Allow for the va library to be used with ffmpeg.

This needs verifying.

CMake/DefineOptions.cmake

@@ -26,6 +26,7 @@ else()
     option(WITH_FFMPEG "Build with FFMPEG." ON)
     # Builder beware: later versions of ffmpeg may break!
     option(WITH_SYSTEM_FFMPEG "Build with the system's FFMPEG." OFF)
+    option(WITH_LIBVA "Build with libVa support for Video Acceleration." OFF)
     option(WITH_TTY "Build with Linux TTY Input Support." OFF)
     option(WITH_PROFILING "Build with Profiling Support." OFF)
     option(WITH_GLES2 "Build with OpenGL ES 2.0 Support." ON)

CMake/Modules/FindVa.cmake

@@ -0,0 +1,17 @@
+# Find the Video Acceleration library.
+
+# The following will be set:
+
+# VA_INCLUDE_DIR
+# VA_LIBRARY
+# VA_FOUND
+
+find_path(VA_INCLUDE_DIR NAMES va/va.h)
+
+set(VA_NAMES "${VA_NAMES}" "va" "libva")
+find_library(VA_LIBRARY NAMES ${VA_NAMES})
+
+include(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(VA DEFAULT_MSG VA_LIBRARY VA_INCLUDE_DIR)
+
+mark_as_advanced(VA_LIBRARY VA_INCLUDE_DIR)

CMakeLists.txt

@@ -256,6 +256,10 @@ elseif(LINUX)
   endif()
 
   if(WITH_FFMPEG)
+    if(WITH_LIBVA)
+      find_package(VA)
+    endif()
+
     if (WITH_SYSTEM_FFMPEG)
       find_package("FFMPEG")
       if(NOT FFMPEG_FOUND)
@@ -293,6 +297,12 @@ elseif(LINUX)
         )
       endif()
 
+      if(WITH_LIBVA AND VA_FOUND)
+        list(APPEND FFMPEG_CONFIGURE
+          "--extra-ldflags=-lva"
+        )
+      endif()
+
       if (IS_DIRECTORY "${SM_FFMPEG_SRC_DIR}")
         externalproject_add("ffmpeg"
           SOURCE_DIR "${SM_FFMPEG_SRC_DIR}"