media/audio/audio_output_controller.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_controller.h"
   6
   7 #include "base/bind.h"
   8 #include "base/debug/trace_event.h"
   9 #include "base/metrics/histogram.h"
  10 #include "base/task_runner_util.h"
  11 #include "base/threading/platform_thread.h"
  12 #include "base/time/time.h"
  13 #include "build/build_config.h"
  14 #include "media/base/scoped_histogram_timer.h"
  15
  16 using base::TimeDelta;
  17
  18 namespace media {
  19
  20 #if defined(AUDIO_POWER_MONITORING)
  21 // Time constant for AudioPowerMonitor.  See AudioPowerMonitor ctor comments for
  22 // semantics.  This value was arbitrarily chosen, but seems to work well.
  23 static const int kPowerMeasurementTimeConstantMillis = 10;
  24 #endif
  25
  26 AudioOutputController::AudioOutputController(
  27     AudioManager* audio_manager,
  28     EventHandler* handler,
  29     const AudioParameters& params,
  30     const std::string& output_device_id,
  31     SyncReader* sync_reader)
  32     : audio_manager_(audio_manager),
  33       params_(params),
  34       handler_(handler),
  35       output_device_id_(output_device_id),
  36       stream_(NULL),
  37       diverting_to_stream_(NULL),
  38       volume_(1.0),
  39       state_(kEmpty),
  40       sync_reader_(sync_reader),
  41       message_loop_(audio_manager->GetTaskRunner()),
  42 #if defined(AUDIO_POWER_MONITORING)
  43       power_monitor_(
  44           params.sample_rate(),
  45           TimeDelta::FromMilliseconds(kPowerMeasurementTimeConstantMillis)),
  46 #endif
  47       on_more_io_data_called_(0) {
  48   DCHECK(audio_manager);
  49   DCHECK(handler_);
  50   DCHECK(sync_reader_);
  51   DCHECK(message_loop_.get());
  52 }
  53
  54 AudioOutputController::~AudioOutputController() {
  55   DCHECK_EQ(kClosed, state_);
  56 }
  57
  58 // static
  59 scoped_refptr<AudioOutputController> AudioOutputController::Create(
  60     AudioManager* audio_manager,
  61     EventHandler* event_handler,
  62     const AudioParameters& params,
  63     const std::string& output_device_id,
  64     SyncReader* sync_reader) {
  65   DCHECK(audio_manager);
  66   DCHECK(sync_reader);
  67
  68   if (!params.IsValid() || !audio_manager)
  69     return NULL;
  70
  71   scoped_refptr<AudioOutputController> controller(new AudioOutputController(
  72       audio_manager, event_handler, params, output_device_id, sync_reader));
  73   controller->message_loop_->PostTask(FROM_HERE, base::Bind(
  74       &AudioOutputController::DoCreate, controller, false));
  75   return controller;
  76 }
  77
  78 void AudioOutputController::Play() {
  79   message_loop_->PostTask(FROM_HERE, base::Bind(
  80       &AudioOutputController::DoPlay, this));
  81 }
  82
  83 void AudioOutputController::Pause() {
  84   message_loop_->PostTask(FROM_HERE, base::Bind(
  85       &AudioOutputController::DoPause, this));
  86 }
  87
  88 void AudioOutputController::Close(const base::Closure& closed_task) {
  89   DCHECK(!closed_task.is_null());
  90   message_loop_->PostTaskAndReply(FROM_HERE, base::Bind(
  91       &AudioOutputController::DoClose, this), closed_task);
  92 }
  93
  94 void AudioOutputController::SetVolume(double volume) {
  95   message_loop_->PostTask(FROM_HERE, base::Bind(
  96       &AudioOutputController::DoSetVolume, this, volume));
  97 }
  98
  99 void AudioOutputController::GetOutputDeviceId(
 100     base::Callback<void(const std::string&)> callback) const {
 101   base::PostTaskAndReplyWithResult(
 102       message_loop_.get(),
 103       FROM_HERE,
 104       base::Bind(&AudioOutputController::DoGetOutputDeviceId, this),
 105       callback);
 106 }
 107
 108 void AudioOutputController::SwitchOutputDevice(
 109     const std::string& output_device_id, const base::Closure& callback) {
 110   message_loop_->PostTaskAndReply(
 111       FROM_HERE,
 112       base::Bind(&AudioOutputController::DoSwitchOutputDevice, this,
 113                  output_device_id),
 114       callback);
 115 }
 116
 117 void AudioOutputController::DoCreate(bool is_for_device_change) {
 118   DCHECK(message_loop_->BelongsToCurrentThread());
 119   SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioOutputController.CreateTime");
 120   TRACE_EVENT0("audio", "AudioOutputController::DoCreate");
 121
 122   // Close() can be called before DoCreate() is executed.
 123   if (state_ == kClosed)
 124     return;
 125
 126   DoStopCloseAndClearStream();  // Calls RemoveOutputDeviceChangeListener().
 127   DCHECK_EQ(kEmpty, state_);
 128
 129   stream_ = diverting_to_stream_ ?
 130       diverting_to_stream_ :
 131       audio_manager_->MakeAudioOutputStreamProxy(params_, output_device_id_);
 132   if (!stream_) {
 133     state_ = kError;
 134     handler_->OnError();
 135     return;
 136   }
 137
 138   if (!stream_->Open()) {
 139     DoStopCloseAndClearStream();
 140     state_ = kError;
 141     handler_->OnError();
 142     return;
 143   }
 144
 145   // Everything started okay, so re-register for state change callbacks if
 146   // stream_ was created via AudioManager.
 147   if (stream_ != diverting_to_stream_)
 148     audio_manager_->AddOutputDeviceChangeListener(this);
 149
 150   // We have successfully opened the stream. Set the initial volume.
 151   stream_->SetVolume(volume_);
 152
 153   // Finally set the state to kCreated.
 154   state_ = kCreated;
 155
 156   // And then report we have been created if we haven't done so already.
 157   if (!is_for_device_change)
 158     handler_->OnCreated();
 159 }
 160
 161 void AudioOutputController::DoPlay() {
 162   DCHECK(message_loop_->BelongsToCurrentThread());
 163   SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioOutputController.PlayTime");
 164   TRACE_EVENT0("audio", "AudioOutputController::DoPlay");
 165
 166   // We can start from created or paused state.
 167   if (state_ != kCreated && state_ != kPaused)
 168     return;
 169
 170   // Ask for first packet.
 171   sync_reader_->UpdatePendingBytes(0);
 172
 173   state_ = kPlaying;
 174
 175   stream_->Start(this);
 176
 177   // For UMA tracking purposes, start the wedge detection timer.  This allows us
 178   // to record statistics about the number of wedged playbacks in the field.
 179   //
 180   // WedgeCheck() will look to see if |on_more_io_data_called_| is true after
 181   // the timeout expires.  Care must be taken to ensure the wedge check delay is
 182   // large enough that the value isn't queried while OnMoreDataIO() is setting
 183   // it.
 184   //
 185   // Timer self-manages its lifetime and WedgeCheck() will only record the UMA
 186   // statistic if state is still kPlaying.  Additional Start() calls will
 187   // invalidate the previous timer.
 188   wedge_timer_.reset(new base::OneShotTimer<AudioOutputController>());
 189   wedge_timer_->Start(
 190       FROM_HERE, TimeDelta::FromSeconds(5), this,
 191       &AudioOutputController::WedgeCheck);
 192
 193   handler_->OnPlaying();
 194 }
 195
 196 void AudioOutputController::StopStream() {
 197   DCHECK(message_loop_->BelongsToCurrentThread());
 198
 199   if (state_ == kPlaying) {
 200     wedge_timer_.reset();
 201     stream_->Stop();
 202
 203 #if defined(AUDIO_POWER_MONITORING)
 204     // A stopped stream is silent, and power_montior_.Scan() is no longer being
 205     // called; so we must reset the power monitor.
 206     power_monitor_.Reset();
 207 #endif
 208
 209     state_ = kPaused;
 210   }
 211 }
 212
 213 void AudioOutputController::DoPause() {
 214   DCHECK(message_loop_->BelongsToCurrentThread());
 215   SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioOutputController.PauseTime");
 216   TRACE_EVENT0("audio", "AudioOutputController::DoPause");
 217
 218   StopStream();
 219
 220   if (state_ != kPaused)
 221     return;
 222
 223   // Let the renderer know we've stopped.  Necessary to let PPAPI clients know
 224   // audio has been shutdown.  TODO(dalecurtis): This stinks.  PPAPI should have
 225   // a better way to know when it should exit PPB_Audio_Shared::Run().
 226   sync_reader_->UpdatePendingBytes(-1);
 227
 228   handler_->OnPaused();
 229 }
 230
 231 void AudioOutputController::DoClose() {
 232   DCHECK(message_loop_->BelongsToCurrentThread());
 233   SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioOutputController.CloseTime");
 234   TRACE_EVENT0("audio", "AudioOutputController::DoClose");
 235
 236   if (state_ != kClosed) {
 237     DoStopCloseAndClearStream();
 238     sync_reader_->Close();
 239     state_ = kClosed;
 240   }
 241 }
 242
 243 void AudioOutputController::DoSetVolume(double volume) {
 244   DCHECK(message_loop_->BelongsToCurrentThread());
 245
 246   // Saves the volume to a member first. We may not be able to set the volume
 247   // right away but when the stream is created we'll set the volume.
 248   volume_ = volume;
 249
 250   switch (state_) {
 251     case kCreated:
 252     case kPlaying:
 253     case kPaused:
 254       stream_->SetVolume(volume_);
 255       break;
 256     default:
 257       return;
 258   }
 259 }
 260
 261 std::string AudioOutputController::DoGetOutputDeviceId() const {
 262   DCHECK(message_loop_->BelongsToCurrentThread());
 263   return output_device_id_;
 264 }
 265
 266 void AudioOutputController::DoSwitchOutputDevice(
 267     const std::string& output_device_id) {
 268   DCHECK(message_loop_->BelongsToCurrentThread());
 269
 270   if (state_ == kClosed)
 271     return;
 272
 273   if (output_device_id == output_device_id_)
 274     return;
 275
 276   output_device_id_ = output_device_id;
 277
 278   // If output is currently diverted, we must not call OnDeviceChange
 279   // since it would break the diverted setup. Once diversion is
 280   // finished using StopDiverting() the output will switch to the new
 281   // device ID.
 282   if (stream_ != diverting_to_stream_)
 283     OnDeviceChange();
 284 }
 285
 286 void AudioOutputController::DoReportError() {
 287   DCHECK(message_loop_->BelongsToCurrentThread());
 288   if (state_ != kClosed)
 289     handler_->OnError();
 290 }
 291
 292 int AudioOutputController::OnMoreData(AudioBus* dest,
 293                                       AudioBuffersState buffers_state) {
 294   TRACE_EVENT0("audio", "AudioOutputController::OnMoreData");
 295
 296   // Indicate that we haven't wedged (at least not indefinitely, WedgeCheck()
 297   // may have already fired if OnMoreIOData() took an abnormal amount of time).
 298   // Since this thread is the only writer of |on_more_io_data_called_| once the
 299   // thread starts, its safe to compare and then increment.
 300   if (base::AtomicRefCountIsZero(&on_more_io_data_called_))
 301     base::AtomicRefCountInc(&on_more_io_data_called_);
 302
 303   sync_reader_->Read(dest);
 304
 305   const int frames = dest->frames();
 306   sync_reader_->UpdatePendingBytes(
 307       buffers_state.total_bytes() + frames * params_.GetBytesPerFrame());
 308
 309 #if defined(AUDIO_POWER_MONITORING)
 310   power_monitor_.Scan(*dest, frames);
 311 #endif
 312
 313   return frames;
 314 }
 315
 316 void AudioOutputController::OnError(AudioOutputStream* stream) {
 317   // Handle error on the audio controller thread.
 318   message_loop_->PostTask(FROM_HERE, base::Bind(
 319       &AudioOutputController::DoReportError, this));
 320 }
 321
 322 void AudioOutputController::DoStopCloseAndClearStream() {
 323   DCHECK(message_loop_->BelongsToCurrentThread());
 324
 325   // Allow calling unconditionally and bail if we don't have a stream_ to close.
 326   if (stream_) {
 327     // De-register from state change callbacks if stream_ was created via
 328     // AudioManager.
 329     if (stream_ != diverting_to_stream_)
 330       audio_manager_->RemoveOutputDeviceChangeListener(this);
 331
 332     StopStream();
 333     stream_->Close();
 334     if (stream_ == diverting_to_stream_)
 335       diverting_to_stream_ = NULL;
 336     stream_ = NULL;
 337   }
 338
 339   state_ = kEmpty;
 340 }
 341
 342 void AudioOutputController::OnDeviceChange() {
 343   DCHECK(message_loop_->BelongsToCurrentThread());
 344   SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioOutputController.DeviceChangeTime");
 345   TRACE_EVENT0("audio", "AudioOutputController::OnDeviceChange");
 346
 347   // TODO(dalecurtis): Notify the renderer side that a device change has
 348   // occurred.  Currently querying the hardware information here will lead to
 349   // crashes on OSX.  See http://crbug.com/158170.
 350
 351   // Recreate the stream (DoCreate() will first shut down an existing stream).
 352   // Exit if we ran into an error.
 353   const State original_state = state_;
 354   DoCreate(true);
 355   if (!stream_ || state_ == kError)
 356     return;
 357
 358   // Get us back to the original state or an equivalent state.
 359   switch (original_state) {
 360     case kPlaying:
 361       DoPlay();
 362       return;
 363     case kCreated:
 364     case kPaused:
 365       // From the outside these two states are equivalent.
 366       return;
 367     default:
 368       NOTREACHED() << "Invalid original state.";
 369   }
 370 }
 371
 372 const AudioParameters& AudioOutputController::GetAudioParameters() {
 373   return params_;
 374 }
 375
 376 void AudioOutputController::StartDiverting(AudioOutputStream* to_stream) {
 377   message_loop_->PostTask(
 378       FROM_HERE,
 379       base::Bind(&AudioOutputController::DoStartDiverting, this, to_stream));
 380 }
 381
 382 void AudioOutputController::StopDiverting() {
 383   message_loop_->PostTask(
 384       FROM_HERE, base::Bind(&AudioOutputController::DoStopDiverting, this));
 385 }
 386
 387 void AudioOutputController::DoStartDiverting(AudioOutputStream* to_stream) {
 388   DCHECK(message_loop_->BelongsToCurrentThread());
 389
 390   if (state_ == kClosed)
 391     return;
 392
 393   DCHECK(!diverting_to_stream_);
 394   diverting_to_stream_ = to_stream;
 395   // Note: OnDeviceChange() will engage the "re-create" process, which will
 396   // detect and use the alternate AudioOutputStream rather than create a new one
 397   // via AudioManager.
 398   OnDeviceChange();
 399 }
 400
 401 void AudioOutputController::DoStopDiverting() {
 402   DCHECK(message_loop_->BelongsToCurrentThread());
 403
 404   if (state_ == kClosed)
 405     return;
 406
 407   // Note: OnDeviceChange() will cause the existing stream (the consumer of the
 408   // diverted audio data) to be closed, and diverting_to_stream_ will be set
 409   // back to NULL.
 410   OnDeviceChange();
 411   DCHECK(!diverting_to_stream_);
 412 }
 413
 414 std::pair<float, bool> AudioOutputController::ReadCurrentPowerAndClip() {
 415 #if defined(AUDIO_POWER_MONITORING)
 416   return power_monitor_.ReadCurrentPowerAndClip();
 417 #else
 418   NOTREACHED();
 419   return std::make_pair(AudioPowerMonitor::zero_power(), false);
 420 #endif
 421 }
 422
 423 void AudioOutputController::WedgeCheck() {
 424   DCHECK(message_loop_->BelongsToCurrentThread());
 425
 426   // If we should be playing and we haven't, that's a wedge.
 427   if (state_ == kPlaying) {
 428     UMA_HISTOGRAM_BOOLEAN("Media.AudioOutputControllerPlaybackStartupSuccess",
 429                           base::AtomicRefCountIsOne(&on_more_io_data_called_));
 430   }
 431 }
 432
 433 }  // namespace media