media/audio/audio_output_stream_sink.cc

   1 // Copyright 2014 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/audio/audio_output_stream_sink.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/location.h"
  10 #include "media/audio/audio_manager.h"
  11
  12 namespace media {
  13
  14 AudioOutputStreamSink::AudioOutputStreamSink()
  15     : render_callback_(NULL),
  16       audio_task_runner_(AudioManager::Get()->GetTaskRunner()),
  17       stream_(NULL),
  18       active_render_callback_(NULL) {
  19 }
  20
  21 AudioOutputStreamSink::~AudioOutputStreamSink() {
  22 }
  23
  24 void AudioOutputStreamSink::Initialize(const AudioParameters& params,
  25                                        RenderCallback* callback) {
  26   DCHECK(callback);
  27   DCHECK(!render_callback_);
  28   params_ = params;
  29   render_callback_ = callback;
  30 }
  31
  32 void AudioOutputStreamSink::Start() {
  33   audio_task_runner_->PostTask(
  34       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoStart, this));
  35 }
  36
  37 void AudioOutputStreamSink::Stop() {
  38   ClearCallback();
  39   audio_task_runner_->PostTask(
  40       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoStop, this));
  41 }
  42
  43 void AudioOutputStreamSink::Pause() {
  44   ClearCallback();
  45   audio_task_runner_->PostTask(
  46       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoPause, this));
  47 }
  48
  49 void AudioOutputStreamSink::Play() {
  50   base::AutoLock al(callback_lock_);
  51   active_render_callback_ = render_callback_;
  52   audio_task_runner_->PostTask(
  53       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoPlay, this));
  54 }
  55
  56 bool AudioOutputStreamSink::SetVolume(double volume) {
  57   audio_task_runner_->PostTask(
  58       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoSetVolume, this, volume));
  59   return true;
  60 };
  61
  62 int AudioOutputStreamSink::OnMoreData(AudioBus* dest,
  63                                       uint32 total_bytes_delay) {
  64   // Note: Runs on the audio thread created by the OS.
  65   base::AutoLock al(callback_lock_);
  66   if (!active_render_callback_)
  67     return 0;
  68
  69   return active_render_callback_->Render(
  70       dest, total_bytes_delay * 1000.0 / params_.GetBytesPerSecond());
  71 }
  72
  73 void AudioOutputStreamSink::OnError(AudioOutputStream* stream) {
  74   // Note: Runs on the audio thread created by the OS.
  75   base::AutoLock al(callback_lock_);
  76   if (active_render_callback_)
  77     active_render_callback_->OnRenderError();
  78 }
  79
  80 void AudioOutputStreamSink::DoStart() {
  81   DCHECK(audio_task_runner_->BelongsToCurrentThread());
  82
  83   // Create an AudioOutputStreamProxy which will handle any and all resampling
  84   // necessary to generate a low latency output stream.
  85   stream_ =
  86       AudioManager::Get()->MakeAudioOutputStreamProxy(params_, std::string());
  87   if (!stream_ || !stream_->Open()) {
  88     render_callback_->OnRenderError();
  89     if (stream_)
  90       stream_->Close();
  91     stream_ = NULL;
  92   }
  93 }
  94
  95 void AudioOutputStreamSink::DoStop() {
  96   DCHECK(audio_task_runner_->BelongsToCurrentThread());
  97
  98   if (!stream_)
  99     return;
 100
 101   DoPause();
 102   stream_->Close();
 103   stream_ = NULL;
 104 }
 105
 106 void AudioOutputStreamSink::DoPause() {
 107   DCHECK(audio_task_runner_->BelongsToCurrentThread());
 108   stream_->Stop();
 109 }
 110
 111 void AudioOutputStreamSink::DoPlay() {
 112   DCHECK(audio_task_runner_->BelongsToCurrentThread());
 113   stream_->Start(this);
 114 }
 115
 116 void AudioOutputStreamSink::DoSetVolume(double volume) {
 117   DCHECK(audio_task_runner_->BelongsToCurrentThread());
 118   stream_->SetVolume(volume);
 119 }
 120
 121 void AudioOutputStreamSink::ClearCallback() {
 122   base::AutoLock al(callback_lock_);
 123   active_render_callback_ = NULL;
 124 }
 125
 126 }  // namepace media