src/media/audio/audio_output_dispatcher_impl.cc

   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 #include "media/audio/audio_output_dispatcher_impl.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/compiler_specific.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/time/time.h"
  13 #include "media/audio/audio_io.h"
  14 #include "media/audio/audio_output_proxy.h"
  15
  16 namespace media {
  17
  18 AudioOutputDispatcherImpl::AudioOutputDispatcherImpl(
  19     AudioManager* audio_manager,
  20     const AudioParameters& params,
  21     const std::string& output_device_id,
  22     const std::string& input_device_id,
  23     const base::TimeDelta& close_delay)
  24     : AudioOutputDispatcher(audio_manager, params, output_device_id,
  25           input_device_id),
  26       pause_delay_(base::TimeDelta::FromMicroseconds(
  27           2 * params.frames_per_buffer() * base::Time::kMicrosecondsPerSecond /
  28           static_cast<float>(params.sample_rate()))),
  29       paused_proxies_(0),
  30       weak_this_(this),
  31       close_timer_(FROM_HERE,
  32                    close_delay,
  33                    this,
  34                    &AudioOutputDispatcherImpl::ClosePendingStreams) {
  35 }
  36
  37 AudioOutputDispatcherImpl::~AudioOutputDispatcherImpl() {
  38   DCHECK(proxy_to_physical_map_.empty());
  39   DCHECK(idle_streams_.empty());
  40   DCHECK(pausing_streams_.empty());
  41 }
  42
  43 bool AudioOutputDispatcherImpl::OpenStream() {
  44   DCHECK(message_loop_->BelongsToCurrentThread());
  45
  46   paused_proxies_++;
  47
  48   // Ensure that there is at least one open stream.
  49   if (idle_streams_.empty() && !CreateAndOpenStream()) {
  50     paused_proxies_--;
  51     return false;
  52   }
  53
  54   close_timer_.Reset();
  55   return true;
  56 }
  57
  58 bool AudioOutputDispatcherImpl::StartStream(
  59     AudioOutputStream::AudioSourceCallback* callback,
  60     AudioOutputProxy* stream_proxy) {
  61   DCHECK(message_loop_->BelongsToCurrentThread());
  62
  63   if (idle_streams_.empty() && !CreateAndOpenStream())
  64     return false;
  65
  66   AudioOutputStream* physical_stream = idle_streams_.back();
  67   DCHECK(physical_stream);
  68   idle_streams_.pop_back();
  69
  70   DCHECK_GT(paused_proxies_, 0u);
  71   --paused_proxies_;
  72
  73   close_timer_.Reset();
  74
  75   double volume = 0;
  76   stream_proxy->GetVolume(&volume);
  77   physical_stream->SetVolume(volume);
  78   physical_stream->Start(callback);
  79   proxy_to_physical_map_[stream_proxy] = physical_stream;
  80   return true;
  81 }
  82
  83 void AudioOutputDispatcherImpl::StopStream(AudioOutputProxy* stream_proxy) {
  84   DCHECK(message_loop_->BelongsToCurrentThread());
  85
  86   AudioStreamMap::iterator it = proxy_to_physical_map_.find(stream_proxy);
  87   DCHECK(it != proxy_to_physical_map_.end());
  88   AudioOutputStream* physical_stream = it->second;
  89   proxy_to_physical_map_.erase(it);
  90
  91   physical_stream->Stop();
  92
  93   ++paused_proxies_;
  94
  95   pausing_streams_.push_front(physical_stream);
  96
  97   // Don't recycle stream until two buffers worth of time has elapsed.
  98   message_loop_->PostDelayedTask(
  99       FROM_HERE,
 100       base::Bind(&AudioOutputDispatcherImpl::StopStreamTask,
 101                  weak_this_.GetWeakPtr()),
 102       pause_delay_);
 103 }
 104
 105 void AudioOutputDispatcherImpl::StreamVolumeSet(AudioOutputProxy* stream_proxy,
 106                                                 double volume) {
 107   DCHECK(message_loop_->BelongsToCurrentThread());
 108   AudioStreamMap::iterator it = proxy_to_physical_map_.find(stream_proxy);
 109   if (it != proxy_to_physical_map_.end()) {
 110     AudioOutputStream* physical_stream = it->second;
 111     physical_stream->SetVolume(volume);
 112   }
 113 }
 114
 115 void AudioOutputDispatcherImpl::StopStreamTask() {
 116   DCHECK(message_loop_->BelongsToCurrentThread());
 117
 118   if (pausing_streams_.empty())
 119     return;
 120
 121   AudioOutputStream* stream = pausing_streams_.back();
 122   pausing_streams_.pop_back();
 123   idle_streams_.push_back(stream);
 124   close_timer_.Reset();
 125 }
 126
 127 void AudioOutputDispatcherImpl::CloseStream(AudioOutputProxy* stream_proxy) {
 128   DCHECK(message_loop_->BelongsToCurrentThread());
 129
 130   while (!pausing_streams_.empty()) {
 131     idle_streams_.push_back(pausing_streams_.back());
 132     pausing_streams_.pop_back();
 133   }
 134
 135   DCHECK_GT(paused_proxies_, 0u);
 136   paused_proxies_--;
 137
 138   while (idle_streams_.size() > paused_proxies_) {
 139     idle_streams_.back()->Close();
 140     idle_streams_.pop_back();
 141   }
 142 }
 143
 144 void AudioOutputDispatcherImpl::Shutdown() {
 145   DCHECK(message_loop_->BelongsToCurrentThread());
 146
 147   // Cancel any pending tasks to close paused streams or create new ones.
 148   weak_this_.InvalidateWeakPtrs();
 149
 150   // No AudioOutputProxy objects should hold a reference to us when we get
 151   // to this stage.
 152   DCHECK(HasOneRef()) << "Only the AudioManager should hold a reference";
 153
 154   AudioOutputStreamList::iterator it = idle_streams_.begin();
 155   for (; it != idle_streams_.end(); ++it)
 156     (*it)->Close();
 157   idle_streams_.clear();
 158
 159   it = pausing_streams_.begin();
 160   for (; it != pausing_streams_.end(); ++it)
 161     (*it)->Close();
 162   pausing_streams_.clear();
 163 }
 164
 165 bool AudioOutputDispatcherImpl::CreateAndOpenStream() {
 166   DCHECK(message_loop_->BelongsToCurrentThread());
 167   AudioOutputStream* stream = audio_manager_->MakeAudioOutputStream(
 168       params_, output_device_id_, input_device_id_);
 169   if (!stream)
 170     return false;
 171
 172   if (!stream->Open()) {
 173     stream->Close();
 174     return false;
 175   }
 176   idle_streams_.push_back(stream);
 177   return true;
 178 }
 179
 180 // This method is called by |close_timer_|.
 181 void AudioOutputDispatcherImpl::ClosePendingStreams() {
 182   DCHECK(message_loop_->BelongsToCurrentThread());
 183   while (!idle_streams_.empty()) {
 184     idle_streams_.back()->Close();
 185     idle_streams_.pop_back();
 186   }
 187 }
 188
 189 }  // namespace media