Support start trimming post-decoding. Use it with FFmpegDemuxer.

media/base/audio_buffer.h

Index: media/base/audio_buffer.h
diff --git a/media/base/audio_buffer.h b/media/base/audio_buffer.h
index 5d7ab7f5c6700cd05413a691e07408d43177bc53..19330ee649e7b02e8cca7b1099f2ccc05e8a97fb 100644
--- a/media/base/audio_buffer.h
+++ b/media/base/audio_buffer.h
@@ -87,6 +87,11 @@ class MEDIA_EXPORT AudioBuffer
   // Duration is adjusted to reflect the fewer frames.
   void TrimEnd(int frames_to_trim);
 
+  // Trim an AudioBuffer by removing |end - start| frames starting at |start|
+  // and ending at |end|; i.e. exclusive.  Even if start is zero, timestamp() is

[wolenetz, 2014/04/29 01:18:30]

nit: only end is exclusive, right? Perhaps rephrase to something like: remove
frames [|start|, |end|) ?

[DaleCurtis, 2014/04/30 22:04:04]

Done.

+  // not adjusted, only duration().
+  void TrimRange(int start, int end);
+
   // Return the number of channels.
   int channel_count() const { return channel_count_; }