Glenn Maynard
1bd5513698
This allows us to change the volume of sounds in filters ("volume",
"fade" properties) without quantizing the audio prematurely. Previously,
we had a hack to apply volume changes as a mixing-time step. This
can be done at any point in the filter chain now.
This also means we only need to worry about clipping at the very
last mixing step, instead of at every place we change sound.
Dithering for 16-bit audio and more intelligent gain control
is possible, as we have full-resolution, unclipped sound at the
mixing phase.
We support high resolution source sounds; both Vorbis and MAD
supply more than 16 bits.
Several filters, such as resampling, are easier to implement as
floats; these no longer need to convert back and forth.
Negatives:
- More memory use. The main case of this is in RageSoundReader_Preload,
which will be fixed: we can preload in 16-bit without losing most of the
above.
- Some extra overhead for accessing more memory.
70 lines
2.5 KiB
C++
70 lines
2.5 KiB
C++
/* RageSoundReader_Resample_Good - fast audio resampling. */
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#ifndef RAGE_SOUND_READER_RESAMPLE_GOOD_H
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#define RAGE_SOUND_READER_RESAMPLE_GOOD_H
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#include "RageSoundReader_Filter.h"
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class RageSoundResampler_Polyphase;
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/* This class changes the sampling rate of a sound. */
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class RageSoundReader_Resample_Good: public RageSoundReader_Filter
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{
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public:
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/* We own source. */
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RageSoundReader_Resample_Good( RageSoundReader *pSource, int iSampleRate );
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RageSoundReader_Resample_Good( const RageSoundReader_Resample_Good &cpy );
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int SetPosition( int iFrame );
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int Read( float *pBuf, int iFrames );
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virtual ~RageSoundReader_Resample_Good();
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RageSoundReader_Resample_Good *Copy() const;
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bool SetProperty( const RString &sProperty, float fValue );
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int GetNextSourceFrame() const;
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float GetStreamToSourceRatio() const;
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/* Change the rate of a sound without changing the sample rate. */
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void SetRate( float fRatio );
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/* SetRate() will be rounded. Get the exact rate. */
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float GetRate() const;
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int GetSampleRate() const { return m_iSampleRate; }
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private:
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void Reset();
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void ReopenResampler();
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void GetFactors( int &iDownFactor, int &iUpFactor ) const;
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vector<RageSoundResampler_Polyphase *> m_apResamplers; /* one per channel */
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int m_iSampleRate;
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float m_fRate;
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};
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#endif
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/*
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* (c) 2006 Glenn Maynard
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* All rights reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, and/or sell copies of the Software, and to permit persons to
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* whom the Software is furnished to do so, provided that the above
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* copyright notice(s) and this permission notice appear in all copies of
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* the Software and that both the above copyright notice(s) and this
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* permission notice appear in supporting documentation.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
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* THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
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* INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
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* OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
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* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
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* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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