From Tanguy Fautre,

Clean up of the FFmpeg plugin's class API/AudioStream API. 
Implementation of isImageTransparent().
Implementation of Image:g/setPixelAspectRatio()

src/osgPlugins/ffmpeg/FFmpegAudioStream.cpp

@@ -51,12 +51,6 @@ double FFmpegAudioStream::duration() const
 }
 
 
-bool FFmpegAudioStream::audioStream() const 
-{ 
-    return m_decoder->audio_decoder().validContext(); 
-}
-
-
 
 int FFmpegAudioStream::audioFrequency() const 
 {