media/cdm/ppapi/external_clear_key/ffmpeg_cdm_audio_decoder.h

   1 // Copyright 2013 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_CDM_PPAPI_EXTERNAL_CLEAR_KEY_FFMPEG_CDM_AUDIO_DECODER_H_
   6 #define MEDIA_CDM_PPAPI_EXTERNAL_CLEAR_KEY_FFMPEG_CDM_AUDIO_DECODER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/time/time.h"
  14 #include "media/cdm/ppapi/external_clear_key/clear_key_cdm_common.h"
  15 #include "media/ffmpeg/ffmpeg_deleters.h"
  16
  17 struct AVCodecContext;
  18 struct AVFrame;
  19
  20 namespace media {
  21 class AudioBus;
  22 class AudioTimestampHelper;
  23 }
  24
  25 namespace media {
  26 // TODO(xhwang): This class is partially cloned from FFmpegAudioDecoder. When
  27 // FFmpegAudioDecoder is updated, it's a pain to keep this class in sync with
  28 // FFmpegAudioDecoder. We need a long term sustainable solution for this. See
  29 // http://crbug.com/169203
  30 class FFmpegCdmAudioDecoder {
  31  public:
  32   explicit FFmpegCdmAudioDecoder(ClearKeyCdmHost* host);
  33   ~FFmpegCdmAudioDecoder();
  34   bool Initialize(const cdm::AudioDecoderConfig& config);
  35   void Deinitialize();
  36   void Reset();
  37
  38   // Returns true when |config| is a valid audio decoder configuration.
  39   static bool IsValidConfig(const cdm::AudioDecoderConfig& config);
  40
  41   // Decodes |compressed_buffer|. Returns |cdm::kSuccess| after storing
  42   // output in |decoded_frames| when output is available. Returns
  43   // |cdm::kNeedMoreData| when |compressed_frame| does not produce output.
  44   // Returns |cdm::kDecodeError| when decoding fails.
  45   //
  46   // A null |compressed_buffer| will attempt to flush the decoder of any
  47   // remaining frames. |compressed_buffer_size| and |timestamp| are ignored.
  48   cdm::Status DecodeBuffer(const uint8_t* compressed_buffer,
  49                            int32_t compressed_buffer_size,
  50                            int64_t timestamp,
  51                            cdm::AudioFrames* decoded_frames);
  52
  53  private:
  54   void ResetTimestampState();
  55   void ReleaseFFmpegResources();
  56
  57   base::TimeDelta GetNextOutputTimestamp() const;
  58
  59   void SerializeInt64(int64_t value);
  60
  61   bool is_initialized_;
  62
  63   ClearKeyCdmHost* const host_;
  64
  65   // FFmpeg structures owned by this object.
  66   scoped_ptr<AVCodecContext, ScopedPtrAVFreeContext> codec_context_;
  67   scoped_ptr<AVFrame, ScopedPtrAVFreeFrame> av_frame_;
  68
  69   // Audio format.
  70   int samples_per_second_;
  71   int channels_;
  72
  73   // AVSampleFormat initially requested; not Chrome's SampleFormat.
  74   int av_sample_format_;
  75
  76   // Used for computing output timestamps.
  77   scoped_ptr<AudioTimestampHelper> output_timestamp_helper_;
  78   int bytes_per_frame_;
  79   base::TimeDelta last_input_timestamp_;
  80
  81   // Number of output sample bytes to drop before generating output buffers.
  82   // This is required for handling negative timestamps when decoding Vorbis
  83   // audio, for example.
  84   int output_bytes_to_drop_;
  85
  86   typedef std::vector<uint8_t> SerializedAudioFrames;
  87   SerializedAudioFrames serialized_audio_frames_;
  88
  89   DISALLOW_COPY_AND_ASSIGN(FFmpegCdmAudioDecoder);
  90 };
  91
  92 }  // namespace media
  93
  94 #endif  // MEDIA_CDM_PPAPI_EXTERNAL_CLEAR_KEY_FFMPEG_CDM_AUDIO_DECODER_H_