media/filters/ffmpeg_video_decoder.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_FILTERS_FFMPEG_VIDEO_DECODER_H_
   6 #define MEDIA_FILTERS_FFMPEG_VIDEO_DECODER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "media/base/demuxer_stream.h"
  11 #include "media/base/video_decoder.h"
  12
  13 struct AVCodecContext;
  14 struct AVFrame;
  15
  16 namespace base {
  17 class MessageLoopProxy;
  18 }
  19
  20 namespace media {
  21
  22 class DecoderBuffer;
  23
  24 class MEDIA_EXPORT FFmpegVideoDecoder : public VideoDecoder {
  25  public:
  26   explicit FFmpegVideoDecoder(
  27       const scoped_refptr<base::MessageLoopProxy>& message_loop);
  28
  29   // VideoDecoder implementation.
  30   virtual void Initialize(const scoped_refptr<DemuxerStream>& stream,
  31                           const PipelineStatusCB& status_cb,
  32                           const StatisticsCB& statistics_cb) OVERRIDE;
  33   virtual void Read(const ReadCB& read_cb) OVERRIDE;
  34   virtual void Reset(const base::Closure& closure) OVERRIDE;
  35   virtual void Stop(const base::Closure& closure) OVERRIDE;
  36
  37   // Callback called from within FFmpeg to allocate a buffer based on
  38   // the dimensions of |codec_context|. See AVCodecContext.get_buffer
  39   // documentation inside FFmpeg.
  40   int GetVideoBuffer(AVCodecContext *codec_context, AVFrame* frame);
  41
  42  protected:
  43   virtual ~FFmpegVideoDecoder();
  44
  45  private:
  46   enum DecoderState {
  47     kUninitialized,
  48     kNormal,
  49     kFlushCodec,
  50     kDecodeFinished
  51   };
  52
  53   // Reads from the demuxer stream and corresponding read callback.
  54   void ReadFromDemuxerStream();
  55   void BufferReady(DemuxerStream::Status status,
  56                    const scoped_refptr<DecoderBuffer>& buffer);
  57
  58   // Handles decoding an unencrypted encoded buffer.
  59   void DecodeBuffer(const scoped_refptr<DecoderBuffer>& buffer);
  60   bool Decode(const scoped_refptr<DecoderBuffer>& buffer,
  61               scoped_refptr<VideoFrame>* video_frame);
  62
  63   // Handles (re-)initializing the decoder with a (new) config.
  64   // Returns true if initialization was successful.
  65   bool ConfigureDecoder();
  66
  67   // Releases resources associated with |codec_context_| and |av_frame_|
  68   // and resets them to NULL.
  69   void ReleaseFFmpegResources();
  70
  71   // Reset decoder and call |reset_cb_|.
  72   void DoReset();
  73
  74   scoped_refptr<base::MessageLoopProxy> message_loop_;
  75
  76   DecoderState state_;
  77
  78   StatisticsCB statistics_cb_;
  79
  80   ReadCB read_cb_;
  81   base::Closure reset_cb_;
  82
  83   // FFmpeg structures owned by this object.
  84   AVCodecContext* codec_context_;
  85   AVFrame* av_frame_;
  86
  87   // Pointer to the demuxer stream that will feed us compressed buffers.
  88   scoped_refptr<DemuxerStream> demuxer_stream_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(FFmpegVideoDecoder);
  91 };
  92
  93 }  // namespace media
  94
  95 #endif  // MEDIA_FILTERS_FFMPEG_VIDEO_DECODER_H_