packing in output, can be one
|
|
of "planar" or "packed", or the corresponding numeric values "0" or "1".
|
|
</p>
|
|
<p>The special parameter "auto", signifies that the filter will
|
|
automatically select the output format depending on the output filter.
|
|
</p>
|
|
<p>Some examples follow.
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
Convert input to unsigned 8-bit, stereo, packed:
|
|
<table><tr><td> </td><td><pre class="example">aconvert=u8:stereo:packed
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Convert input to unsigned 8-bit, automatically select out channel layout
|
|
and packing format:
|
|
<table><tr><td> </td><td><pre class="example">aconvert=u8:auto:auto
|
|
</pre></td></tr></table>
|
|
</li></ul>
|
|
|
|
<a name="aformat"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-aformat">21.2 aformat</a></h2>
|
|
|
|
<p>Convert the input audio to one of the specified formats. The framework will
|
|
negotiate the most appropriate format to minimize conversions.
|
|
</p>
|
|
<p>The filter accepts three lists of formats, separated by ":", in the form:
|
|
"<var>sample_formats</var>:<var>channel_layouts</var>:<var>packing_formats</var>".
|
|
</p>
|
|
<p>Elements in each list are separated by "," which has to be escaped in the
|
|
filtergraph specification.
|
|
</p>
|
|
<p>The special parameter "all", in place of a list of elements, signifies all
|
|
supported formats.
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example">aformat=u8\\,s16:mono:packed
|
|
|
|
aformat=s16:mono\\,stereo:all
|
|
</pre></td></tr></table>
|
|
|
|
<a name="amerge"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-amerge">21.3 amerge</a></h2>
|
|
|
|
<p>Merge two audio streams into a single multi-channel stream.
|
|
</p>
|
|
<p>This filter does not need any argument.
|
|
</p>
|
|
<p>If the channel layouts of the inputs are disjoint, and therefore compatible,
|
|
the channel layout of the output will be set accordingly and the channels
|
|
will be reordered as necessary. If the channel layouts of the inputs are not
|
|
disjoint, the output will have all the channels of the first input then all
|
|
the channels of the second input, in that order, and the channel layout of
|
|
the output will be the default value corresponding to the total number of
|
|
channels.
|
|
</p>
|
|
<p>For example, if the first input is in 2.1 (FL+FR+LF) and the second input
|
|
is FC+BL+BR, then the output will be in 5.1, with the channels in the
|
|
following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
|
|
first input, b1 is the first channel of the second input).
|
|
</p>
|
|
<p>On the other hand, if both input are in stereo, the output channels will be
|
|
in the default order: a1, a2, b1, b2, and the channel layout will be
|
|
arbitrarily set to 4.0, which may or may not be the expected value.
|
|
</p>
|
|
<p>Both inputs must have the same sample rate, format and packing.
|
|
</p>
|
|
<p>If inputs do not have the same duration, the output will stop with the
|
|
shortest.
|
|
</p>
|
|
<p>Example: merge two mono files into a stereo stream:
|
|
</p><table><tr><td> </td><td><pre class="example">amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
|
|
</pre></td></tr></table>
|
|
|
|
<a name="anull"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-anull">21.4 anull</a></h2>
|
|
|
|
<p>Pass the audio source unchanged to the output.
|
|
</p>
|
|
<a name="aresample"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-aresample">21.5 aresample</a></h2>
|
|
|
|
<p>Resample the input audio to the specified sample rate.
|
|
</p>
|
|
<p>The filter accepts exactly one parameter, the output sample rate. If not
|
|
specified then the filter will automatically convert between its input
|
|
and output sample rates.
|
|
</p>
|
|
<p>For example, to resample the input audio to 44100Hz:
|
|
</p><table><tr><td> </td><td><pre class="example">aresample=44100
|
|
</pre></td></tr></table>
|
|
|
|
<a name="ashowinfo"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-ashowinfo">21.6 ashowinfo</a></h2>
|
|
|
|
<p>Show a line containing various information for each input audio frame.
|
|
The input audio is not modified.
|
|
</p>
|
|
<p>The shown line contains a sequence of key/value pairs of the form
|
|
<var>key</var>:<var>value</var>.
|
|
</p>
|
|
<p>A description of each shown parameter follows:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>n</samp>’</dt>
|
|
<dd><p>sequential number of the input frame, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pts</samp>’</dt>
|
|
<dd><p>presentation TimeStamp of the input frame, expressed as a number of
|
|
time base units. The time base unit depends on the filter input pad, and
|
|
is usually 1/<var>sample_rate</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pts_time</samp>’</dt>
|
|
<dd><p>presentation TimeStamp of the input frame, expressed as a number of
|
|
seconds
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pos</samp>’</dt>
|
|
<dd><p>position of the frame in the input stream, -1 if this information in
|
|
unavailable and/or meaningless (for example in case of synthetic audio)
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>fmt</samp>’</dt>
|
|
<dd><p>sample format name
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>chlayout</samp>’</dt>
|
|
<dd><p>channel layout description
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>nb_samples</samp>’</dt>
|
|
<dd><p>number of samples (per each channel) contained in the filtered frame
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rate</samp>’</dt>
|
|
<dd><p>sample rate for the audio frame
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>planar</samp>’</dt>
|
|
<dd><p>if the packing format is planar, 0 if packed
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>checksum</samp>’</dt>
|
|
<dd><p>Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>plane_checksum</samp>’</dt>
|
|
<dd><p>Adler-32 checksum (printed in hexadecimal) for each input frame plane,
|
|
expressed in the form "[<var>c0</var> <var>c1</var> <var>c2</var> <var>c3</var> <var>c4</var> <var>c5</var>
|
|
<var>c6</var> <var>c7</var>]"
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="asplit"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-asplit">21.7 asplit</a></h2>
|
|
|
|
<p>Pass on the input audio to two outputs. Both outputs are identical to
|
|
the input audio.
|
|
</p>
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">[in] asplit[out0], showaudio[out1]
|
|
</pre></td></tr></table>
|
|
|
|
<p>will create two separate outputs from the same input, one cropped and
|
|
one padded.
|
|
</p>
|
|
<a name="astreamsync"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-astreamsync">21.8 astreamsync</a></h2>
|
|
|
|
<p>Forward two audio streams and control the order the buffers are forwarded.
|
|
</p>
|
|
<p>The argument to the filter is an expression deciding which stream should be
|
|
forwarded next: if the result is negative, the first stream is forwarded; if
|
|
the result is positive or zero, the second stream is forwarded. It can use
|
|
the following variables:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> <var>b1 b2</var></dt>
|
|
<dd><p>number of buffers forwarded so far on each stream
|
|
</p></dd>
|
|
<dt> <var>s1 s2</var></dt>
|
|
<dd><p>number of samples forwarded so far on each stream
|
|
</p></dd>
|
|
<dt> <var>t1 t2</var></dt>
|
|
<dd><p>current timestamp of each stream
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The default value is <code>t1-t2</code>, which means to always forward the stream
|
|
that has a smaller timestamp.
|
|
</p>
|
|
<p>Example: stress-test <code>amerge</code> by randomly sending buffers on the wrong
|
|
input, while avoiding too much of a desynchronization:
|
|
</p><table><tr><td> </td><td><pre class="example">amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
|
|
[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
|
|
[a2] [b2] amerge
|
|
</pre></td></tr></table>
|
|
|
|
<a name="earwax"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-earwax">21.9 earwax</a></h2>
|
|
|
|
<p>Make audio easier to listen to on headphones.
|
|
</p>
|
|
<p>This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
|
|
so that when listened to on headphones the stereo image is moved from
|
|
inside your head (standard for headphones) to outside and in front of
|
|
the listener (standard for speakers).
|
|
</p>
|
|
<p>Ported from SoX.
|
|
</p>
|
|
<a name="pan"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-pan">21.10 pan</a></h2>
|
|
|
|
<p>Mix channels with specific gain levels. The filter accepts the output
|
|
channel layout followed by a set of channels definitions.
|
|
</p>
|
|
<p>This filter is also designed to remap efficiently the channels of an audio
|
|
stream.
|
|
</p>
|
|
<p>The filter accepts parameters of the form:
|
|
"<var>l</var>:<var>outdef</var>:<var>outdef</var>:..."
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>l</samp>’</dt>
|
|
<dd><p>output channel layout or number of channels
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>outdef</samp>’</dt>
|
|
<dd><p>output channel specification, of the form:
|
|
"<var>out_name</var>=[<var>gain</var>*]<var>in_name</var>[+[<var>gain</var>*]<var>in_name</var>...]"
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>out_name</samp>’</dt>
|
|
<dd><p>output channel to define, either a channel name (FL, FR, etc.) or a channel
|
|
number (c0, c1, etc.)
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>gain</samp>’</dt>
|
|
<dd><p>multiplicative coefficient for the channel, 1 leaving the volume unchanged
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>in_name</samp>’</dt>
|
|
<dd><p>input channel to use, see out_name for details; it is not possible to mix
|
|
named and numbered input channels
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
|
|
that specification will be renormalized so that the total is 1, thus
|
|
avoiding clipping noise.
|
|
</p>
|
|
<a name="Mixing-examples"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Mixing-examples">21.10.1 Mixing examples</a></h3>
|
|
|
|
<p>For example, if you want to down-mix from stereo to mono, but with a bigger
|
|
factor for the left channel:
|
|
</p><table><tr><td> </td><td><pre class="example">pan=1:c0=0.9*c0+0.1*c1
|
|
</pre></td></tr></table>
|
|
|
|
<p>A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
|
|
7-channels surround:
|
|
</p><table><tr><td> </td><td><pre class="example">pan=stereo: FL < FL + 0.5*FC + 0.6*BL + 0.6*SL : FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that <code>ffmpeg</code> integrates a default down-mix (and up-mix) system
|
|
that should be preferred (see "-ac" option) unless you have very specific
|
|
needs.
|
|
</p>
|
|
<a name="Remapping-examples"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Remapping-examples">21.10.2 Remapping examples</a></h3>
|
|
|
|
<p>The channel remapping will be effective if, and only if:
|
|
</p>
|
|
<ul>
|
|
<li> gain coefficients are zeroes or ones,
|
|
</li><li> only one input per channel output,
|
|
</li><li> the number of output channels is supported by libswresample (16 at the
|
|
moment)
|
|
</li></ul>
|
|
|
|
<p>If all these conditions are satisfied, the filter will notify the user ("Pure
|
|
channel mapping detected"), and use an optimized and lossless method to do the
|
|
remapping.
|
|
</p>
|
|
<p>For example, if you have a 5.1 source and want a stereo audio stream by
|
|
dropping the extra channels:
|
|
</p><table><tr><td> </td><td><pre class="example">pan="stereo: c0=FL : c1=FR"
|
|
</pre></td></tr></table>
|
|
|
|
<p>Given the same source, you can also switch front left and front right channels
|
|
and keep the input channel layout:
|
|
</p><table><tr><td> </td><td><pre class="example">pan="5.1: c0=c1 : c1=c0 : c2=c2 : c3=c3 : c4=c4 : c5=c5"
|
|
</pre></td></tr></table>
|
|
|
|
<p>If the input is a stereo audio stream, you can mute the front left channel (and
|
|
still keep the stereo channel layout) with:
|
|
</p><table><tr><td> </td><td><pre class="example">pan="stereo:c1=c1"
|
|
</pre></td></tr></table>
|
|
|
|
<p>Still with a stereo audio stream input, you can copy the right channel in both
|
|
front left and right:
|
|
</p><table><tr><td> </td><td><pre class="example">pan="stereo: c0=FR : c1=FR"
|
|
</pre></td></tr></table>
|
|
|
|
<a name="silencedetect"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-silencedetect">21.11 silencedetect</a></h2>
|
|
|
|
<p>Detect silence in an audio stream.
|
|
</p>
|
|
<p>This filter logs a message when it detects that the input audio volume is less
|
|
or equal to a noise tolerance value for a duration greater or equal to the
|
|
minimum detected noise duration.
|
|
</p>
|
|
<p>The printed times and duration are expressed in seconds.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>duration, d</samp>’</dt>
|
|
<dd><p>Set silence duration until notification (default is 2 seconds).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>noise, n</samp>’</dt>
|
|
<dd><p>Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
|
|
specified value) or amplitude ratio. Default is -60dB, or 0.001.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Detect 5 seconds of silence with -50dB noise tolerance:
|
|
</p><table><tr><td> </td><td><pre class="example">silencedetect=n=-50dB:d=5
|
|
</pre></td></tr></table>
|
|
|
|
<p>Complete example with <code>ffmpeg</code> to detect silence with 0.0001 noise
|
|
tolerance in ‘<tt>silence.mp3</tt>’:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -f lavfi -i amovie=silence.mp3,silencedetect=noise=0.0001 -f null -
|
|
</pre></td></tr></table>
|
|
|
|
<a name="volume"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-volume">21.12 volume</a></h2>
|
|
|
|
<p>Adjust the input audio volume.
|
|
</p>
|
|
<p>The filter accepts exactly one parameter <var>vol</var>, which expresses
|
|
how the audio volume will be increased or decreased.
|
|
</p>
|
|
<p>Output values are clipped to the maximum value.
|
|
</p>
|
|
<p>If <var>vol</var> is expressed as a decimal number, the output audio
|
|
volume is given by the relation:
|
|
</p><table><tr><td> </td><td><pre class="example"><var>output_volume</var> = <var>vol</var> * <var>input_volume</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>If <var>vol</var> is expressed as a decimal number followed by the string
|
|
"dB", the value represents the requested change in decibels of the
|
|
input audio power, and the output audio volume is given by the
|
|
relation:
|
|
</p><table><tr><td> </td><td><pre class="example"><var>output_volume</var> = 10^(<var>vol</var>/20) * <var>input_volume</var>
|
|
</pre></td></tr></table>
|
|
|
|
<p>Otherwise <var>vol</var> is considered an expression and its evaluated
|
|
value is used for computing the output audio volume according to the
|
|
first relation.
|
|
</p>
|
|
<p>Default value for <var>vol</var> is 1.0.
|
|
</p>
|
|
<a name="Examples-1"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-1">21.12.1 Examples</a></h3>
|
|
|
|
<ul>
|
|
<li>
|
|
Half the input audio volume:
|
|
<table><tr><td> </td><td><pre class="example">volume=0.5
|
|
</pre></td></tr></table>
|
|
|
|
<p>The above example is equivalent to:
|
|
</p><table><tr><td> </td><td><pre class="example">volume=1/2
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Decrease input audio power by 12 decibels:
|
|
<table><tr><td> </td><td><pre class="example">volume=-12dB
|
|
</pre></td></tr></table>
|
|
</li></ul>
|
|
|
|
|
|
<a name="Audio-Sources"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Audio-Sources">22. Audio Sources</a></h1>
|
|
|
|
<p>Below is a description of the currently available audio sources.
|
|
</p>
|
|
<a name="abuffer"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-abuffer">22.1 abuffer</a></h2>
|
|
|
|
<p>Buffer audio frames, and make them available to the filter chain.
|
|
</p>
|
|
<p>This source is mainly intended for a programmatic use, in particular
|
|
through the interface defined in ‘<tt>libavfilter/asrc_abuffer.h</tt>’.
|
|
</p>
|
|
<p>It accepts the following mandatory parameters:
|
|
<var>sample_rate</var>:<var>sample_fmt</var>:<var>channel_layout</var>:<var>packing</var>
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>sample_rate</samp>’</dt>
|
|
<dd><p>The sample rate of the incoming audio buffers.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sample_fmt</samp>’</dt>
|
|
<dd><p>The sample format of the incoming audio buffers.
|
|
Either a sample format name or its corresponging integer representation from
|
|
the enum AVSampleFormat in ‘<tt>libavutil/samplefmt.h</tt>’
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>channel_layout</samp>’</dt>
|
|
<dd><p>The channel layout of the incoming audio buffers.
|
|
Either a channel layout name from channel_layout_map in
|
|
‘<tt>libavutil/audioconvert.c</tt>’ or its corresponding integer representation
|
|
from the AV_CH_LAYOUT_* macros in ‘<tt>libavutil/audioconvert.h</tt>’
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>packing</samp>’</dt>
|
|
<dd><p>Either "packed" or "planar", or their integer representation: 0 or 1
|
|
respectively.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">abuffer=44100:s16:stereo:planar
|
|
</pre></td></tr></table>
|
|
|
|
<p>will instruct the source to accept planar 16bit signed stereo at 44100Hz.
|
|
Since the sample format with name "s16" corresponds to the number
|
|
1 and the "stereo" channel layout corresponds to the value 3, this is
|
|
equivalent to:
|
|
</p><table><tr><td> </td><td><pre class="example">abuffer=44100:1:3:1
|
|
</pre></td></tr></table>
|
|
|
|
<a name="aevalsrc"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-aevalsrc">22.2 aevalsrc</a></h2>
|
|
|
|
<p>Generate an audio signal specified by an expression.
|
|
</p>
|
|
<p>This source accepts in input one or more expressions (one for each
|
|
channel), which are evaluated and used to generate a corresponding
|
|
audio signal.
|
|
</p>
|
|
<p>It accepts the syntax: <var>exprs</var>[::<var>options</var>].
|
|
<var>exprs</var> is a list of expressions separated by ":", one for each
|
|
separate channel. The output channel layout depends on the number of
|
|
provided expressions, up to 8 channels are supported.
|
|
</p>
|
|
<p><var>options</var> is an optional sequence of <var>key</var>=<var>value</var> pairs,
|
|
separated by ":".
|
|
</p>
|
|
<p>The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>duration, d</samp>’</dt>
|
|
<dd><p>Set the minimum duration of the sourced audio. See the function
|
|
<code>av_parse_time()</code> for the accepted format.
|
|
Note that the resulting duration may be greater than the specified
|
|
duration, as the generated audio is always cut at the end of a
|
|
complete frame.
|
|
</p>
|
|
<p>If not specified, or the expressed duration is negative, the audio is
|
|
supposed to be generated forever.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>nb_samples, n</samp>’</dt>
|
|
<dd><p>Set the number of samples per channel per each output frame,
|
|
default to 1024.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sample_rate, s</samp>’</dt>
|
|
<dd><p>Specify the sample rate, default to 44100.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Each expression in <var>exprs</var> can contain the following constants:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>n</samp>’</dt>
|
|
<dd><p>number of the evaluated sample, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>t</samp>’</dt>
|
|
<dd><p>time of the evaluated sample expressed in seconds, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>s</samp>’</dt>
|
|
<dd><p>sample rate
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Examples-4"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-4">22.2.1 Examples</a></h3>
|
|
|
|
<ul>
|
|
<li>
|
|
Generate silence:
|
|
<table><tr><td> </td><td><pre class="example">aevalsrc=0
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
|
|
Generate a sin signal with frequency of 440 Hz, set sample rate to
|
|
8000 Hz:
|
|
<table><tr><td> </td><td><pre class="example">aevalsrc="sin(440*2*PI*t)::s=8000"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Generate white noise:
|
|
<table><tr><td> </td><td><pre class="example">aevalsrc="-2+random(0)"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Generate an amplitude modulated signal:
|
|
<table><tr><td> </td><td><pre class="example">aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Generate 2.5 Hz binaural beats on a 360 Hz carrier:
|
|
<table><tr><td> </td><td><pre class="example">aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) : 0.1*sin(2*PI*(360+2.5/2)*t)"
|
|
</pre></td></tr></table>
|
|
|
|
</li></ul>
|
|
|
|
<a name="amovie"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-amovie">22.3 amovie</a></h2>
|
|
|
|
<p>Read an audio stream from a movie container.
|
|
</p>
|
|
<p>It accepts the syntax: <var>movie_name</var>[:<var>options</var>] where
|
|
<var>movie_name</var> is the name of the resource to read (not necessarily
|
|
a file but also a device or a stream accessed through some protocol),
|
|
and <var>options</var> is an optional sequence of <var>key</var>=<var>value</var>
|
|
pairs, separated by ":".
|
|
</p>
|
|
<p>The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>format_name, f</samp>’</dt>
|
|
<dd><p>Specify the format assumed for the movie to read, and can be either
|
|
the name of a container or an input device. If not specified the
|
|
format is guessed from <var>movie_name</var> or by probing.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>seek_point, sp</samp>’</dt>
|
|
<dd><p>Specify the seek point in seconds, the frames will be output
|
|
starting from this seek point, the parameter is evaluated with
|
|
<code>av_strtod</code> so the numerical value may be suffixed by an IS
|
|
postfix. Default value is "0".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>stream_index, si</samp>’</dt>
|
|
<dd><p>Specify the index of the audio stream to read. If the value is -1,
|
|
the best suited audio stream will be automatically selected. Default
|
|
value is "-1".
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="anullsrc"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-anullsrc">22.4 anullsrc</a></h2>
|
|
|
|
<p>Null audio source, return unprocessed audio frames. It is mainly useful
|
|
as a template and to be employed in analysis / debugging tools, or as
|
|
the source for filters which ignore the input data (for example the sox
|
|
synth filter).
|
|
</p>
|
|
<p>It accepts an optional sequence of <var>key</var>=<var>value</var> pairs,
|
|
separated by ":".
|
|
</p>
|
|
<p>The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>sample_rate, s</samp>’</dt>
|
|
<dd><p>Specify the sample rate, and defaults to 44100.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>channel_layout, cl</samp>’</dt>
|
|
<dd>
|
|
<p>Specify the channel layout, and can be either an integer or a string
|
|
representing a channel layout. The default value of <var>channel_layout</var>
|
|
is "stereo".
|
|
</p>
|
|
<p>Check the channel_layout_map definition in
|
|
‘<tt>libavcodec/audioconvert.c</tt>’ for the mapping between strings and
|
|
channel layout values.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>nb_samples, n</samp>’</dt>
|
|
<dd><p>Set the number of samples per requested frames.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>Follow some examples:
|
|
</p><table><tr><td> </td><td><pre class="example"># set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
|
|
anullsrc=r=48000:cl=4
|
|
|
|
# same as
|
|
anullsrc=r=48000:cl=mono
|
|
</pre></td></tr></table>
|
|
|
|
|
|
<a name="Audio-Sinks"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Audio-Sinks">23. Audio Sinks</a></h1>
|
|
|
|
<p>Below is a description of the currently available audio sinks.
|
|
</p>
|
|
<a name="abuffersink"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-abuffersink">23.1 abuffersink</a></h2>
|
|
|
|
<p>Buffer audio frames, and make them available to the end of filter chain.
|
|
</p>
|
|
<p>This sink is mainly intended for programmatic use, in particular
|
|
through the interface defined in ‘<tt>libavfilter/buffersink.h</tt>’.
|
|
</p>
|
|
<p>It requires a pointer to an AVABufferSinkContext structure, which
|
|
defines the incoming buffers’ formats, to be passed as the opaque
|
|
parameter to <code>avfilter_init_filter</code> for initialization.
|
|
</p>
|
|
<a name="anullsink"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-anullsink">23.2 anullsink</a></h2>
|
|
|
|
<p>Null audio sink, do absolutely nothing with the input audio. It is
|
|
mainly useful as a template and to be employed in analysis / debugging
|
|
tools.
|
|
</p>
|
|
|
|
<a name="Video-Filters"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Video-Filters">24. Video Filters</a></h1>
|
|
|
|
<p>When you configure your FFmpeg build, you can disable any of the
|
|
existing filters using <code>--disable-filters</code>.
|
|
The configure output will show the video filters included in your
|
|
build.
|
|
</p>
|
|
<p>Below is a description of the currently available video filters.
|
|
</p>
|
|
<a name="ass"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-ass">24.1 ass</a></h2>
|
|
|
|
<p>Draw ASS (Advanced Substation Alpha) subtitles on top of input video
|
|
using the libass library.
|
|
</p>
|
|
<p>To enable compilation of this filter you need to configure FFmpeg with
|
|
<code>--enable-libass</code>.
|
|
</p>
|
|
<p>This filter accepts in input the name of the ass file to render.
|
|
</p>
|
|
<p>For example, to render the file ‘<tt>sub.ass</tt>’ on top of the input
|
|
video, use the command:
|
|
</p><table><tr><td> </td><td><pre class="example">ass=sub.ass
|
|
</pre></td></tr></table>
|
|
|
|
<a name="blackframe"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-blackframe">24.2 blackframe</a></h2>
|
|
|
|
<p>Detect frames that are (almost) completely black. Can be useful to
|
|
detect chapter transitions or commercials. Output lines consist of
|
|
the frame number of the detected frame, the percentage of blackness,
|
|
the position in the file if known or -1 and the timestamp in seconds.
|
|
</p>
|
|
<p>In order to display the output lines, you need to set the loglevel at
|
|
least to the AV_LOG_INFO value.
|
|
</p>
|
|
<p>The filter accepts the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example">blackframe[=<var>amount</var>:[<var>threshold</var>]]
|
|
</pre></td></tr></table>
|
|
|
|
<p><var>amount</var> is the percentage of the pixels that have to be below the
|
|
threshold, and defaults to 98.
|
|
</p>
|
|
<p><var>threshold</var> is the threshold below which a pixel value is
|
|
considered black, and defaults to 32.
|
|
</p>
|
|
<a name="boxblur"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-boxblur">24.3 boxblur</a></h2>
|
|
|
|
<p>Apply boxblur algorithm to the input video.
|
|
</p>
|
|
<p>This filter accepts the parameters:
|
|
<var>luma_radius</var>:<var>luma_power</var>:<var>chroma_radius</var>:<var>chroma_power</var>:<var>alpha_radius</var>:<var>alpha_power</var>
|
|
</p>
|
|
<p>Chroma and alpha parameters are optional, if not specified they default
|
|
to the corresponding values set for <var>luma_radius</var> and
|
|
<var>luma_power</var>.
|
|
</p>
|
|
<p><var>luma_radius</var>, <var>chroma_radius</var>, and <var>alpha_radius</var> represent
|
|
the radius in pixels of the box used for blurring the corresponding
|
|
input plane. They are expressions, and can contain the following
|
|
constants:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>w, h</samp>’</dt>
|
|
<dd><p>the input width and height in pixels
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>cw, ch</samp>’</dt>
|
|
<dd><p>the input chroma image width and height in pixels
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>hsub, vsub</samp>’</dt>
|
|
<dd><p>horizontal and vertical chroma subsample values. For example for the
|
|
pixel format "yuv422p" <var>hsub</var> is 2 and <var>vsub</var> is 1.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The radius must be a non-negative number, and must not be greater than
|
|
the value of the expression <code>min(w,h)/2</code> for the luma and alpha planes,
|
|
and of <code>min(cw,ch)/2</code> for the chroma planes.
|
|
</p>
|
|
<p><var>luma_power</var>, <var>chroma_power</var>, and <var>alpha_power</var> represent
|
|
how many times the boxblur filter is applied to the corresponding
|
|
plane.
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
Apply a boxblur filter with luma, chroma, and alpha radius
|
|
set to 2:
|
|
<table><tr><td> </td><td><pre class="example">boxblur=2:1
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Set luma radius to 2, alpha and chroma radius to 0
|
|
<table><tr><td> </td><td><pre class="example">boxblur=2:1:0:0:0:0
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Set luma and chroma radius to a fraction of the video dimension
|
|
<table><tr><td> </td><td><pre class="example">boxblur=min(h\,w)/10:1:min(cw\,ch)/10:1
|
|
</pre></td></tr></table>
|
|
|
|
</li></ul>
|
|
|
|
<a name="copy"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-copy">24.4 copy</a></h2>
|
|
|
|
<p>Copy the input source unchanged to the output. Mainly useful for
|
|
testing purposes.
|
|
</p>
|
|
<a name="crop"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-crop">24.5 crop</a></h2>
|
|
|
|
<p>Crop the input video to <var>out_w</var>:<var>out_h</var>:<var>x</var>:<var>y</var>.
|
|
</p>
|
|
<p>The parameters are expressions containing the following constants:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>x, y</samp>’</dt>
|
|
<dd><p>the computed values for <var>x</var> and <var>y</var>. They are evaluated for
|
|
each new frame.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>in_w, in_h</samp>’</dt>
|
|
<dd><p>the input width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>iw, ih</samp>’</dt>
|
|
<dd><p>same as <var>in_w</var> and <var>in_h</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>out_w, out_h</samp>’</dt>
|
|
<dd><p>the output (cropped) width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ow, oh</samp>’</dt>
|
|
<dd><p>same as <var>out_w</var> and <var>out_h</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>a</samp>’</dt>
|
|
<dd><p>same as <var>iw</var> / <var>ih</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sar</samp>’</dt>
|
|
<dd><p>input sample aspect ratio
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>dar</samp>’</dt>
|
|
<dd><p>input display aspect ratio, it is the same as (<var>iw</var> / <var>ih</var>) * <var>sar</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>hsub, vsub</samp>’</dt>
|
|
<dd><p>horizontal and vertical chroma subsample values. For example for the
|
|
pixel format "yuv422p" <var>hsub</var> is 2 and <var>vsub</var> is 1.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>n</samp>’</dt>
|
|
<dd><p>the number of input frame, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pos</samp>’</dt>
|
|
<dd><p>the position in the file of the input frame, NAN if unknown
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>t</samp>’</dt>
|
|
<dd><p>timestamp expressed in seconds, NAN if the input timestamp is unknown
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>The <var>out_w</var> and <var>out_h</var> parameters specify the expressions for
|
|
the width and height of the output (cropped) video. They are
|
|
evaluated just at the configuration of the filter.
|
|
</p>
|
|
<p>The default value of <var>out_w</var> is "in_w", and the default value of
|
|
<var>out_h</var> is "in_h".
|
|
</p>
|
|
<p>The expression for <var>out_w</var> may depend on the value of <var>out_h</var>,
|
|
and the expression for <var>out_h</var> may depend on <var>out_w</var>, but they
|
|
cannot depend on <var>x</var> and <var>y</var>, as <var>x</var> and <var>y</var> are
|
|
evaluated after <var>out_w</var> and <var>out_h</var>.
|
|
</p>
|
|
<p>The <var>x</var> and <var>y</var> parameters specify the expressions for the
|
|
position of the top-left corner of the output (non-cropped) area. They
|
|
are evaluated for each frame. If the evaluated value is not valid, it
|
|
is approximated to the nearest valid value.
|
|
</p>
|
|
<p>The default value of <var>x</var> is "(in_w-out_w)/2", and the default
|
|
value for <var>y</var> is "(in_h-out_h)/2", which set the cropped area at
|
|
the center of the input image.
|
|
</p>
|
|
<p>The expression for <var>x</var> may depend on <var>y</var>, and the expression
|
|
for <var>y</var> may depend on <var>x</var>.
|
|
</p>
|
|
<p>Follow some examples:
|
|
</p><table><tr><td> </td><td><pre class="example"># crop the central input area with size 100x100
|
|
crop=100:100
|
|
|
|
# crop the central input area with size 2/3 of the input video
|
|
"crop=2/3*in_w:2/3*in_h"
|
|
|
|
# crop the input video central square
|
|
crop=in_h
|
|
|
|
# delimit the rectangle with the top-left corner placed at position
|
|
# 100:100 and the right-bottom corner corresponding to the right-bottom
|
|
# corner of the input image.
|
|
crop=in_w-100:in_h-100:100:100
|
|
|
|
# crop 10 pixels from the left and right borders, and 20 pixels from
|
|
# the top and bottom borders
|
|
"crop=in_w-2*10:in_h-2*20"
|
|
|
|
# keep only the bottom right quarter of the input image
|
|
"crop=in_w/2:in_h/2:in_w/2:in_h/2"
|
|
|
|
# crop height for getting Greek harmony
|
|
"crop=in_w:1/PHI*in_w"
|
|
|
|
# trembling effect
|
|
"crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)"
|
|
|
|
# erratic camera effect depending on timestamp
|
|
"crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"
|
|
|
|
# set x depending on the value of y
|
|
"crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
|
|
</pre></td></tr></table>
|
|
|
|
<a name="cropdetect"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-cropdetect">24.6 cropdetect</a></h2>
|
|
|
|
<p>Auto-detect crop size.
|
|
</p>
|
|
<p>Calculate necessary cropping parameters and prints the recommended
|
|
parameters through the logging system. The detected dimensions
|
|
correspond to the non-black area of the input video.
|
|
</p>
|
|
<p>It accepts the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example">cropdetect[=<var>limit</var>[:<var>round</var>[:<var>reset</var>]]]
|
|
</pre></td></tr></table>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>limit</samp>’</dt>
|
|
<dd><p>Threshold, which can be optionally specified from nothing (0) to
|
|
everything (255), defaults to 24.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>round</samp>’</dt>
|
|
<dd><p>Value which the width/height should be divisible by, defaults to
|
|
16. The offset is automatically adjusted to center the video. Use 2 to
|
|
get only even dimensions (needed for 4:2:2 video). 16 is best when
|
|
encoding to most video codecs.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>reset</samp>’</dt>
|
|
<dd><p>Counter that determines after how many frames cropdetect will reset
|
|
the previously detected largest video area and start over to detect
|
|
the current optimal crop area. Defaults to 0.
|
|
</p>
|
|
<p>This can be useful when channel logos distort the video area. 0
|
|
indicates never reset and return the largest area encountered during
|
|
playback.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="delogo"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-delogo">24.7 delogo</a></h2>
|
|
|
|
<p>Suppress a TV station logo by a simple interpolation of the surrounding
|
|
pixels. Just set a rectangle covering the logo and watch it disappear
|
|
(and sometimes something even uglier appear - your mileage may vary).
|
|
</p>
|
|
<p>The filter accepts parameters as a string of the form
|
|
"<var>x</var>:<var>y</var>:<var>w</var>:<var>h</var>:<var>band</var>", or as a list of
|
|
<var>key</var>=<var>value</var> pairs, separated by ":".
|
|
</p>
|
|
<p>The description of the accepted parameters follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>x, y</samp>’</dt>
|
|
<dd><p>Specify the top left corner coordinates of the logo. They must be
|
|
specified.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>w, h</samp>’</dt>
|
|
<dd><p>Specify the width and height of the logo to clear. They must be
|
|
specified.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>band, t</samp>’</dt>
|
|
<dd><p>Specify the thickness of the fuzzy edge of the rectangle (added to
|
|
<var>w</var> and <var>h</var>). The default value is 4.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>show</samp>’</dt>
|
|
<dd><p>When set to 1, a green rectangle is drawn on the screen to simplify
|
|
finding the right <var>x</var>, <var>y</var>, <var>w</var>, <var>h</var> parameters, and
|
|
<var>band</var> is set to 4. The default value is 0.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>Some examples follow.
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
Set a rectangle covering the area with top left corner coordinates 0,0
|
|
and size 100x77, setting a band of size 10:
|
|
<table><tr><td> </td><td><pre class="example">delogo=0:0:100:77:10
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
As the previous example, but use named options:
|
|
<table><tr><td> </td><td><pre class="example">delogo=x=0:y=0:w=100:h=77:band=10
|
|
</pre></td></tr></table>
|
|
|
|
</li></ul>
|
|
|
|
<a name="deshake"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-deshake">24.8 deshake</a></h2>
|
|
|
|
<p>Attempt to fix small changes in horizontal and/or vertical shift. This
|
|
filter helps remove camera shake from hand-holding a camera, bumping a
|
|
tripod, moving on a vehicle, etc.
|
|
</p>
|
|
<p>The filter accepts parameters as a string of the form
|
|
"<var>x</var>:<var>y</var>:<var>w</var>:<var>h</var>:<var>rx</var>:<var>ry</var>:<var>edge</var>:<var>blocksize</var>:<var>contrast</var>:<var>search</var>:<var>filename</var>"
|
|
</p>
|
|
<p>A description of the accepted parameters follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>x, y, w, h</samp>’</dt>
|
|
<dd><p>Specify a rectangular area where to limit the search for motion
|
|
vectors.
|
|
If desired the search for motion vectors can be limited to a
|
|
rectangular area of the frame defined by its top left corner, width
|
|
and height. These parameters have the same meaning as the drawbox
|
|
filter which can be used to visualise the position of the bounding
|
|
box.
|
|
</p>
|
|
<p>This is useful when simultaneous movement of subjects within the frame
|
|
might be confused for camera motion by the motion vector search.
|
|
</p>
|
|
<p>If any or all of <var>x</var>, <var>y</var>, <var>w</var> and <var>h</var> are set to -1
|
|
then the full frame is used. This allows later options to be set
|
|
without specifying the bounding box for the motion vector search.
|
|
</p>
|
|
<p>Default - search the whole frame.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rx, ry</samp>’</dt>
|
|
<dd><p>Specify the maximum extent of movement in x and y directions in the
|
|
range 0-64 pixels. Default 16.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>edge</samp>’</dt>
|
|
<dd><p>Specify how to generate pixels to fill blanks at the edge of the
|
|
frame. An integer from 0 to 3 as follows:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>Fill zeroes at blank locations
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>Original image at blank locations
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>Extruded edge value at blank locations
|
|
</p></dd>
|
|
<dt> ‘<samp>3</samp>’</dt>
|
|
<dd><p>Mirrored edge at blank locations
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The default setting is mirror edge at blank locations.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>blocksize</samp>’</dt>
|
|
<dd><p>Specify the blocksize to use for motion search. Range 4-128 pixels,
|
|
default 8.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>contrast</samp>’</dt>
|
|
<dd><p>Specify the contrast threshold for blocks. Only blocks with more than
|
|
the specified contrast (difference between darkest and lightest
|
|
pixels) will be considered. Range 1-255, default 125.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>search</samp>’</dt>
|
|
<dd><p>Specify the search strategy 0 = exhaustive search, 1 = less exhaustive
|
|
search. Default - exhaustive search.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>filename</samp>’</dt>
|
|
<dd><p>If set then a detailed log of the motion search is written to the
|
|
specified file.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="drawbox"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-drawbox">24.9 drawbox</a></h2>
|
|
|
|
<p>Draw a colored box on the input image.
|
|
</p>
|
|
<p>It accepts the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example">drawbox=<var>x</var>:<var>y</var>:<var>width</var>:<var>height</var>:<var>color</var>
|
|
</pre></td></tr></table>
|
|
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>x, y</samp>’</dt>
|
|
<dd><p>Specify the top left corner coordinates of the box. Default to 0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>width, height</samp>’</dt>
|
|
<dd><p>Specify the width and height of the box, if 0 they are interpreted as
|
|
the input width and height. Default to 0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>color</samp>’</dt>
|
|
<dd><p>Specify the color of the box to write, it can be the name of a color
|
|
(case insensitive match) or a 0xRRGGBB[AA] sequence.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Follow some examples:
|
|
</p><table><tr><td> </td><td><pre class="example"># draw a black box around the edge of the input image
|
|
drawbox
|
|
|
|
# draw a box with color red and an opacity of 50%
|
|
drawbox=10:20:200:60:red@0.5"
|
|
</pre></td></tr></table>
|
|
|
|
<a name="drawtext"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-drawtext">24.10 drawtext</a></h2>
|
|
|
|
<p>Draw text string or text from specified file on top of video using the
|
|
libfreetype library.
|
|
</p>
|
|
<p>To enable compilation of this filter you need to configure FFmpeg with
|
|
<code>--enable-libfreetype</code>.
|
|
</p>
|
|
<p>The filter also recognizes strftime() sequences in the provided text
|
|
and expands them accordingly. Check the documentation of strftime().
|
|
</p>
|
|
<p>The filter accepts parameters as a list of <var>key</var>=<var>value</var> pairs,
|
|
separated by ":".
|
|
</p>
|
|
<p>The description of the accepted parameters follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>fontfile</samp>’</dt>
|
|
<dd><p>The font file to be used for drawing text. Path must be included.
|
|
This parameter is mandatory.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>text</samp>’</dt>
|
|
<dd><p>The text string to be drawn. The text must be a sequence of UTF-8
|
|
encoded characters.
|
|
This parameter is mandatory if no file is specified with the parameter
|
|
<var>textfile</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>textfile</samp>’</dt>
|
|
<dd><p>A text file containing text to be drawn. The text must be a sequence
|
|
of UTF-8 encoded characters.
|
|
</p>
|
|
<p>This parameter is mandatory if no text string is specified with the
|
|
parameter <var>text</var>.
|
|
</p>
|
|
<p>If both text and textfile are specified, an error is thrown.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>x, y</samp>’</dt>
|
|
<dd><p>The expressions which specify the offsets where text will be drawn
|
|
within the video frame. They are relative to the top/left border of the
|
|
output image.
|
|
</p>
|
|
<p>The default value of <var>x</var> and <var>y</var> is "0".
|
|
</p>
|
|
<p>See below for the list of accepted constants.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>fontsize</samp>’</dt>
|
|
<dd><p>The font size to be used for drawing text.
|
|
The default value of <var>fontsize</var> is 16.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>fontcolor</samp>’</dt>
|
|
<dd><p>The color to be used for drawing fonts.
|
|
Either a string (e.g. "red") or in 0xRRGGBB[AA] format
|
|
(e.g. "0xff000033"), possibly followed by an alpha specifier.
|
|
The default value of <var>fontcolor</var> is "black".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>boxcolor</samp>’</dt>
|
|
<dd><p>The color to be used for drawing box around text.
|
|
Either a string (e.g. "yellow") or in 0xRRGGBB[AA] format
|
|
(e.g. "0xff00ff"), possibly followed by an alpha specifier.
|
|
The default value of <var>boxcolor</var> is "white".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>box</samp>’</dt>
|
|
<dd><p>Used to draw a box around text using background color.
|
|
Value should be either 1 (enable) or 0 (disable).
|
|
The default value of <var>box</var> is 0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>shadowx, shadowy</samp>’</dt>
|
|
<dd><p>The x and y offsets for the text shadow position with respect to the
|
|
position of the text. They can be either positive or negative
|
|
values. Default value for both is "0".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>shadowcolor</samp>’</dt>
|
|
<dd><p>The color to be used for drawing a shadow behind the drawn text. It
|
|
can be a color name (e.g. "yellow") or a string in the 0xRRGGBB[AA]
|
|
form (e.g. "0xff00ff"), possibly followed by an alpha specifier.
|
|
The default value of <var>shadowcolor</var> is "black".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ft_load_flags</samp>’</dt>
|
|
<dd><p>Flags to be used for loading the fonts.
|
|
</p>
|
|
<p>The flags map the corresponding flags supported by libfreetype, and are
|
|
a combination of the following values:
|
|
</p><dl compact="compact">
|
|
<dt> <var>default</var></dt>
|
|
<dt> <var>no_scale</var></dt>
|
|
<dt> <var>no_hinting</var></dt>
|
|
<dt> <var>render</var></dt>
|
|
<dt> <var>no_bitmap</var></dt>
|
|
<dt> <var>vertical_layout</var></dt>
|
|
<dt> <var>force_autohint</var></dt>
|
|
<dt> <var>crop_bitmap</var></dt>
|
|
<dt> <var>pedantic</var></dt>
|
|
<dt> <var>ignore_global_advance_width</var></dt>
|
|
<dt> <var>no_recurse</var></dt>
|
|
<dt> <var>ignore_transform</var></dt>
|
|
<dt> <var>monochrome</var></dt>
|
|
<dt> <var>linear_design</var></dt>
|
|
<dt> <var>no_autohint</var></dt>
|
|
<dt> <var>end table</var></dt>
|
|
</dl>
|
|
|
|
<p>Default value is "render".
|
|
</p>
|
|
<p>For more information consult the documentation for the FT_LOAD_*
|
|
libfreetype flags.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>tabsize</samp>’</dt>
|
|
<dd><p>The size in number of spaces to use for rendering the tab.
|
|
Default value is 4.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The parameters for <var>x</var> and <var>y</var> are expressions containing the
|
|
following constants:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>W, H</samp>’</dt>
|
|
<dd><p>the input width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>tw, text_w</samp>’</dt>
|
|
<dd><p>the width of the rendered text
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>th, text_h</samp>’</dt>
|
|
<dd><p>the height of the rendered text
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>lh, line_h</samp>’</dt>
|
|
<dd><p>the height of each text line
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sar</samp>’</dt>
|
|
<dd><p>input sample aspect ratio
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>dar</samp>’</dt>
|
|
<dd><p>input display aspect ratio, it is the same as (<var>w</var> / <var>h</var>) * <var>sar</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>hsub, vsub</samp>’</dt>
|
|
<dd><p>horizontal and vertical chroma subsample values. For example for the
|
|
pixel format "yuv422p" <var>hsub</var> is 2 and <var>vsub</var> is 1.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>max_glyph_w</samp>’</dt>
|
|
<dd><p>maximum glyph width, that is the maximum width for all the glyphs
|
|
contained in the rendered text
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>max_glyph_h</samp>’</dt>
|
|
<dd><p>maximum glyph height, that is the maximum height for all the glyphs
|
|
contained in the rendered text, it is equivalent to <var>ascent</var> -
|
|
<var>descent</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>max_glyph_a, ascent</samp>’</dt>
|
|
<dd>
|
|
<p>the maximum distance from the baseline to the highest/upper grid
|
|
coordinate used to place a glyph outline point, for all the rendered
|
|
glyphs.
|
|
It is a positive value, due to the grid’s orientation with the Y axis
|
|
upwards.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>max_glyph_d, descent</samp>’</dt>
|
|
<dd><p>the maximum distance from the baseline to the lowest grid coordinate
|
|
used to place a glyph outline point, for all the rendered glyphs.
|
|
This is a negative value, due to the grid’s orientation, with the Y axis
|
|
upwards.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>n</samp>’</dt>
|
|
<dd><p>the number of input frame, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>t</samp>’</dt>
|
|
<dd><p>timestamp expressed in seconds, NAN if the input timestamp is unknown
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>timecode</samp>’</dt>
|
|
<dd><p>initial timecode representation in "hh:mm:ss[:;.]ff" format. It can be used
|
|
with or without text parameter. <var>rate</var> option must be specified.
|
|
Note that timecode options are <em>not</em> effective if FFmpeg is build with
|
|
<code>--disable-avcodec</code>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>r, rate</samp>’</dt>
|
|
<dd><p>frame rate (timecode only)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Some examples follow.
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
Draw "Test Text" with font FreeSerif, using the default values for the
|
|
optional parameters.
|
|
|
|
<table><tr><td> </td><td><pre class="example">drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Draw ’Test Text’ with font FreeSerif of size 24 at position x=100
|
|
and y=50 (counting from the top-left corner of the screen), text is
|
|
yellow with a red box around it. Both the text and the box have an
|
|
opacity of 20%.
|
|
|
|
<table><tr><td> </td><td><pre class="example">drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
|
|
x=100: y=50: fontsize=24: fontcolor=yellow@0.2: box=1: boxcolor=red@0.2"
|
|
</pre></td></tr></table>
|
|
|
|
<p>Note that the double quotes are not necessary if spaces are not used
|
|
within the parameter list.
|
|
</p>
|
|
</li><li>
|
|
Show the text at the center of the video frame:
|
|
<table><tr><td> </td><td><pre class="example">drawtext=fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h-line_h)/2"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Show a text line sliding from right to left in the last row of the video
|
|
frame. The file ‘<tt>LONG_LINE</tt>’ is assumed to contain a single line
|
|
with no newlines.
|
|
<table><tr><td> </td><td><pre class="example">drawtext=fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Show the content of file ‘<tt>CREDITS</tt>’ off the bottom of the frame and scroll up.
|
|
<table><tr><td> </td><td><pre class="example">drawtext=fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Draw a single green letter "g", at the center of the input video.
|
|
The glyph baseline is placed at half screen height.
|
|
<table><tr><td> </td><td><pre class="example">drawtext=fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent
|
|
</pre></td></tr></table>
|
|
|
|
</li></ul>
|
|
|
|
<p>For more information about libfreetype, check:
|
|
<a href="http://www.freetype.org/">http://www.freetype.org/</a>.
|
|
</p>
|
|
<a name="fade"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-fade">24.11 fade</a></h2>
|
|
|
|
<p>Apply fade-in/out effect to input video.
|
|
</p>
|
|
<p>It accepts the parameters:
|
|
<var>type</var>:<var>start_frame</var>:<var>nb_frames</var>[:<var>options</var>]
|
|
</p>
|
|
<p><var>type</var> specifies if the effect type, can be either "in" for
|
|
fade-in, or "out" for a fade-out effect.
|
|
</p>
|
|
<p><var>start_frame</var> specifies the number of the start frame for starting
|
|
to apply the fade effect.
|
|
</p>
|
|
<p><var>nb_frames</var> specifies the number of frames for which the fade
|
|
effect has to last. At the end of the fade-in effect the output video
|
|
will have the same intensity as the input video, at the end of the
|
|
fade-out transition the output video will be completely black.
|
|
</p>
|
|
<p><var>options</var> is an optional sequence of <var>key</var>=<var>value</var> pairs,
|
|
separated by ":". The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>type, t</samp>’</dt>
|
|
<dd><p>See <var>type</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>start_frame, s</samp>’</dt>
|
|
<dd><p>See <var>start_frame</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>nb_frames, n</samp>’</dt>
|
|
<dd><p>See <var>nb_frames</var>.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>alpha</samp>’</dt>
|
|
<dd><p>If set to 1, fade only alpha channel, if one exists on the input.
|
|
Default value is 0.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>A few usage examples follow, usable too as test scenarios.
|
|
</p><table><tr><td> </td><td><pre class="example"># fade in first 30 frames of video
|
|
fade=in:0:30
|
|
|
|
# fade out last 45 frames of a 200-frame video
|
|
fade=out:155:45
|
|
|
|
# fade in first 25 frames and fade out last 25 frames of a 1000-frame video
|
|
fade=in:0:25, fade=out:975:25
|
|
|
|
# make first 5 frames black, then fade in from frame 5-24
|
|
fade=in:5:20
|
|
|
|
# fade in alpha over first 25 frames of video
|
|
fade=in:0:25:alpha=1
|
|
</pre></td></tr></table>
|
|
|
|
<a name="fieldorder"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-fieldorder">24.12 fieldorder</a></h2>
|
|
|
|
<p>Transform the field order of the input video.
|
|
</p>
|
|
<p>It accepts one parameter which specifies the required field order that
|
|
the input interlaced video will be transformed to. The parameter can
|
|
assume one of the following values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>0 or bff</samp>’</dt>
|
|
<dd><p>output bottom field first
|
|
</p></dd>
|
|
<dt> ‘<samp>1 or tff</samp>’</dt>
|
|
<dd><p>output top field first
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is "tff".
|
|
</p>
|
|
<p>Transformation is achieved by shifting the picture content up or down
|
|
by one line, and filling the remaining line with appropriate picture content.
|
|
This method is consistent with most broadcast field order converters.
|
|
</p>
|
|
<p>If the input video is not flagged as being interlaced, or it is already
|
|
flagged as being of the required output field order then this filter does
|
|
not alter the incoming video.
|
|
</p>
|
|
<p>This filter is very useful when converting to or from PAL DV material,
|
|
which is bottom field first.
|
|
</p>
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
|
|
</pre></td></tr></table>
|
|
|
|
<a name="fifo"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-fifo">24.13 fifo</a></h2>
|
|
|
|
<p>Buffer input images and send them when they are requested.
|
|
</p>
|
|
<p>This filter is mainly useful when auto-inserted by the libavfilter
|
|
framework.
|
|
</p>
|
|
<p>The filter does not take parameters.
|
|
</p>
|
|
<a name="format"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-format">24.14 format</a></h2>
|
|
|
|
<p>Convert the input video to one of the specified pixel formats.
|
|
Libavfilter will try to pick one that is supported for the input to
|
|
the next filter.
|
|
</p>
|
|
<p>The filter accepts a list of pixel format names, separated by ":",
|
|
for example "yuv420p:monow:rgb24".
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># convert the input video to the format "yuv420p"
|
|
format=yuv420p
|
|
|
|
# convert the input video to any of the formats in the list
|
|
format=yuv420p:yuv444p:yuv410p
|
|
</pre></td></tr></table>
|
|
|
|
<p><a name="frei0r"></a>
|
|
</p><a name="frei0r-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-frei0r-1">24.15 frei0r</a></h2>
|
|
|
|
<p>Apply a frei0r effect to the input video.
|
|
</p>
|
|
<p>To enable compilation of this filter you need to install the frei0r
|
|
header and configure FFmpeg with <code>--enable-frei0r</code>.
|
|
</p>
|
|
<p>The filter supports the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example"><var>filter_name</var>[{:|=}<var>param1</var>:<var>param2</var>:...:<var>paramN</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p><var>filter_name</var> is the name to the frei0r effect to load. If the
|
|
environment variable <code>FREI0R_PATH</code> is defined, the frei0r effect
|
|
is searched in each one of the directories specified by the colon
|
|
separated list in <code>FREIOR_PATH</code>, otherwise in the standard frei0r
|
|
paths, which are in this order: ‘<tt>HOME/.frei0r-1/lib/</tt>’,
|
|
‘<tt>/usr/local/lib/frei0r-1/</tt>’, ‘<tt>/usr/lib/frei0r-1/</tt>’.
|
|
</p>
|
|
<p><var>param1</var>, <var>param2</var>, ... , <var>paramN</var> specify the parameters
|
|
for the frei0r effect.
|
|
</p>
|
|
<p>A frei0r effect parameter can be a boolean (whose values are specified
|
|
with "y" and "n"), a double, a color (specified by the syntax
|
|
<var>R</var>/<var>G</var>/<var>B</var>, <var>R</var>, <var>G</var>, and <var>B</var> being float
|
|
numbers from 0.0 to 1.0) or by an <code>av_parse_color()</code> color
|
|
description), a position (specified by the syntax <var>X</var>/<var>Y</var>,
|
|
<var>X</var> and <var>Y</var> being float numbers) and a string.
|
|
</p>
|
|
<p>The number and kind of parameters depend on the loaded effect. If an
|
|
effect parameter is not specified the default value is set.
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># apply the distort0r effect, set the first two double parameters
|
|
frei0r=distort0r:0.5:0.01
|
|
|
|
# apply the colordistance effect, takes a color as first parameter
|
|
frei0r=colordistance:0.2/0.3/0.4
|
|
frei0r=colordistance:violet
|
|
frei0r=colordistance:0x112233
|
|
|
|
# apply the perspective effect, specify the top left and top right
|
|
# image positions
|
|
frei0r=perspective:0.2/0.2:0.8/0.2
|
|
</pre></td></tr></table>
|
|
|
|
<p>For more information see:
|
|
<a href="http://piksel.org/frei0r">http://piksel.org/frei0r</a>
|
|
</p>
|
|
<a name="gradfun"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-gradfun">24.16 gradfun</a></h2>
|
|
|
|
<p>Fix the banding artifacts that are sometimes introduced into nearly flat
|
|
regions by truncation to 8bit color depth.
|
|
Interpolate the gradients that should go where the bands are, and
|
|
dither them.
|
|
</p>
|
|
<p>This filter is designed for playback only. Do not use it prior to
|
|
lossy compression, because compression tends to lose the dither and
|
|
bring back the bands.
|
|
</p>
|
|
<p>The filter takes two optional parameters, separated by ’:’:
|
|
<var>strength</var>:<var>radius</var>
|
|
</p>
|
|
<p><var>strength</var> is the maximum amount by which the filter will change
|
|
any one pixel. Also the threshold for detecting nearly flat
|
|
regions. Acceptable values range from .51 to 255, default value is
|
|
1.2, out-of-range values will be clipped to the valid range.
|
|
</p>
|
|
<p><var>radius</var> is the neighborhood to fit the gradient to. A larger
|
|
radius makes for smoother gradients, but also prevents the filter from
|
|
modifying the pixels near detailed regions. Acceptable values are
|
|
8-32, default value is 16, out-of-range values will be clipped to the
|
|
valid range.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example"># default parameters
|
|
gradfun=1.2:16
|
|
|
|
# omitting radius
|
|
gradfun=1.2
|
|
</pre></td></tr></table>
|
|
|
|
<a name="hflip"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-hflip">24.17 hflip</a></h2>
|
|
|
|
<p>Flip the input video horizontally.
|
|
</p>
|
|
<p>For example to horizontally flip the input video with <code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -vf "hflip" out.avi
|
|
</pre></td></tr></table>
|
|
|
|
<a name="hqdn3d"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-hqdn3d">24.18 hqdn3d</a></h2>
|
|
|
|
<p>High precision/quality 3d denoise filter. This filter aims to reduce
|
|
image noise producing smooth images and making still images really
|
|
still. It should enhance compressibility.
|
|
</p>
|
|
<p>It accepts the following optional parameters:
|
|
<var>luma_spatial</var>:<var>chroma_spatial</var>:<var>luma_tmp</var>:<var>chroma_tmp</var>
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>luma_spatial</samp>’</dt>
|
|
<dd><p>a non-negative float number which specifies spatial luma strength,
|
|
defaults to 4.0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>chroma_spatial</samp>’</dt>
|
|
<dd><p>a non-negative float number which specifies spatial chroma strength,
|
|
defaults to 3.0*<var>luma_spatial</var>/4.0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>luma_tmp</samp>’</dt>
|
|
<dd><p>a float number which specifies luma temporal strength, defaults to
|
|
6.0*<var>luma_spatial</var>/4.0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>chroma_tmp</samp>’</dt>
|
|
<dd><p>a float number which specifies chroma temporal strength, defaults to
|
|
<var>luma_tmp</var>*<var>chroma_spatial</var>/<var>luma_spatial</var>
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="lut_002c-lutrgb_002c-lutyuv"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-lut_002c-lutrgb_002c-lutyuv">24.19 lut, lutrgb, lutyuv</a></h2>
|
|
|
|
<p>Compute a look-up table for binding each pixel component input value
|
|
to an output value, and apply it to input video.
|
|
</p>
|
|
<p><var>lutyuv</var> applies a lookup table to a YUV input video, <var>lutrgb</var>
|
|
to an RGB input video.
|
|
</p>
|
|
<p>These filters accept in input a ":"-separated list of options, which
|
|
specify the expressions used for computing the lookup table for the
|
|
corresponding pixel component values.
|
|
</p>
|
|
<p>The <var>lut</var> filter requires either YUV or RGB pixel formats in
|
|
input, and accepts the options:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>c0</samp>’</dt>
|
|
<dd><p>first pixel component
|
|
</p></dd>
|
|
<dt> ‘<samp>c1</samp>’</dt>
|
|
<dd><p>second pixel component
|
|
</p></dd>
|
|
<dt> ‘<samp>c2</samp>’</dt>
|
|
<dd><p>third pixel component
|
|
</p></dd>
|
|
<dt> ‘<samp>c3</samp>’</dt>
|
|
<dd><p>fourth pixel component, corresponds to the alpha component
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The exact component associated to each option depends on the format in
|
|
input.
|
|
</p>
|
|
<p>The <var>lutrgb</var> filter requires RGB pixel formats in input, and
|
|
accepts the options:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>r</samp>’</dt>
|
|
<dd><p>red component
|
|
</p></dd>
|
|
<dt> ‘<samp>g</samp>’</dt>
|
|
<dd><p>green component
|
|
</p></dd>
|
|
<dt> ‘<samp>b</samp>’</dt>
|
|
<dd><p>blue component
|
|
</p></dd>
|
|
<dt> ‘<samp>a</samp>’</dt>
|
|
<dd><p>alpha component
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The <var>lutyuv</var> filter requires YUV pixel formats in input, and
|
|
accepts the options:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>y</samp>’</dt>
|
|
<dd><p>Y/luminance component
|
|
</p></dd>
|
|
<dt> ‘<samp>u</samp>’</dt>
|
|
<dd><p>U/Cb component
|
|
</p></dd>
|
|
<dt> ‘<samp>v</samp>’</dt>
|
|
<dd><p>V/Cr component
|
|
</p></dd>
|
|
<dt> ‘<samp>a</samp>’</dt>
|
|
<dd><p>alpha component
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The expressions can contain the following constants and functions:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>w, h</samp>’</dt>
|
|
<dd><p>the input width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>val</samp>’</dt>
|
|
<dd><p>input value for the pixel component
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>clipval</samp>’</dt>
|
|
<dd><p>the input value clipped in the <var>minval</var>-<var>maxval</var> range
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>maxval</samp>’</dt>
|
|
<dd><p>maximum value for the pixel component
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>minval</samp>’</dt>
|
|
<dd><p>minimum value for the pixel component
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>negval</samp>’</dt>
|
|
<dd><p>the negated value for the pixel component value clipped in the
|
|
<var>minval</var>-<var>maxval</var> range , it corresponds to the expression
|
|
"maxval-clipval+minval"
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>clip(val)</samp>’</dt>
|
|
<dd><p>the computed value in <var>val</var> clipped in the
|
|
<var>minval</var>-<var>maxval</var> range
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>gammaval(gamma)</samp>’</dt>
|
|
<dd><p>the computed gamma correction value of the pixel component value
|
|
clipped in the <var>minval</var>-<var>maxval</var> range, corresponds to the
|
|
expression
|
|
"pow((clipval-minval)/(maxval-minval)\,<var>gamma</var>)*(maxval-minval)+minval"
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>All expressions default to "val".
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># negate input video
|
|
lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
|
|
lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
|
|
|
|
# the above is the same as
|
|
lutrgb="r=negval:g=negval:b=negval"
|
|
lutyuv="y=negval:u=negval:v=negval"
|
|
|
|
# negate luminance
|
|
lutyuv=y=negval
|
|
|
|
# remove chroma components, turns the video into a graytone image
|
|
lutyuv="u=128:v=128"
|
|
|
|
# apply a luma burning effect
|
|
lutyuv="y=2*val"
|
|
|
|
# remove green and blue components
|
|
lutrgb="g=0:b=0"
|
|
|
|
# set a constant alpha channel value on input
|
|
format=rgba,lutrgb=a="maxval-minval/2"
|
|
|
|
# correct luminance gamma by a 0.5 factor
|
|
lutyuv=y=gammaval(0.5)
|
|
</pre></td></tr></table>
|
|
|
|
<a name="mp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mp">24.20 mp</a></h2>
|
|
|
|
<p>Apply an MPlayer filter to the input video.
|
|
</p>
|
|
<p>This filter provides a wrapper around most of the filters of
|
|
MPlayer/MEncoder.
|
|
</p>
|
|
<p>This wrapper is considered experimental. Some of the wrapped filters
|
|
may not work properly and we may drop support for them, as they will
|
|
be implemented natively into FFmpeg. Thus you should avoid
|
|
depending on them when writing portable scripts.
|
|
</p>
|
|
<p>The filters accepts the parameters:
|
|
<var>filter_name</var>[:=]<var>filter_params</var>
|
|
</p>
|
|
<p><var>filter_name</var> is the name of a supported MPlayer filter,
|
|
<var>filter_params</var> is a string containing the parameters accepted by
|
|
the named filter.
|
|
</p>
|
|
<p>The list of the currently supported filters follows:
|
|
</p><dl compact="compact">
|
|
<dt> <var>2xsai</var></dt>
|
|
<dt> <var>decimate</var></dt>
|
|
<dt> <var>denoise3d</var></dt>
|
|
<dt> <var>detc</var></dt>
|
|
<dt> <var>dint</var></dt>
|
|
<dt> <var>divtc</var></dt>
|
|
<dt> <var>down3dright</var></dt>
|
|
<dt> <var>dsize</var></dt>
|
|
<dt> <var>eq2</var></dt>
|
|
<dt> <var>eq</var></dt>
|
|
<dt> <var>field</var></dt>
|
|
<dt> <var>fil</var></dt>
|
|
<dt> <var>fixpts</var></dt>
|
|
<dt> <var>framestep</var></dt>
|
|
<dt> <var>fspp</var></dt>
|
|
<dt> <var>geq</var></dt>
|
|
<dt> <var>harddup</var></dt>
|
|
<dt> <var>hqdn3d</var></dt>
|
|
<dt> <var>hue</var></dt>
|
|
<dt> <var>il</var></dt>
|
|
<dt> <var>ilpack</var></dt>
|
|
<dt> <var>ivtc</var></dt>
|
|
<dt> <var>kerndeint</var></dt>
|
|
<dt> <var>mcdeint</var></dt>
|
|
<dt> <var>mirror</var></dt>
|
|
<dt> <var>noise</var></dt>
|
|
<dt> <var>ow</var></dt>
|
|
<dt> <var>palette</var></dt>
|
|
<dt> <var>perspective</var></dt>
|
|
<dt> <var>phase</var></dt>
|
|
<dt> <var>pp7</var></dt>
|
|
<dt> <var>pullup</var></dt>
|
|
<dt> <var>qp</var></dt>
|
|
<dt> <var>rectangle</var></dt>
|
|
<dt> <var>remove-logo</var></dt>
|
|
<dt> <var>rotate</var></dt>
|
|
<dt> <var>sab</var></dt>
|
|
<dt> <var>screenshot</var></dt>
|
|
<dt> <var>smartblur</var></dt>
|
|
<dt> <var>softpulldown</var></dt>
|
|
<dt> <var>softskip</var></dt>
|
|
<dt> <var>spp</var></dt>
|
|
<dt> <var>swapuv</var></dt>
|
|
<dt> <var>telecine</var></dt>
|
|
<dt> <var>tile</var></dt>
|
|
<dt> <var>tinterlace</var></dt>
|
|
<dt> <var>unsharp</var></dt>
|
|
<dt> <var>uspp</var></dt>
|
|
<dt> <var>yuvcsp</var></dt>
|
|
<dt> <var>yvu9</var></dt>
|
|
</dl>
|
|
|
|
<p>The parameter syntax and behavior for the listed filters are the same
|
|
of the corresponding MPlayer filters. For detailed instructions check
|
|
the "VIDEO FILTERS" section in the MPlayer manual.
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># remove a logo by interpolating the surrounding pixels
|
|
mp=delogo=200:200:80:20:1
|
|
|
|
# adjust gamma, brightness, contrast
|
|
mp=eq2=1.0:2:0.5
|
|
|
|
# tweak hue and saturation
|
|
mp=hue=100:-10
|
|
</pre></td></tr></table>
|
|
|
|
<p>See also mplayer(1), <a href="http://www.mplayerhq.hu/">http://www.mplayerhq.hu/</a>.
|
|
</p>
|
|
<a name="negate"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-negate">24.21 negate</a></h2>
|
|
|
|
<p>Negate input video.
|
|
</p>
|
|
<p>This filter accepts an integer in input, if non-zero it negates the
|
|
alpha component (if available). The default value in input is 0.
|
|
</p>
|
|
<a name="noformat"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-noformat">24.22 noformat</a></h2>
|
|
|
|
<p>Force libavfilter not to use any of the specified pixel formats for the
|
|
input to the next filter.
|
|
</p>
|
|
<p>The filter accepts a list of pixel format names, separated by ":",
|
|
for example "yuv420p:monow:rgb24".
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># force libavfilter to use a format different from "yuv420p" for the
|
|
# input to the vflip filter
|
|
noformat=yuv420p,vflip
|
|
|
|
# convert the input video to any of the formats not contained in the list
|
|
noformat=yuv420p:yuv444p:yuv410p
|
|
</pre></td></tr></table>
|
|
|
|
<a name="null-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-null-1">24.23 null</a></h2>
|
|
|
|
<p>Pass the video source unchanged to the output.
|
|
</p>
|
|
<a name="ocv"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-ocv">24.24 ocv</a></h2>
|
|
|
|
<p>Apply video transform using libopencv.
|
|
</p>
|
|
<p>To enable this filter install libopencv library and headers and
|
|
configure FFmpeg with <code>--enable-libopencv</code>.
|
|
</p>
|
|
<p>The filter takes the parameters: <var>filter_name</var>{:=}<var>filter_params</var>.
|
|
</p>
|
|
<p><var>filter_name</var> is the name of the libopencv filter to apply.
|
|
</p>
|
|
<p><var>filter_params</var> specifies the parameters to pass to the libopencv
|
|
filter. If not specified the default values are assumed.
|
|
</p>
|
|
<p>Refer to the official libopencv documentation for more precise
|
|
information:
|
|
<a href="http://opencv.willowgarage.com/documentation/c/image_filtering.html">http://opencv.willowgarage.com/documentation/c/image_filtering.html</a>
|
|
</p>
|
|
<p>Follows the list of supported libopencv filters.
|
|
</p>
|
|
<p><a name="dilate"></a>
|
|
</p><a name="dilate-1"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-dilate-1">24.24.1 dilate</a></h3>
|
|
|
|
<p>Dilate an image by using a specific structuring element.
|
|
This filter corresponds to the libopencv function <code>cvDilate</code>.
|
|
</p>
|
|
<p>It accepts the parameters: <var>struct_el</var>:<var>nb_iterations</var>.
|
|
</p>
|
|
<p><var>struct_el</var> represents a structuring element, and has the syntax:
|
|
<var>cols</var>x<var>rows</var>+<var>anchor_x</var>x<var>anchor_y</var>/<var>shape</var>
|
|
</p>
|
|
<p><var>cols</var> and <var>rows</var> represent the number of columns and rows of
|
|
the structuring element, <var>anchor_x</var> and <var>anchor_y</var> the anchor
|
|
point, and <var>shape</var> the shape for the structuring element, and
|
|
can be one of the values "rect", "cross", "ellipse", "custom".
|
|
</p>
|
|
<p>If the value for <var>shape</var> is "custom", it must be followed by a
|
|
string of the form "=<var>filename</var>". The file with name
|
|
<var>filename</var> is assumed to represent a binary image, with each
|
|
printable character corresponding to a bright pixel. When a custom
|
|
<var>shape</var> is used, <var>cols</var> and <var>rows</var> are ignored, the number
|
|
or columns and rows of the read file are assumed instead.
|
|
</p>
|
|
<p>The default value for <var>struct_el</var> is "3x3+0x0/rect".
|
|
</p>
|
|
<p><var>nb_iterations</var> specifies the number of times the transform is
|
|
applied to the image, and defaults to 1.
|
|
</p>
|
|
<p>Follow some example:
|
|
</p><table><tr><td> </td><td><pre class="example"># use the default values
|
|
ocv=dilate
|
|
|
|
# dilate using a structuring element with a 5x5 cross, iterate two times
|
|
ocv=dilate=5x5+2x2/cross:2
|
|
|
|
# read the shape from the file diamond.shape, iterate two times
|
|
# the file diamond.shape may contain a pattern of characters like this:
|
|
# *
|
|
# ***
|
|
# *****
|
|
# ***
|
|
# *
|
|
# the specified cols and rows are ignored (but not the anchor point coordinates)
|
|
ocv=0x0+2x2/custom=diamond.shape:2
|
|
</pre></td></tr></table>
|
|
|
|
<a name="erode"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-erode">24.24.2 erode</a></h3>
|
|
|
|
<p>Erode an image by using a specific structuring element.
|
|
This filter corresponds to the libopencv function <code>cvErode</code>.
|
|
</p>
|
|
<p>The filter accepts the parameters: <var>struct_el</var>:<var>nb_iterations</var>,
|
|
with the same syntax and semantics as the <a href="#dilate">dilate</a> filter.
|
|
</p>
|
|
<a name="smooth"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-smooth">24.24.3 smooth</a></h3>
|
|
|
|
<p>Smooth the input video.
|
|
</p>
|
|
<p>The filter takes the following parameters:
|
|
<var>type</var>:<var>param1</var>:<var>param2</var>:<var>param3</var>:<var>param4</var>.
|
|
</p>
|
|
<p><var>type</var> is the type of smooth filter to apply, and can be one of
|
|
the following values: "blur", "blur_no_scale", "median", "gaussian",
|
|
"bilateral". The default value is "gaussian".
|
|
</p>
|
|
<p><var>param1</var>, <var>param2</var>, <var>param3</var>, and <var>param4</var> are
|
|
parameters whose meanings depend on smooth type. <var>param1</var> and
|
|
<var>param2</var> accept integer positive values or 0, <var>param3</var> and
|
|
<var>param4</var> accept float values.
|
|
</p>
|
|
<p>The default value for <var>param1</var> is 3, the default value for the
|
|
other parameters is 0.
|
|
</p>
|
|
<p>These parameters correspond to the parameters assigned to the
|
|
libopencv function <code>cvSmooth</code>.
|
|
</p>
|
|
<p><a name="overlay"></a>
|
|
</p><a name="overlay-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-overlay-1">24.25 overlay</a></h2>
|
|
|
|
<p>Overlay one video on top of another.
|
|
</p>
|
|
<p>It takes two inputs and one output, the first input is the "main"
|
|
video on which the second input is overlayed.
|
|
</p>
|
|
<p>It accepts the parameters: <var>x</var>:<var>y</var>[:<var>options</var>].
|
|
</p>
|
|
<p><var>x</var> is the x coordinate of the overlayed video on the main video,
|
|
<var>y</var> is the y coordinate. <var>x</var> and <var>y</var> are expressions containing
|
|
the following parameters:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>main_w, main_h</samp>’</dt>
|
|
<dd><p>main input width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>W, H</samp>’</dt>
|
|
<dd><p>same as <var>main_w</var> and <var>main_h</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>overlay_w, overlay_h</samp>’</dt>
|
|
<dd><p>overlay input width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>w, h</samp>’</dt>
|
|
<dd><p>same as <var>overlay_w</var> and <var>overlay_h</var>
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p><var>options</var> is an optional list of <var>key</var>=<var>value</var> pairs,
|
|
separated by ":".
|
|
</p>
|
|
<p>The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>rgb</samp>’</dt>
|
|
<dd><p>If set to 1, force the filter to accept inputs in the RGB
|
|
color space. Default value is 0.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Be aware that frames are taken from each input video in timestamp
|
|
order, hence, if their initial timestamps differ, it is a a good idea
|
|
to pass the two inputs through a <var>setpts=PTS-STARTPTS</var> filter to
|
|
have them begin in the same zero timestamp, as it does the example for
|
|
the <var>movie</var> filter.
|
|
</p>
|
|
<p>Follow some examples:
|
|
</p><table><tr><td> </td><td><pre class="example"># draw the overlay at 10 pixels from the bottom right
|
|
# corner of the main video.
|
|
overlay=main_w-overlay_w-10:main_h-overlay_h-10
|
|
|
|
# insert a transparent PNG logo in the bottom left corner of the input
|
|
movie=logo.png [logo];
|
|
[in][logo] overlay=10:main_h-overlay_h-10 [out]
|
|
|
|
# insert 2 different transparent PNG logos (second logo on bottom
|
|
# right corner):
|
|
movie=logo1.png [logo1];
|
|
movie=logo2.png [logo2];
|
|
[in][logo1] overlay=10:H-h-10 [in+logo1];
|
|
[in+logo1][logo2] overlay=W-w-10:H-h-10 [out]
|
|
|
|
# add a transparent color layer on top of the main video,
|
|
# WxH specifies the size of the main input to the overlay filter
|
|
color=red.3:WxH [over]; [in][over] overlay [out]
|
|
</pre></td></tr></table>
|
|
|
|
<p>You can chain together more overlays but the efficiency of such
|
|
approach is yet to be tested.
|
|
</p>
|
|
<a name="pad"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-pad">24.26 pad</a></h2>
|
|
|
|
<p>Add paddings to the input image, and places the original input at the
|
|
given coordinates <var>x</var>, <var>y</var>.
|
|
</p>
|
|
<p>It accepts the following parameters:
|
|
<var>width</var>:<var>height</var>:<var>x</var>:<var>y</var>:<var>color</var>.
|
|
</p>
|
|
<p>The parameters <var>width</var>, <var>height</var>, <var>x</var>, and <var>y</var> are
|
|
expressions containing the following constants:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>in_w, in_h</samp>’</dt>
|
|
<dd><p>the input video width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>iw, ih</samp>’</dt>
|
|
<dd><p>same as <var>in_w</var> and <var>in_h</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>out_w, out_h</samp>’</dt>
|
|
<dd><p>the output width and height, that is the size of the padded area as
|
|
specified by the <var>width</var> and <var>height</var> expressions
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ow, oh</samp>’</dt>
|
|
<dd><p>same as <var>out_w</var> and <var>out_h</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>x, y</samp>’</dt>
|
|
<dd><p>x and y offsets as specified by the <var>x</var> and <var>y</var>
|
|
expressions, or NAN if not yet specified
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>a</samp>’</dt>
|
|
<dd><p>same as <var>iw</var> / <var>ih</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sar</samp>’</dt>
|
|
<dd><p>input sample aspect ratio
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>dar</samp>’</dt>
|
|
<dd><p>input display aspect ratio, it is the same as (<var>iw</var> / <var>ih</var>) * <var>sar</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>hsub, vsub</samp>’</dt>
|
|
<dd><p>horizontal and vertical chroma subsample values. For example for the
|
|
pixel format "yuv422p" <var>hsub</var> is 2 and <var>vsub</var> is 1.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Follows the description of the accepted parameters.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>width, height</samp>’</dt>
|
|
<dd>
|
|
<p>Specify the size of the output image with the paddings added. If the
|
|
value for <var>width</var> or <var>height</var> is 0, the corresponding input size
|
|
is used for the output.
|
|
</p>
|
|
<p>The <var>width</var> expression can reference the value set by the
|
|
<var>height</var> expression, and vice versa.
|
|
</p>
|
|
<p>The default value of <var>width</var> and <var>height</var> is 0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>x, y</samp>’</dt>
|
|
<dd>
|
|
<p>Specify the offsets where to place the input image in the padded area
|
|
with respect to the top/left border of the output image.
|
|
</p>
|
|
<p>The <var>x</var> expression can reference the value set by the <var>y</var>
|
|
expression, and vice versa.
|
|
</p>
|
|
<p>The default value of <var>x</var> and <var>y</var> is 0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>color</samp>’</dt>
|
|
<dd>
|
|
<p>Specify the color of the padded area, it can be the name of a color
|
|
(case insensitive match) or a 0xRRGGBB[AA] sequence.
|
|
</p>
|
|
<p>The default value of <var>color</var> is "black".
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>Some examples follow:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example"># Add paddings with color "violet" to the input video. Output video
|
|
# size is 640x480, the top-left corner of the input video is placed at
|
|
# column 0, row 40.
|
|
pad=640:480:0:40:violet
|
|
|
|
# pad the input to get an output with dimensions increased bt 3/2,
|
|
# and put the input video at the center of the padded area
|
|
pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
|
|
|
|
# pad the input to get a squared output with size equal to the maximum
|
|
# value between the input width and height, and put the input video at
|
|
# the center of the padded area
|
|
pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
|
|
|
|
# pad the input to get a final w/h ratio of 16:9
|
|
pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
|
|
|
|
# for anamorphic video, in order to set the output display aspect ratio,
|
|
# it is necessary to use sar in the expression, according to the relation:
|
|
# (ih * X / ih) * sar = output_dar
|
|
# X = output_dar / sar
|
|
pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
|
|
|
|
# double output size and put the input video in the bottom-right
|
|
# corner of the output padded area
|
|
pad="2*iw:2*ih:ow-iw:oh-ih"
|
|
</pre></td></tr></table>
|
|
|
|
<a name="pixdesctest"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-pixdesctest">24.27 pixdesctest</a></h2>
|
|
|
|
<p>Pixel format descriptor test filter, mainly useful for internal
|
|
testing. The output video should be equal to the input video.
|
|
</p>
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">format=monow, pixdesctest
|
|
</pre></td></tr></table>
|
|
|
|
<p>can be used to test the monowhite pixel format descriptor definition.
|
|
</p>
|
|
<a name="scale"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-scale">24.28 scale</a></h2>
|
|
|
|
<p>Scale the input video to <var>width</var>:<var>height</var>[:<var>interl</var>={1|-1}] and/or convert the image format.
|
|
</p>
|
|
<p>The parameters <var>width</var> and <var>height</var> are expressions containing
|
|
the following constants:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>in_w, in_h</samp>’</dt>
|
|
<dd><p>the input width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>iw, ih</samp>’</dt>
|
|
<dd><p>same as <var>in_w</var> and <var>in_h</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>out_w, out_h</samp>’</dt>
|
|
<dd><p>the output (cropped) width and height
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>ow, oh</samp>’</dt>
|
|
<dd><p>same as <var>out_w</var> and <var>out_h</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>a</samp>’</dt>
|
|
<dd><p>same as <var>iw</var> / <var>ih</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sar</samp>’</dt>
|
|
<dd><p>input sample aspect ratio
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>dar</samp>’</dt>
|
|
<dd><p>input display aspect ratio, it is the same as (<var>iw</var> / <var>ih</var>) * <var>sar</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>hsub, vsub</samp>’</dt>
|
|
<dd><p>horizontal and vertical chroma subsample values. For example for the
|
|
pixel format "yuv422p" <var>hsub</var> is 2 and <var>vsub</var> is 1.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>If the input image format is different from the format requested by
|
|
the next filter, the scale filter will convert the input to the
|
|
requested format.
|
|
</p>
|
|
<p>If the value for <var>width</var> or <var>height</var> is 0, the respective input
|
|
size is used for the output.
|
|
</p>
|
|
<p>If the value for <var>width</var> or <var>height</var> is -1, the scale filter will
|
|
use, for the respective output size, a value that maintains the aspect
|
|
ratio of the input image.
|
|
</p>
|
|
<p>The default value of <var>width</var> and <var>height</var> is 0.
|
|
</p>
|
|
<p>Valid values for the optional parameter <var>interl</var> are:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>force interlaced aware scaling
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>-1</samp>’</dt>
|
|
<dd><p>select interlaced aware scaling depending on whether the source frames
|
|
are flagged as interlaced or not
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># scale the input video to a size of 200x100.
|
|
scale=200:100
|
|
|
|
# scale the input to 2x
|
|
scale=2*iw:2*ih
|
|
# the above is the same as
|
|
scale=2*in_w:2*in_h
|
|
|
|
# scale the input to half size
|
|
scale=iw/2:ih/2
|
|
|
|
# increase the width, and set the height to the same size
|
|
scale=3/2*iw:ow
|
|
|
|
# seek for Greek harmony
|
|
scale=iw:1/PHI*iw
|
|
scale=ih*PHI:ih
|
|
|
|
# increase the height, and set the width to 3/2 of the height
|
|
scale=3/2*oh:3/5*ih
|
|
|
|
# increase the size, but make the size a multiple of the chroma
|
|
scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
|
|
|
|
# increase the width to a maximum of 500 pixels, keep the same input aspect ratio
|
|
scale='min(500\, iw*3/2):-1'
|
|
</pre></td></tr></table>
|
|
|
|
<a name="select"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-select">24.29 select</a></h2>
|
|
<p>Select frames to pass in output.
|
|
</p>
|
|
<p>It accepts in input an expression, which is evaluated for each input
|
|
frame. If the expression is evaluated to a non-zero value, the frame
|
|
is selected and passed to the output, otherwise it is discarded.
|
|
</p>
|
|
<p>The expression can contain the following constants:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>n</samp>’</dt>
|
|
<dd><p>the sequential number of the filtered frame, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>selected_n</samp>’</dt>
|
|
<dd><p>the sequential number of the selected frame, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>prev_selected_n</samp>’</dt>
|
|
<dd><p>the sequential number of the last selected frame, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>TB</samp>’</dt>
|
|
<dd><p>timebase of the input timestamps
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pts</samp>’</dt>
|
|
<dd><p>the PTS (Presentation TimeStamp) of the filtered video frame,
|
|
expressed in <var>TB</var> units, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>t</samp>’</dt>
|
|
<dd><p>the PTS (Presentation TimeStamp) of the filtered video frame,
|
|
expressed in seconds, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>prev_pts</samp>’</dt>
|
|
<dd><p>the PTS of the previously filtered video frame, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>prev_selected_pts</samp>’</dt>
|
|
<dd><p>the PTS of the last previously filtered video frame, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>prev_selected_t</samp>’</dt>
|
|
<dd><p>the PTS of the last previously selected video frame, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>start_pts</samp>’</dt>
|
|
<dd><p>the PTS of the first video frame in the video, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>start_t</samp>’</dt>
|
|
<dd><p>the time of the first video frame in the video, NAN if undefined
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pict_type</samp>’</dt>
|
|
<dd><p>the type of the filtered frame, can assume one of the following
|
|
values:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>I</samp>’</dt>
|
|
<dt> ‘<samp>P</samp>’</dt>
|
|
<dt> ‘<samp>B</samp>’</dt>
|
|
<dt> ‘<samp>S</samp>’</dt>
|
|
<dt> ‘<samp>SI</samp>’</dt>
|
|
<dt> ‘<samp>SP</samp>’</dt>
|
|
<dt> ‘<samp>BI</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>interlace_type</samp>’</dt>
|
|
<dd><p>the frame interlace type, can assume one of the following values:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>PROGRESSIVE</samp>’</dt>
|
|
<dd><p>the frame is progressive (not interlaced)
|
|
</p></dd>
|
|
<dt> ‘<samp>TOPFIRST</samp>’</dt>
|
|
<dd><p>the frame is top-field-first
|
|
</p></dd>
|
|
<dt> ‘<samp>BOTTOMFIRST</samp>’</dt>
|
|
<dd><p>the frame is bottom-field-first
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>key</samp>’</dt>
|
|
<dd><p>1 if the filtered frame is a key-frame, 0 otherwise
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pos</samp>’</dt>
|
|
<dd><p>the position in the file of the filtered frame, -1 if the information
|
|
is not available (e.g. for synthetic video)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The default value of the select expression is "1".
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example"># select all frames in input
|
|
select
|
|
|
|
# the above is the same as:
|
|
select=1
|
|
|
|
# skip all frames:
|
|
select=0
|
|
|
|
# select only I-frames
|
|
select='eq(pict_type\,I)'
|
|
|
|
# select one frame every 100
|
|
select='not(mod(n\,100))'
|
|
|
|
# select only frames contained in the 10-20 time interval
|
|
select='gte(t\,10)*lte(t\,20)'
|
|
|
|
# select only I frames contained in the 10-20 time interval
|
|
select='gte(t\,10)*lte(t\,20)*eq(pict_type\,I)'
|
|
|
|
# select frames with a minimum distance of 10 seconds
|
|
select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
|
|
</pre></td></tr></table>
|
|
|
|
<p><a name="setdar"></a>
|
|
</p><a name="setdar-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-setdar-1">24.30 setdar</a></h2>
|
|
|
|
<p>Set the Display Aspect Ratio for the filter output video.
|
|
</p>
|
|
<p>This is done by changing the specified Sample (aka Pixel) Aspect
|
|
Ratio, according to the following equation:
|
|
<em>DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR</em>
|
|
</p>
|
|
<p>Keep in mind that this filter does not modify the pixel dimensions of
|
|
the video frame. Also the display aspect ratio set by this filter may
|
|
be changed by later filters in the filterchain, e.g. in case of
|
|
scaling or if another "setdar" or a "setsar" filter is applied.
|
|
</p>
|
|
<p>The filter accepts a parameter string which represents the wanted
|
|
display aspect ratio.
|
|
The parameter can be a floating point number string, or an expression
|
|
of the form <var>num</var>:<var>den</var>, where <var>num</var> and <var>den</var> are the
|
|
numerator and denominator of the aspect ratio.
|
|
If the parameter is not specified, it is assumed the value "0:1".
|
|
</p>
|
|
<p>For example to change the display aspect ratio to 16:9, specify:
|
|
</p><table><tr><td> </td><td><pre class="example">setdar=16:9
|
|
# the above is equivalent to
|
|
setdar=1.77777
|
|
</pre></td></tr></table>
|
|
|
|
<p>See also the <a href="#setsar">setsar</a> filter documentation.
|
|
</p>
|
|
<a name="setpts"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-setpts">24.31 setpts</a></h2>
|
|
|
|
<p>Change the PTS (presentation timestamp) of the input video frames.
|
|
</p>
|
|
<p>Accept in input an expression evaluated through the eval API, which
|
|
can contain the following constants:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>PTS</samp>’</dt>
|
|
<dd><p>the presentation timestamp in input
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>N</samp>’</dt>
|
|
<dd><p>the count of the input frame, starting from 0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>STARTPTS</samp>’</dt>
|
|
<dd><p>the PTS of the first video frame
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>INTERLACED</samp>’</dt>
|
|
<dd><p>tell if the current frame is interlaced
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>POS</samp>’</dt>
|
|
<dd><p>original position in the file of the frame, or undefined if undefined
|
|
for the current frame
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>PREV_INPTS</samp>’</dt>
|
|
<dd><p>previous input PTS
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>PREV_OUTPTS</samp>’</dt>
|
|
<dd><p>previous output PTS
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>Some examples follow:
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example"># start counting PTS from zero
|
|
setpts=PTS-STARTPTS
|
|
|
|
# fast motion
|
|
setpts=0.5*PTS
|
|
|
|
# slow motion
|
|
setpts=2.0*PTS
|
|
|
|
# fixed rate 25 fps
|
|
setpts=N/(25*TB)
|
|
|
|
# fixed rate 25 fps with some jitter
|
|
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
|
|
</pre></td></tr></table>
|
|
|
|
<p><a name="setsar"></a>
|
|
</p><a name="setsar-1"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-setsar-1">24.32 setsar</a></h2>
|
|
|
|
<p>Set the Sample (aka Pixel) Aspect Ratio for the filter output video.
|
|
</p>
|
|
<p>Note that as a consequence of the application of this filter, the
|
|
output display aspect ratio will change according to the following
|
|
equation:
|
|
<em>DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR</em>
|
|
</p>
|
|
<p>Keep in mind that the sample aspect ratio set by this filter may be
|
|
changed by later filters in the filterchain, e.g. if another "setsar"
|
|
or a "setdar" filter is applied.
|
|
</p>
|
|
<p>The filter accepts a parameter string which represents the wanted
|
|
sample aspect ratio.
|
|
The parameter can be a floating point number string, or an expression
|
|
of the form <var>num</var>:<var>den</var>, where <var>num</var> and <var>den</var> are the
|
|
numerator and denominator of the aspect ratio.
|
|
If the parameter is not specified, it is assumed the value "0:1".
|
|
</p>
|
|
<p>For example to change the sample aspect ratio to 10:11, specify:
|
|
</p><table><tr><td> </td><td><pre class="example">setsar=10:11
|
|
</pre></td></tr></table>
|
|
|
|
<a name="settb"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-settb">24.33 settb</a></h2>
|
|
|
|
<p>Set the timebase to use for the output frames timestamps.
|
|
It is mainly useful for testing timebase configuration.
|
|
</p>
|
|
<p>It accepts in input an arithmetic expression representing a rational.
|
|
The expression can contain the constants "AVTB" (the
|
|
default timebase), and "intb" (the input timebase).
|
|
</p>
|
|
<p>The default value for the input is "intb".
|
|
</p>
|
|
<p>Follow some examples.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example"># set the timebase to 1/25
|
|
settb=1/25
|
|
|
|
# set the timebase to 1/10
|
|
settb=0.1
|
|
|
|
#set the timebase to 1001/1000
|
|
settb=1+0.001
|
|
|
|
#set the timebase to 2*intb
|
|
settb=2*intb
|
|
|
|
#set the default timebase value
|
|
settb=AVTB
|
|
</pre></td></tr></table>
|
|
|
|
<a name="showinfo"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-showinfo">24.34 showinfo</a></h2>
|
|
|
|
<p>Show a line containing various information for each input video frame.
|
|
The input video is not modified.
|
|
</p>
|
|
<p>The shown line contains a sequence of key/value pairs of the form
|
|
<var>key</var>:<var>value</var>.
|
|
</p>
|
|
<p>A description of each shown parameter follows:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>n</samp>’</dt>
|
|
<dd><p>sequential number of the input frame, starting from 0
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pts</samp>’</dt>
|
|
<dd><p>Presentation TimeStamp of the input frame, expressed as a number of
|
|
time base units. The time base unit depends on the filter input pad.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pts_time</samp>’</dt>
|
|
<dd><p>Presentation TimeStamp of the input frame, expressed as a number of
|
|
seconds
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pos</samp>’</dt>
|
|
<dd><p>position of the frame in the input stream, -1 if this information in
|
|
unavailable and/or meaningless (for example in case of synthetic video)
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>fmt</samp>’</dt>
|
|
<dd><p>pixel format name
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sar</samp>’</dt>
|
|
<dd><p>sample aspect ratio of the input frame, expressed in the form
|
|
<var>num</var>/<var>den</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>s</samp>’</dt>
|
|
<dd><p>size of the input frame, expressed in the form
|
|
<var>width</var>x<var>height</var>
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>i</samp>’</dt>
|
|
<dd><p>interlaced mode ("P" for "progressive", "T" for top field first, "B"
|
|
for bottom field first)
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>iskey</samp>’</dt>
|
|
<dd><p>1 if the frame is a key frame, 0 otherwise
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>type</samp>’</dt>
|
|
<dd><p>picture type of the input frame ("I" for an I-frame, "P" for a
|
|
P-frame, "B" for a B-frame, "?" for unknown type).
|
|
Check also the documentation of the <code>AVPictureType</code> enum and of
|
|
the <code>av_get_picture_type_char</code> function defined in
|
|
‘<tt>libavutil/avutil.h</tt>’.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>checksum</samp>’</dt>
|
|
<dd><p>Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>plane_checksum</samp>’</dt>
|
|
<dd><p>Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
|
|
expressed in the form "[<var>c0</var> <var>c1</var> <var>c2</var> <var>c3</var>]"
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="slicify"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-slicify">24.35 slicify</a></h2>
|
|
|
|
<p>Pass the images of input video on to next video filter as multiple
|
|
slices.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -vf "slicify=32" out.avi
|
|
</pre></td></tr></table>
|
|
|
|
<p>The filter accepts the slice height as parameter. If the parameter is
|
|
not specified it will use the default value of 16.
|
|
</p>
|
|
<p>Adding this in the beginning of filter chains should make filtering
|
|
faster due to better use of the memory cache.
|
|
</p>
|
|
<a name="split"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-split">24.36 split</a></h2>
|
|
|
|
<p>Pass on the input video to two outputs. Both outputs are identical to
|
|
the input video.
|
|
</p>
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">[in] split [splitout1][splitout2];
|
|
[splitout1] crop=100:100:0:0 [cropout];
|
|
[splitout2] pad=200:200:100:100 [padout];
|
|
</pre></td></tr></table>
|
|
|
|
<p>will create two separate outputs from the same input, one cropped and
|
|
one padded.
|
|
</p>
|
|
<a name="thumbnail"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-thumbnail">24.37 thumbnail</a></h2>
|
|
<p>Select the most representative frame in a given sequence of consecutive frames.
|
|
</p>
|
|
<p>It accepts as argument the frames batch size to analyze (default <var>N</var>=100);
|
|
in a set of <var>N</var> frames, the filter will pick one of them, and then handle
|
|
the next batch of <var>N</var> frames until the end.
|
|
</p>
|
|
<p>Since the filter keeps track of the whole frames sequence, a bigger <var>N</var>
|
|
value will result in a higher memory usage, so a high value is not recommended.
|
|
</p>
|
|
<p>The following example extract one picture each 50 frames:
|
|
</p><table><tr><td> </td><td><pre class="example">thumbnail=50
|
|
</pre></td></tr></table>
|
|
|
|
<p>Complete example of a thumbnail creation with <code>ffmpeg</code>:
|
|
</p><table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
|
|
</pre></td></tr></table>
|
|
|
|
<a name="tinterlace"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-tinterlace">24.38 tinterlace</a></h2>
|
|
|
|
<p>Perform various types of temporal field interlacing.
|
|
</p>
|
|
<p>Frames are counted starting from 1, so the first input frame is
|
|
considered odd.
|
|
</p>
|
|
<p>This filter accepts a single parameter specifying the mode. Available
|
|
modes are:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>Move odd frames into the upper field, even into the lower field,
|
|
generating a double height frame at half framerate.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>Only output even frames, odd frames are dropped, generating a frame with
|
|
unchanged height at half framerate.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>Only output odd frames, even frames are dropped, generating a frame with
|
|
unchanged height at half framerate.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>3</samp>’</dt>
|
|
<dd><p>Expand each frame to full height, but pad alternate lines with black,
|
|
generating a frame with double height at the same input framerate.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>4</samp>’</dt>
|
|
<dd><p>Interleave the upper field from odd frames with the lower field from
|
|
even frames, generating a frame with unchanged height at half framerate.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>5</samp>’</dt>
|
|
<dd><p>Interleave the lower field from odd frames with the upper field from
|
|
even frames, generating a frame with unchanged height at half framerate.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default mode is 0.
|
|
</p>
|
|
<a name="transpose"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-transpose">24.39 transpose</a></h2>
|
|
|
|
<p>Transpose rows with columns in the input video and optionally flip it.
|
|
</p>
|
|
<p>It accepts a parameter representing an integer, which can assume the
|
|
values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
|
|
</p><table><tr><td> </td><td><pre class="example">L.R L.l
|
|
. . -> . .
|
|
l.r R.r
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>Rotate by 90 degrees clockwise, that is:
|
|
</p><table><tr><td> </td><td><pre class="example">L.R l.L
|
|
. . -> . .
|
|
l.r r.R
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>Rotate by 90 degrees counterclockwise, that is:
|
|
</p><table><tr><td> </td><td><pre class="example">L.R R.r
|
|
. . -> . .
|
|
l.r L.l
|
|
</pre></td></tr></table>
|
|
|
|
</dd>
|
|
<dt> ‘<samp>3</samp>’</dt>
|
|
<dd><p>Rotate by 90 degrees clockwise and vertically flip, that is:
|
|
</p><table><tr><td> </td><td><pre class="example">L.R r.R
|
|
. . -> . .
|
|
l.r l.L
|
|
</pre></td></tr></table>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="unsharp"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-unsharp">24.40 unsharp</a></h2>
|
|
|
|
<p>Sharpen or blur the input video.
|
|
</p>
|
|
<p>It accepts the following parameters:
|
|
<var>luma_msize_x</var>:<var>luma_msize_y</var>:<var>luma_amount</var>:<var>chroma_msize_x</var>:<var>chroma_msize_y</var>:<var>chroma_amount</var>
|
|
</p>
|
|
<p>Negative values for the amount will blur the input video, while positive
|
|
values will sharpen. All parameters are optional and default to the
|
|
equivalent of the string ’5:5:1.0:5:5:0.0’.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>luma_msize_x</samp>’</dt>
|
|
<dd><p>Set the luma matrix horizontal size. It can be an integer between 3
|
|
and 13, default value is 5.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>luma_msize_y</samp>’</dt>
|
|
<dd><p>Set the luma matrix vertical size. It can be an integer between 3
|
|
and 13, default value is 5.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>luma_amount</samp>’</dt>
|
|
<dd><p>Set the luma effect strength. It can be a float number between -2.0
|
|
and 5.0, default value is 1.0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>chroma_msize_x</samp>’</dt>
|
|
<dd><p>Set the chroma matrix horizontal size. It can be an integer between 3
|
|
and 13, default value is 5.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>chroma_msize_y</samp>’</dt>
|
|
<dd><p>Set the chroma matrix vertical size. It can be an integer between 3
|
|
and 13, default value is 5.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>chroma_amount</samp>’</dt>
|
|
<dd><p>Set the chroma effect strength. It can be a float number between -2.0
|
|
and 5.0, default value is 0.0.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<table><tr><td> </td><td><pre class="example"># Strong luma sharpen effect parameters
|
|
unsharp=7:7:2.5
|
|
|
|
# Strong blur of both luma and chroma parameters
|
|
unsharp=7:7:-2:7:7:-2
|
|
|
|
# Use the default values with <code>ffmpeg</code>
|
|
ffmpeg -i in.avi -vf "unsharp" out.mp4
|
|
</pre></td></tr></table>
|
|
|
|
<a name="vflip"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-vflip">24.41 vflip</a></h2>
|
|
|
|
<p>Flip the input video vertically.
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">ffmpeg -i in.avi -vf "vflip" out.avi
|
|
</pre></td></tr></table>
|
|
|
|
<a name="yadif"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-yadif">24.42 yadif</a></h2>
|
|
|
|
<p>Deinterlace the input video ("yadif" means "yet another deinterlacing
|
|
filter").
|
|
</p>
|
|
<p>It accepts the optional parameters: <var>mode</var>:<var>parity</var>:<var>auto</var>.
|
|
</p>
|
|
<p><var>mode</var> specifies the interlacing mode to adopt, accepts one of the
|
|
following values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>output 1 frame for each frame
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>output 1 frame for each field
|
|
</p></dd>
|
|
<dt> ‘<samp>2</samp>’</dt>
|
|
<dd><p>like 0 but skips spatial interlacing check
|
|
</p></dd>
|
|
<dt> ‘<samp>3</samp>’</dt>
|
|
<dd><p>like 1 but skips spatial interlacing check
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is 0.
|
|
</p>
|
|
<p><var>parity</var> specifies the picture field parity assumed for the input
|
|
interlaced video, accepts one of the following values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>assume top field first
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>assume bottom field first
|
|
</p></dd>
|
|
<dt> ‘<samp>-1</samp>’</dt>
|
|
<dd><p>enable automatic detection
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is -1.
|
|
If interlacing is unknown or decoder does not export this information,
|
|
top field first will be assumed.
|
|
</p>
|
|
<p><var>auto</var> specifies if deinterlacer should trust the interlaced flag
|
|
and only deinterlace frames marked as interlaced
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>0</samp>’</dt>
|
|
<dd><p>deinterlace all frames
|
|
</p></dd>
|
|
<dt> ‘<samp>1</samp>’</dt>
|
|
<dd><p>only deinterlace frames marked as interlaced
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is 0.
|
|
</p>
|
|
|
|
<a name="Video-Sources"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Video-Sources">25. Video Sources</a></h1>
|
|
|
|
<p>Below is a description of the currently available video sources.
|
|
</p>
|
|
<a name="buffer"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-buffer">25.1 buffer</a></h2>
|
|
|
|
<p>Buffer video frames, and make them available to the filter chain.
|
|
</p>
|
|
<p>This source is mainly intended for a programmatic use, in particular
|
|
through the interface defined in ‘<tt>libavfilter/vsrc_buffer.h</tt>’.
|
|
</p>
|
|
<p>It accepts the following parameters:
|
|
<var>width</var>:<var>height</var>:<var>pix_fmt_string</var>:<var>timebase_num</var>:<var>timebase_den</var>:<var>sample_aspect_ratio_num</var>:<var>sample_aspect_ratio.den</var>:<var>scale_params</var>
|
|
</p>
|
|
<p>All the parameters but <var>scale_params</var> need to be explicitly
|
|
defined.
|
|
</p>
|
|
<p>Follows the list of the accepted parameters.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>width, height</samp>’</dt>
|
|
<dd><p>Specify the width and height of the buffered video frames.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pix_fmt_string</samp>’</dt>
|
|
<dd><p>A string representing the pixel format of the buffered video frames.
|
|
It may be a number corresponding to a pixel format, or a pixel format
|
|
name.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>timebase_num, timebase_den</samp>’</dt>
|
|
<dd><p>Specify numerator and denomitor of the timebase assumed by the
|
|
timestamps of the buffered frames.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sample_aspect_ratio.num, sample_aspect_ratio.den</samp>’</dt>
|
|
<dd><p>Specify numerator and denominator of the sample aspect ratio assumed
|
|
by the video frames.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>scale_params</samp>’</dt>
|
|
<dd><p>Specify the optional parameters to be used for the scale filter which
|
|
is automatically inserted when an input change is detected in the
|
|
input size or format.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>For example:
|
|
</p><table><tr><td> </td><td><pre class="example">buffer=320:240:yuv410p:1:24:1:1
|
|
</pre></td></tr></table>
|
|
|
|
<p>will instruct the source to accept video frames with size 320x240 and
|
|
with format "yuv410p", assuming 1/24 as the timestamps timebase and
|
|
square pixels (1:1 sample aspect ratio).
|
|
Since the pixel format with name "yuv410p" corresponds to the number 6
|
|
(check the enum PixelFormat definition in ‘<tt>libavutil/pixfmt.h</tt>’),
|
|
this example corresponds to:
|
|
</p><table><tr><td> </td><td><pre class="example">buffer=320:240:6:1:24:1:1
|
|
</pre></td></tr></table>
|
|
|
|
<a name="cellauto"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-cellauto">25.2 cellauto</a></h2>
|
|
|
|
<p>Create a pattern generated by an elementary cellular automaton.
|
|
</p>
|
|
<p>The initial state of the cellular automaton can be defined through the
|
|
‘<samp>filename</samp>’, and ‘<samp>pattern</samp>’ options. If such options are
|
|
not specified an initial state is created randomly.
|
|
</p>
|
|
<p>At each new frame a new row in the video is filled with the result of
|
|
the cellular automaton next generation. The behavior when the whole
|
|
frame is filled is defined by the ‘<samp>scroll</samp>’ option.
|
|
</p>
|
|
<p>This source accepts a list of options in the form of
|
|
<var>key</var>=<var>value</var> pairs separated by ":". A description of the
|
|
accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>filename, f</samp>’</dt>
|
|
<dd><p>Read the initial cellular automaton state, i.e. the starting row, from
|
|
the specified file.
|
|
In the file, each non-whitespace character is considered an alive
|
|
cell, a newline will terminate the row, and further characters in the
|
|
file will be ignored.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>pattern, p</samp>’</dt>
|
|
<dd><p>Read the initial cellular automaton state, i.e. the starting row, from
|
|
the specified string.
|
|
</p>
|
|
<p>Each non-whitespace character in the string is considered an alive
|
|
cell, a newline will terminate the row, and further characters in the
|
|
string will be ignored.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rate, r</samp>’</dt>
|
|
<dd><p>Set the video rate, that is the number of frames generated per second.
|
|
Default is 25.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>random_fill_ratio, ratio</samp>’</dt>
|
|
<dd><p>Set the random fill ratio for the initial cellular automaton row. It
|
|
is a floating point number value ranging from 0 to 1, defaults to
|
|
1/PHI.
|
|
</p>
|
|
<p>This option is ignored when a file or a pattern is specified.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>random_seed, seed</samp>’</dt>
|
|
<dd><p>Set the seed for filling randomly the initial row, must be an integer
|
|
included between 0 and UINT32_MAX. If not specified, or if explicitly
|
|
set to -1, the filter will try to use a good random seed on a best
|
|
effort basis.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rule</samp>’</dt>
|
|
<dd><p>Set the cellular automaton rule, it is a number ranging from 0 to 255.
|
|
Default value is 110.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>size, s</samp>’</dt>
|
|
<dd><p>Set the size of the output video.
|
|
</p>
|
|
<p>If ‘<samp>filename</samp>’ or ‘<samp>pattern</samp>’ is specified, the size is set
|
|
by default to the width of the specified initial state row, and the
|
|
height is set to <var>width</var> * PHI.
|
|
</p>
|
|
<p>If ‘<samp>size</samp>’ is set, it must contain the width of the specified
|
|
pattern string, and the specified pattern will be centered in the
|
|
larger row.
|
|
</p>
|
|
<p>If a filename or a pattern string is not specified, the size value
|
|
defaults to "320x518" (used for a randomly generated initial state).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>scroll</samp>’</dt>
|
|
<dd><p>If set to 1, scroll the output upward when all the rows in the output
|
|
have been already filled. If set to 0, the new generated row will be
|
|
written over the top row just after the bottom row is filled.
|
|
Defaults to 1.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>start_full, full</samp>’</dt>
|
|
<dd><p>If set to 1, completely fill the output with generated rows before
|
|
outputting the first frame.
|
|
This is the default behavior, for disabling set the value to 0.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>stitch</samp>’</dt>
|
|
<dd><p>If set to 1, stitch the left and right row edges together.
|
|
This is the default behavior, for disabling set the value to 0.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Examples-5"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-5">25.2.1 Examples</a></h3>
|
|
|
|
<ul>
|
|
<li>
|
|
Read the initial state from ‘<tt>pattern</tt>’, and specify an output of
|
|
size 200x400.
|
|
<table><tr><td> </td><td><pre class="example">cellauto=f=pattern:s=200x400
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Generate a random initial row with a width of 200 cells, with a fill
|
|
ratio of 2/3:
|
|
<table><tr><td> </td><td><pre class="example">cellauto=ratio=2/3:s=200x200
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Create a pattern generated by rule 18 starting by a single alive cell
|
|
centered on an initial row with width 100:
|
|
<table><tr><td> </td><td><pre class="example">cellauto=p=@:s=100x400:full=0:rule=18
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Specify a more elaborated initial pattern:
|
|
<table><tr><td> </td><td><pre class="example">cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
|
|
</pre></td></tr></table>
|
|
|
|
</li></ul>
|
|
|
|
<a name="color"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-color">25.3 color</a></h2>
|
|
|
|
<p>Provide an uniformly colored input.
|
|
</p>
|
|
<p>It accepts the following parameters:
|
|
<var>color</var>:<var>frame_size</var>:<var>frame_rate</var>
|
|
</p>
|
|
<p>Follows the description of the accepted parameters.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>color</samp>’</dt>
|
|
<dd><p>Specify the color of the source. It can be the name of a color (case
|
|
insensitive match) or a 0xRRGGBB[AA] sequence, possibly followed by an
|
|
alpha specifier. The default value is "black".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>frame_size</samp>’</dt>
|
|
<dd><p>Specify the size of the sourced video, it may be a string of the form
|
|
<var>width</var>x<var>height</var>, or the name of a size abbreviation. The
|
|
default value is "320x240".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>frame_rate</samp>’</dt>
|
|
<dd><p>Specify the frame rate of the sourced video, as the number of frames
|
|
generated per second. It has to be a string in the format
|
|
<var>frame_rate_num</var>/<var>frame_rate_den</var>, an integer number, a float
|
|
number or a valid video frame rate abbreviation. The default value is
|
|
"25".
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>For example the following graph description will generate a red source
|
|
with an opacity of 0.2, with size "qcif" and a frame rate of 10
|
|
frames per second, which will be overlayed over the source connected
|
|
to the pad with identifier "in".
|
|
</p>
|
|
<table><tr><td> </td><td><pre class="example">"color=red@0.2:qcif:10 [color]; [in][color] overlay [out]"
|
|
</pre></td></tr></table>
|
|
|
|
<a name="movie"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-movie">25.4 movie</a></h2>
|
|
|
|
<p>Read a video stream from a movie container.
|
|
</p>
|
|
<p>It accepts the syntax: <var>movie_name</var>[:<var>options</var>] where
|
|
<var>movie_name</var> is the name of the resource to read (not necessarily
|
|
a file but also a device or a stream accessed through some protocol),
|
|
and <var>options</var> is an optional sequence of <var>key</var>=<var>value</var>
|
|
pairs, separated by ":".
|
|
</p>
|
|
<p>The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>format_name, f</samp>’</dt>
|
|
<dd><p>Specifies the format assumed for the movie to read, and can be either
|
|
the name of a container or an input device. If not specified the
|
|
format is guessed from <var>movie_name</var> or by probing.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>seek_point, sp</samp>’</dt>
|
|
<dd><p>Specifies the seek point in seconds, the frames will be output
|
|
starting from this seek point, the parameter is evaluated with
|
|
<code>av_strtod</code> so the numerical value may be suffixed by an IS
|
|
postfix. Default value is "0".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>stream_index, si</samp>’</dt>
|
|
<dd><p>Specifies the index of the video stream to read. If the value is -1,
|
|
the best suited video stream will be automatically selected. Default
|
|
value is "-1".
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>This filter allows to overlay a second video on top of main input of
|
|
a filtergraph as shown in this graph:
|
|
</p><table><tr><td> </td><td><pre class="example">input -----------> deltapts0 --> overlay --> output
|
|
^
|
|
|
|
|
movie --> scale--> deltapts1 -------+
|
|
</pre></td></tr></table>
|
|
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># skip 3.2 seconds from the start of the avi file in.avi, and overlay it
|
|
# on top of the input labelled as "in".
|
|
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [movie];
|
|
[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
|
|
|
|
# read from a video4linux2 device, and overlay it on top of the input
|
|
# labelled as "in"
|
|
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [movie];
|
|
[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
|
|
|
|
</pre></td></tr></table>
|
|
|
|
<a name="mptestsrc"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-mptestsrc">25.5 mptestsrc</a></h2>
|
|
|
|
<p>Generate various test patterns, as generated by the MPlayer test filter.
|
|
</p>
|
|
<p>The size of the generated video is fixed, and is 256x256.
|
|
This source is useful in particular for testing encoding features.
|
|
</p>
|
|
<p>This source accepts an optional sequence of <var>key</var>=<var>value</var> pairs,
|
|
separated by ":". The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>rate, r</samp>’</dt>
|
|
<dd><p>Specify the frame rate of the sourced video, as the number of frames
|
|
generated per second. It has to be a string in the format
|
|
<var>frame_rate_num</var>/<var>frame_rate_den</var>, an integer number, a float
|
|
number or a valid video frame rate abbreviation. The default value is
|
|
"25".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>duration, d</samp>’</dt>
|
|
<dd><p>Set the video duration of the sourced video. The accepted syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">[-]HH[:MM[:SS[.m...]]]
|
|
[-]S+[.m...]
|
|
</pre></td></tr></table>
|
|
<p>See also the function <code>av_parse_time()</code>.
|
|
</p>
|
|
<p>If not specified, or the expressed duration is negative, the video is
|
|
supposed to be generated forever.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>test, t</samp>’</dt>
|
|
<dd>
|
|
<p>Set the number or the name of the test to perform. Supported tests are:
|
|
</p><dl compact="compact">
|
|
<dt> ‘<samp>dc_luma</samp>’</dt>
|
|
<dt> ‘<samp>dc_chroma</samp>’</dt>
|
|
<dt> ‘<samp>freq_luma</samp>’</dt>
|
|
<dt> ‘<samp>freq_chroma</samp>’</dt>
|
|
<dt> ‘<samp>amp_luma</samp>’</dt>
|
|
<dt> ‘<samp>amp_chroma</samp>’</dt>
|
|
<dt> ‘<samp>cbp</samp>’</dt>
|
|
<dt> ‘<samp>mv</samp>’</dt>
|
|
<dt> ‘<samp>ring1</samp>’</dt>
|
|
<dt> ‘<samp>ring2</samp>’</dt>
|
|
<dt> ‘<samp>all</samp>’</dt>
|
|
</dl>
|
|
|
|
<p>Default value is "all", which will cycle through the list of all tests.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>For example the following:
|
|
</p><table><tr><td> </td><td><pre class="example">testsrc=t=dc_luma
|
|
</pre></td></tr></table>
|
|
|
|
<p>will generate a "dc_luma" test pattern.
|
|
</p>
|
|
<a name="frei0r_005fsrc"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-frei0r_005fsrc">25.6 frei0r_src</a></h2>
|
|
|
|
<p>Provide a frei0r source.
|
|
</p>
|
|
<p>To enable compilation of this filter you need to install the frei0r
|
|
header and configure FFmpeg with <code>--enable-frei0r</code>.
|
|
</p>
|
|
<p>The source supports the syntax:
|
|
</p><table><tr><td> </td><td><pre class="example"><var>size</var>:<var>rate</var>:<var>src_name</var>[{=|:}<var>param1</var>:<var>param2</var>:...:<var>paramN</var>]
|
|
</pre></td></tr></table>
|
|
|
|
<p><var>size</var> is the size of the video to generate, may be a string of the
|
|
form <var>width</var>x<var>height</var> or a frame size abbreviation.
|
|
<var>rate</var> is the rate of the video to generate, may be a string of
|
|
the form <var>num</var>/<var>den</var> or a frame rate abbreviation.
|
|
<var>src_name</var> is the name to the frei0r source to load. For more
|
|
information regarding frei0r and how to set the parameters read the
|
|
section <a href="#frei0r">frei0r</a> in the description of the video filters.
|
|
</p>
|
|
<p>Some examples follow:
|
|
</p><table><tr><td> </td><td><pre class="example"># generate a frei0r partik0l source with size 200x200 and frame rate 10
|
|
# which is overlayed on the overlay filter main input
|
|
frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
|
|
</pre></td></tr></table>
|
|
|
|
<a name="life"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-life">25.7 life</a></h2>
|
|
|
|
<p>Generate a life pattern.
|
|
</p>
|
|
<p>This source is based on a generalization of John Conway’s life game.
|
|
</p>
|
|
<p>The sourced input represents a life grid, each pixel represents a cell
|
|
which can be in one of two possible states, alive or dead. Every cell
|
|
interacts with its eight neighbours, which are the cells that are
|
|
horizontally, vertically, or diagonally adjacent.
|
|
</p>
|
|
<p>At each interaction the grid evolves according to the adopted rule,
|
|
which specifies the number of neighbor alive cells which will make a
|
|
cell stay alive or born. The ‘<samp>rule</samp>’ option allows to specify
|
|
the rule to adopt.
|
|
</p>
|
|
<p>This source accepts a list of options in the form of
|
|
<var>key</var>=<var>value</var> pairs separated by ":". A description of the
|
|
accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>filename, f</samp>’</dt>
|
|
<dd><p>Set the file from which to read the initial grid state. In the file,
|
|
each non-whitespace character is considered an alive cell, and newline
|
|
is used to delimit the end of each row.
|
|
</p>
|
|
<p>If this option is not specified, the initial grid is generated
|
|
randomly.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rate, r</samp>’</dt>
|
|
<dd><p>Set the video rate, that is the number of frames generated per second.
|
|
Default is 25.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>random_fill_ratio, ratio</samp>’</dt>
|
|
<dd><p>Set the random fill ratio for the initial random grid. It is a
|
|
floating point number value ranging from 0 to 1, defaults to 1/PHI.
|
|
It is ignored when a file is specified.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>random_seed, seed</samp>’</dt>
|
|
<dd><p>Set the seed for filling the initial random grid, must be an integer
|
|
included between 0 and UINT32_MAX. If not specified, or if explicitly
|
|
set to -1, the filter will try to use a good random seed on a best
|
|
effort basis.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rule</samp>’</dt>
|
|
<dd><p>Set the life rule.
|
|
</p>
|
|
<p>A rule can be specified with a code of the kind "S<var>NS</var>/B<var>NB</var>",
|
|
where <var>NS</var> and <var>NB</var> are sequences of numbers in the range 0-8,
|
|
<var>NS</var> specifies the number of alive neighbor cells which make a
|
|
live cell stay alive, and <var>NB</var> the number of alive neighbor cells
|
|
which make a dead cell to become alive (i.e. to "born").
|
|
"s" and "b" can be used in place of "S" and "B", respectively.
|
|
</p>
|
|
<p>Alternatively a rule can be specified by an 18-bits integer. The 9
|
|
high order bits are used to encode the next cell state if it is alive
|
|
for each number of neighbor alive cells, the low order bits specify
|
|
the rule for "borning" new cells. Higher order bits encode for an
|
|
higher number of neighbor cells.
|
|
For example the number 6153 = <code>(12<<9)+9</code> specifies a stay alive
|
|
rule of 12 and a born rule of 9, which corresponds to "S23/B03".
|
|
</p>
|
|
<p>Default value is "S23/B3", which is the original Conway’s game of life
|
|
rule, and will keep a cell alive if it has 2 or 3 neighbor alive
|
|
cells, and will born a new cell if there are three alive cells around
|
|
a dead cell.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>size, s</samp>’</dt>
|
|
<dd><p>Set the size of the output video.
|
|
</p>
|
|
<p>If ‘<samp>filename</samp>’ is specified, the size is set by default to the
|
|
same size of the input file. If ‘<samp>size</samp>’ is set, it must contain
|
|
the size specified in the input file, and the initial grid defined in
|
|
that file is centered in the larger resulting area.
|
|
</p>
|
|
<p>If a filename is not specified, the size value defaults to "320x240"
|
|
(used for a randomly generated initial grid).
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>stitch</samp>’</dt>
|
|
<dd><p>If set to 1, stitch the left and right grid edges together, and the
|
|
top and bottom edges also. Defaults to 1.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>mold</samp>’</dt>
|
|
<dd><p>Set cell mold speed. If set, a dead cell will go from ‘<samp>death_color</samp>’ to
|
|
‘<samp>mold_color</samp>’ with a step of ‘<samp>mold</samp>’. ‘<samp>mold</samp>’ can have a
|
|
value from 0 to 255.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>life_color</samp>’</dt>
|
|
<dd><p>Set the color of living (or new born) cells.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>death_color</samp>’</dt>
|
|
<dd><p>Set the color of dead cells. If ‘<samp>mold</samp>’ is set, this is the first color
|
|
used to represent a dead cell.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>mold_color</samp>’</dt>
|
|
<dd><p>Set mold color, for definitely dead and moldy cells.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Examples-8"></a>
|
|
<h3 class="subsection"><a href="ffmpeg.html#toc-Examples-8">25.7.1 Examples</a></h3>
|
|
|
|
<ul>
|
|
<li>
|
|
Read a grid from ‘<tt>pattern</tt>’, and center it on a grid of size
|
|
300x300 pixels:
|
|
<table><tr><td> </td><td><pre class="example">life=f=pattern:s=300x300
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Generate a random grid of size 200x200, with a fill ratio of 2/3:
|
|
<table><tr><td> </td><td><pre class="example">life=ratio=2/3:s=200x200
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Specify a custom rule for evolving a randomly generated grid:
|
|
<table><tr><td> </td><td><pre class="example">life=rule=S14/B34
|
|
</pre></td></tr></table>
|
|
|
|
</li><li>
|
|
Full example with slow death effect (mold) using <code>ffplay</code>:
|
|
<table><tr><td> </td><td><pre class="example">ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
|
|
</pre></td></tr></table>
|
|
</li></ul>
|
|
|
|
<a name="nullsrc_002c-rgbtestsrc_002c-testsrc"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-nullsrc_002c-rgbtestsrc_002c-testsrc">25.8 nullsrc, rgbtestsrc, testsrc</a></h2>
|
|
|
|
<p>The <code>nullsrc</code> source returns unprocessed video frames. It is
|
|
mainly useful to be employed in analysis / debugging tools, or as the
|
|
source for filters which ignore the input data.
|
|
</p>
|
|
<p>The <code>rgbtestsrc</code> source generates an RGB test pattern useful for
|
|
detecting RGB vs BGR issues. You should see a red, green and blue
|
|
stripe from top to bottom.
|
|
</p>
|
|
<p>The <code>testsrc</code> source generates a test video pattern, showing a
|
|
color pattern, a scrolling gradient and a timestamp. This is mainly
|
|
intended for testing purposes.
|
|
</p>
|
|
<p>These sources accept an optional sequence of <var>key</var>=<var>value</var> pairs,
|
|
separated by ":". The description of the accepted options follows.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt> ‘<samp>size, s</samp>’</dt>
|
|
<dd><p>Specify the size of the sourced video, it may be a string of the form
|
|
<var>width</var>x<var>height</var>, or the name of a size abbreviation. The
|
|
default value is "320x240".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>rate, r</samp>’</dt>
|
|
<dd><p>Specify the frame rate of the sourced video, as the number of frames
|
|
generated per second. It has to be a string in the format
|
|
<var>frame_rate_num</var>/<var>frame_rate_den</var>, an integer number, a float
|
|
number or a valid video frame rate abbreviation. The default value is
|
|
"25".
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>sar</samp>’</dt>
|
|
<dd><p>Set the sample aspect ratio of the sourced video.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>duration, d</samp>’</dt>
|
|
<dd><p>Set the video duration of the sourced video. The accepted syntax is:
|
|
</p><table><tr><td> </td><td><pre class="example">[-]HH[:MM[:SS[.m...]]]
|
|
[-]S+[.m...]
|
|
</pre></td></tr></table>
|
|
<p>See also the function <code>av_parse_time()</code>.
|
|
</p>
|
|
<p>If not specified, or the expressed duration is negative, the video is
|
|
supposed to be generated forever.
|
|
</p>
|
|
</dd>
|
|
<dt> ‘<samp>decimals, n</samp>’</dt>
|
|
<dd><p>Set the number of decimals to show in the timestamp, only used in the
|
|
<code>testsrc</code> source.
|
|
</p>
|
|
<p>The displayed timestamp value will correspond to the original
|
|
timestamp value multiplied by the power of 10 of the specified
|
|
value. Default value is 0.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>For example the following:
|
|
</p><table><tr><td> </td><td><pre class="example">testsrc=duration=5.3:size=qcif:rate=10
|
|
</pre></td></tr></table>
|
|
|
|
<p>will generate a video with a duration of 5.3 seconds, with size
|
|
176x144 and a frame rate of 10 frames per second.
|
|
</p>
|
|
<p>If the input content is to be ignored, <code>nullsrc</code> can be used. The
|
|
following command generates noise in the luminance plane by employing
|
|
the <code>mp=geq</code> filter:
|
|
</p><table><tr><td> </td><td><pre class="example">nullsrc=s=256x256, mp=geq=random(1)*255:128:128
|
|
</pre></td></tr></table>
|
|
|
|
|
|
<a name="Video-Sinks"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Video-Sinks">26. Video Sinks</a></h1>
|
|
|
|
<p>Below is a description of the currently available video sinks.
|
|
</p>
|
|
<a name="buffersink"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-buffersink">26.1 buffersink</a></h2>
|
|
|
|
<p>Buffer video frames, and make them available to the end of the filter
|
|
graph.
|
|
</p>
|
|
<p>This sink is mainly intended for a programmatic use, in particular
|
|
through the interface defined in ‘<tt>libavfilter/buffersink.h</tt>’.
|
|
</p>
|
|
<p>It does not require a string parameter in input, but you need to
|
|
specify a pointer to a list of supported pixel formats terminated by
|
|
-1 in the opaque parameter provided to <code>avfilter_init_filter</code>
|
|
when initializing this sink.
|
|
</p>
|
|
<a name="nullsink"></a>
|
|
<h2 class="section"><a href="ffmpeg.html#toc-nullsink">26.2 nullsink</a></h2>
|
|
|
|
<p>Null video sink, do absolutely nothing with the input video. It is
|
|
mainly useful as a template and to be employed in analysis / debugging
|
|
tools.
|
|
</p>
|
|
|
|
<a name="Metadata"></a>
|
|
<h1 class="chapter"><a href="ffmpeg.html#toc-Metadata">27. Metadata</a></h1>
|
|
|
|
<p>FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
|
|
INI-like text file and then load it back using the metadata muxer/demuxer.
|
|
</p>
|
|
<p>The file format is as follows:
|
|
</p><ol>
|
|
<li>
|
|
A file consists of a header and a number of metadata tags divided into sections,
|
|
each on its own line.
|
|
|
|
</li><li>
|
|
The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
|
|
|
|
</li><li>
|
|
Metadata tags are of the form ’key=value’
|
|
|
|
</li><li>
|
|
Immediately after header follows global metadata
|
|
|
|
</li><li>
|
|
After global metadata there may be sections with per-stream/per-chapter
|
|
metadata.
|
|
|
|
</li><li>
|
|
A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
|
|
brackets (’[’, ’]’) and ends with next section or end of file.
|
|
|
|
</li><li>
|
|
At the beginning of a chapter section there may be an optional timebase to be
|
|
used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
|
|
den are integers. If the timebase is missing then start/end times are assumed to
|
|
be in milliseconds.
|
|
Next a chapter section must contain chapter start and end times in form
|
|
’START=num’, ’END=num’, where num is a positive integer.
|
|
|
|
</li><li>
|
|
Empty lines and lines starting with ’;’ or ’#’ are ignored.
|
|
|
|
</li><li>
|
|
Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
|
|
newline) must be escaped with a backslash ’\’.
|
|
|
|
</li><li>
|
|
Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
|
|
the tag (in the example above key is ’foo ’, value is ’ bar’).
|
|
</li></ol>
|
|
|
|
<p>A ffmetadata file might look like this:
|
|
</p><table><tr><td> </td><td><pre class="example">;FFMETADATA1
|
|
title=bike\\shed
|
|
;this is a comment
|
|
artist=FFmpeg troll team
|
|
|
|
[CHAPTER]
|
|
TIMEBASE=1/1000
|
|
START=0
|
|
#chapter ends at 0:01:00
|
|
END=60000
|
|
title=chapter \#1
|
|
[STREAM]
|
|
title=multi\
|
|
line
|
|
</pre></td></tr></table>
|
|
|
|
|
|
<div id="footer">
|
|
<p>
|
|
<font size="-1">
|
|
This document was generated by <em>Kyle</em> on <em>January 27, 2012</em> using <a href="http://www.nongnu.org/texi2html/"><em>texi2html 1.82</em></a>.
|
|
</font>
|
|
<br>
|
|
</div></div>
|
|
</p>
|
|
</body>
|
|
</html>
|
|
</div>
|