Reorganize bitstream converter classes.

media/filters/bitstream_converter.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.
 
 // Interface and some concrete classes for applying various transforms
 // to AVPackets.  FFmpegBitstreamConverter, in particular, can be used
 // to apply FFmpeg bitstream filters to the incoming AVPacket to transcode
 // the packet format.
 
 #ifndef MEDIA_FILTERS_BITSTREAM_CONVERTER_H_
@@ skipping 25 matching lines @@
   // Attemps to convert the AVPacket from one format to another, based on the
   // specific type of BitstreamConverter that was instantiated. Output will be
   // stored into the |packet|, but user should be aware that conversion can free
   // and reallocate the input buffer, if it needs to do so to fit it in.
   virtual bool ConvertPacket(AVPacket* packet) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BitstreamConverter);
 };
 
-class IdentityBitstreamConverter : public BitstreamConverter {
- public:
-  IdentityBitstreamConverter() {}
-  virtual ~IdentityBitstreamConverter() {}
-
-  virtual bool Initialize() OVERRIDE;
-  virtual bool ConvertPacket(AVPacket* packet) OVERRIDE;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(IdentityBitstreamConverter);
-};
-
 class MEDIA_EXPORT FFmpegBitstreamConverter : public BitstreamConverter {

[Ami GONE FROM CHROMIUM, 2012/07/11 17:25:47]

Any reason not to collapse this into the base now that it's the only impl?

  public:
   // Creates FFmpegBitstreamConverter based on the FFmpeg bistream filter
   // corresponding to |filter_name|.
   //
   // The |stream_context| will be used during conversion and should be the
   // AVCodecContext for the stream sourcing these packets. A reference to
   // |stream_context| is retained, so it must outlive this class.
   FFmpegBitstreamConverter(const std::string& filter_name,
                            AVCodecContext* stream_context);
   virtual ~FFmpegBitstreamConverter();
 
   virtual bool Initialize() OVERRIDE;
   virtual bool ConvertPacket(AVPacket* packet) OVERRIDE;
 
  private:
   std::string filter_name_;
   AVBitStreamFilterContext* stream_filter_;
   AVCodecContext* stream_context_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegBitstreamConverter);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_BITSTREAM_CONVERTER_H_