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