webkit/media/crypto/ppapi/ffmpeg_cdm_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 WEBKIT_MEDIA_CRYPTO_PPAPI_FFMPEG_CDM_AUDIO_DECODER_H_
   6 #define WEBKIT_MEDIA_CRYPTO_PPAPI_FFMPEG_CDM_AUDIO_DECODER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/time.h"
  13 #include "base/compiler_specific.h"
  14 #include "webkit/media/crypto/ppapi/cdm/content_decryption_module.h"
  15
  16 struct AVCodecContext;
  17 struct AVFrame;
  18
  19 namespace media {
  20 class AudioBus;
  21 class AudioTimestampHelper;
  22 }
  23
  24 namespace webkit_media {
  25
  26 // TODO(xhwang): This class is partially cloned from media::FFmpegAudioDecoder.
  27 // When media::FFmpegAudioDecoder is updated, it's a pain to keep this class
  28 // in sync with media::FFmpegAudioDecoder. We need a long term sustainable
  29 // solution for this. See http://crbug.com/169203
  30 class FFmpegCdmAudioDecoder {
  31  public:
  32   explicit FFmpegCdmAudioDecoder(cdm::Host* 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   cdm::Host* const host_;
  64
  65   // FFmpeg structures owned by this object.
  66   AVCodecContext* codec_context_;
  67   AVFrame* av_frame_;
  68
  69   // Audio format.
  70   int bits_per_channel_;
  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<media::AudioTimestampHelper> output_timestamp_helper_;
  79   int bytes_per_frame_;
  80   base::TimeDelta last_input_timestamp_;
  81
  82   // We may need to convert the audio data coming out of FFmpeg from planar
  83   // float to integer.
  84   scoped_ptr<media::AudioBus> converter_bus_;
  85
  86   // Number of output sample bytes to drop before generating output buffers.
  87   // This is required for handling negative timestamps when decoding Vorbis
  88   // audio, for example.
  89   int output_bytes_to_drop_;
  90
  91   typedef std::vector<uint8_t> SerializedAudioFrames;
  92   SerializedAudioFrames serialized_audio_frames_;
  93
  94   DISALLOW_COPY_AND_ASSIGN(FFmpegCdmAudioDecoder);
  95 };
  96
  97 }  // namespace webkit_media
  98
  99 #endif  // WEBKIT_MEDIA_CRYPTO_PPAPI_FFMPEG_CDM_AUDIO_DECODER_H_