media/filters/ffmpeg_audio_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_AUDIO_DECODER_H_
   6 #define MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
   7
   8 #include <list>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/time/time.h"
  13 #include "media/base/audio_decoder.h"
  14 #include "media/base/demuxer_stream.h"
  15 #include "media/base/sample_format.h"
  16
  17 struct AVCodecContext;
  18 struct AVFrame;
  19
  20 namespace base {
  21 class MessageLoopProxy;
  22 }
  23
  24 namespace media {
  25
  26 class AudioTimestampHelper;
  27 class DecoderBuffer;
  28 struct QueuedAudioBuffer;
  29
  30 class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
  31  public:
  32   explicit FFmpegAudioDecoder(
  33       const scoped_refptr<base::MessageLoopProxy>& message_loop);
  34   virtual ~FFmpegAudioDecoder();
  35
  36   // AudioDecoder implementation.
  37   virtual void Initialize(DemuxerStream* stream,
  38                           const PipelineStatusCB& status_cb,
  39                           const StatisticsCB& statistics_cb) OVERRIDE;
  40   virtual void Read(const ReadCB& read_cb) OVERRIDE;
  41   virtual int bits_per_channel() OVERRIDE;
  42   virtual ChannelLayout channel_layout() OVERRIDE;
  43   virtual int samples_per_second() OVERRIDE;
  44   virtual void Reset(const base::Closure& closure) OVERRIDE;
  45
  46  private:
  47   // Reads from the demuxer stream with corresponding callback method.
  48   void ReadFromDemuxerStream();
  49   void BufferReady(DemuxerStream::Status status,
  50                    const scoped_refptr<DecoderBuffer>& input);
  51
  52   bool ConfigureDecoder();
  53   void ReleaseFFmpegResources();
  54   void ResetTimestampState();
  55   void RunDecodeLoop(const scoped_refptr<DecoderBuffer>& input,
  56                      bool skip_eos_append);
  57
  58   scoped_refptr<base::MessageLoopProxy> message_loop_;
  59   base::WeakPtrFactory<FFmpegAudioDecoder> weak_factory_;
  60   base::WeakPtr<FFmpegAudioDecoder> weak_this_;
  61
  62   DemuxerStream* demuxer_stream_;
  63   StatisticsCB statistics_cb_;
  64   AVCodecContext* codec_context_;
  65
  66   // Decoded audio format.
  67   int bits_per_channel_;
  68   ChannelLayout channel_layout_;
  69   int channels_;
  70   int samples_per_second_;
  71
  72   // AVSampleFormat initially requested; not Chrome's SampleFormat.
  73   int av_sample_format_;
  74   SampleFormat sample_format_;
  75
  76   // Used for computing output timestamps.
  77   scoped_ptr<AudioTimestampHelper> output_timestamp_helper_;
  78   base::TimeDelta last_input_timestamp_;
  79
  80   // Number of frames to drop before generating output buffers.
  81   int output_frames_to_drop_;
  82
  83   // Holds decoded audio.
  84   AVFrame* av_frame_;
  85
  86   ReadCB read_cb_;
  87
  88   // Since multiple frames may be decoded from the same packet we need to queue
  89   // them up and hand them out as we receive Read() calls.
  90   std::list<QueuedAudioBuffer> queued_audio_;
  91
  92   DISALLOW_IMPLICIT_CONSTRUCTORS(FFmpegAudioDecoder);
  93 };
  94
  95 }  // namespace media
  96
  97 #endif  // MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_