Don't double correct for discarded codec delay frames.

media/filters/audio_file_reader.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_FILTERS_AUDIO_FILE_READER_H_
 #define MEDIA_FILTERS_AUDIO_FILE_READER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "media/base/media_export.h"
 
 struct AVCodecContext;
+struct AVPacket;
 
 namespace base { class TimeDelta; }
 
 namespace media {
 
 class AudioBus;
 class FFmpegGlue;
 class FFmpegURLProtocol;
 
 class MEDIA_EXPORT AudioFileReader {
@@ skipping 24 matching lines @@
   int sample_rate() const { return sample_rate_; }
 
   // Please note that GetDuration() and GetNumberOfFrames() attempt to be
   // accurate, but are only estimates.  For some encoded formats, the actual
   // duration of the file can only be determined once all the file data has been
   // read. The Read() method returns the actual number of sample-frames it has
   // read.
   base::TimeDelta GetDuration() const;
   int GetNumberOfFrames() const;
 
+  // Helper methods which allows AudioFileReader to double as a test utility for
+  // demuxing audio files.  Returns true if a packet could be demuxed from the
+  // first audio stream in the file, |output_packet| will contain the demuxed
+  // packet then.
+  bool ReadPacketForTesting(AVPacket* output_packet);
+
+  const AVCodecContext* codec_context_for_testing() const {
+    return codec_context_;
+  }
+
  private:
+  bool ReadPacket(AVPacket* output_packet);
+
   scoped_ptr<FFmpegGlue> glue_;
   AVCodecContext* codec_context_;
   int stream_index_;
   FFmpegURLProtocol* protocol_;
   int channels_;
   int sample_rate_;
 
   // AVSampleFormat initially requested; not Chrome's SampleFormat.
   int av_sample_format_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioFileReader);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_AUDIO_FILE_READER_H_