media/base/android/audio_decoder_job.cc

   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 #include "media/base/android/audio_decoder_job.h"
   6
   7 #include "base/bind.h"
   8 #include "base/lazy_instance.h"
   9 #include "base/threading/thread.h"
  10 #include "media/base/android/media_codec_bridge.h"
  11 #include "media/base/audio_timestamp_helper.h"
  12
  13 namespace {
  14
  15 // Use 16bit PCM for audio output. Keep this value in sync with the output
  16 // format we passed to AudioTrack in MediaCodecBridge.
  17 const int kBytesPerAudioOutputSample = 2;
  18 }
  19
  20 namespace media {
  21
  22 class AudioDecoderThread : public base::Thread {
  23  public:
  24   AudioDecoderThread() : base::Thread("MediaSource_AudioDecoderThread") {
  25     Start();
  26   }
  27 };
  28
  29 // TODO(qinmin): Check if it is tolerable to use worker pool to handle all the
  30 // decoding tasks so that we don't need a global thread here.
  31 // http://crbug.com/245750
  32 base::LazyInstance<AudioDecoderThread>::Leaky
  33     g_audio_decoder_thread = LAZY_INSTANCE_INITIALIZER;
  34
  35 AudioDecoderJob* AudioDecoderJob::Create(
  36     const AudioCodec audio_codec,
  37     int sample_rate,
  38     int channel_count,
  39     const uint8* extra_data,
  40     size_t extra_data_size,
  41     jobject media_crypto,
  42     const base::Closure& request_data_cb) {
  43   scoped_ptr<AudioCodecBridge> codec(AudioCodecBridge::Create(audio_codec));
  44   if (codec && codec->Start(audio_codec, sample_rate, channel_count, extra_data,
  45                             extra_data_size, true, media_crypto)) {
  46     scoped_ptr<AudioTimestampHelper> audio_timestamp_helper(
  47         new AudioTimestampHelper(sample_rate));
  48     return new AudioDecoderJob(
  49         audio_timestamp_helper.Pass(), codec.Pass(),
  50         kBytesPerAudioOutputSample * channel_count, request_data_cb);
  51   }
  52   LOG(ERROR) << "Failed to create AudioDecoderJob.";
  53   return NULL;
  54 }
  55
  56 AudioDecoderJob::AudioDecoderJob(
  57     scoped_ptr<AudioTimestampHelper> audio_timestamp_helper,
  58     scoped_ptr<AudioCodecBridge> audio_codec_bridge,
  59     int bytes_per_frame,
  60     const base::Closure& request_data_cb)
  61     : MediaDecoderJob(g_audio_decoder_thread.Pointer()->message_loop_proxy(),
  62                       audio_codec_bridge.get(), request_data_cb),
  63       bytes_per_frame_(bytes_per_frame),
  64       audio_codec_bridge_(audio_codec_bridge.Pass()),
  65       audio_timestamp_helper_(audio_timestamp_helper.Pass()) {
  66 }
  67
  68 AudioDecoderJob::~AudioDecoderJob() {
  69 }
  70
  71 void AudioDecoderJob::SetVolume(double volume) {
  72   audio_codec_bridge_->SetVolume(volume);
  73 }
  74
  75 void AudioDecoderJob::SetBaseTimestamp(base::TimeDelta base_timestamp) {
  76   audio_timestamp_helper_->SetBaseTimestamp(base_timestamp);
  77 }
  78
  79 void AudioDecoderJob::ReleaseOutputBuffer(
  80     int output_buffer_index,
  81     size_t size,
  82     bool render_output,
  83     base::TimeDelta current_presentation_timestamp,
  84     const ReleaseOutputCompletionCallback& callback) {
  85   render_output = render_output && (size != 0u);
  86   if (render_output) {
  87     int64 head_position = audio_codec_bridge_->PlayOutputBuffer(
  88         output_buffer_index, size);
  89     audio_timestamp_helper_->AddFrames(size / (bytes_per_frame_));
  90     int64 frames_to_play =
  91         audio_timestamp_helper_->frame_count() - head_position;
  92     DCHECK_GE(frames_to_play, 0);
  93     current_presentation_timestamp =
  94         audio_timestamp_helper_->GetTimestamp() -
  95         audio_timestamp_helper_->GetFrameDuration(frames_to_play);
  96   } else {
  97     current_presentation_timestamp = kNoTimestamp();
  98   }
  99   audio_codec_bridge_->ReleaseOutputBuffer(output_buffer_index, false);
 100   callback.Run(current_presentation_timestamp,
 101                audio_timestamp_helper_->GetTimestamp());
 102 }
 103
 104 bool AudioDecoderJob::ComputeTimeToRender() const {
 105   return false;
 106 }
 107
 108 }  // namespace media