media/audio/audio_output_device.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_device.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/debug/trace_event.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "base/threading/thread_restrictions.h"
  11 #include "base/time/time.h"
  12 #include "media/audio/audio_output_controller.h"
  13 #include "media/audio/audio_util.h"
  14 #include "media/audio/shared_memory_util.h"
  15 #include "media/base/limits.h"
  16
  17 namespace media {
  18
  19 // Takes care of invoking the render callback on the audio thread.
  20 // An instance of this class is created for each capture stream in
  21 // OnStreamCreated().
  22 class AudioOutputDevice::AudioThreadCallback
  23     : public AudioDeviceThread::Callback {
  24  public:
  25   AudioThreadCallback(const AudioParameters& audio_parameters,
  26                       base::SharedMemoryHandle memory,
  27                       int memory_length,
  28                       AudioRendererSink::RenderCallback* render_callback);
  29   virtual ~AudioThreadCallback();
  30
  31   virtual void MapSharedMemory() OVERRIDE;
  32
  33   // Called whenever we receive notifications about pending data.
  34   virtual void Process(int pending_data) OVERRIDE;
  35
  36  private:
  37   AudioRendererSink::RenderCallback* render_callback_;
  38   scoped_ptr<AudioBus> input_bus_;
  39   scoped_ptr<AudioBus> output_bus_;
  40   DISALLOW_COPY_AND_ASSIGN(AudioThreadCallback);
  41 };
  42
  43 AudioOutputDevice::AudioOutputDevice(
  44     scoped_ptr<AudioOutputIPC> ipc,
  45     const scoped_refptr<base::MessageLoopProxy>& io_loop)
  46     : ScopedLoopObserver(io_loop),
  47       callback_(NULL),
  48       ipc_(ipc.Pass()),
  49       state_(IDLE),
  50       play_on_start_(true),
  51       session_id_(-1),
  52       stopping_hack_(false) {
  53   CHECK(ipc_);
  54
  55   // The correctness of the code depends on the relative values assigned in the
  56   // State enum.
  57   COMPILE_ASSERT(IPC_CLOSED < IDLE, invalid_enum_value_assignment_0);
  58   COMPILE_ASSERT(IDLE < CREATING_STREAM, invalid_enum_value_assignment_1);
  59   COMPILE_ASSERT(CREATING_STREAM < PAUSED, invalid_enum_value_assignment_2);
  60   COMPILE_ASSERT(PAUSED < PLAYING, invalid_enum_value_assignment_3);
  61 }
  62
  63 void AudioOutputDevice::InitializeUnifiedStream(const AudioParameters& params,
  64                                                 RenderCallback* callback,
  65                                                 int session_id) {
  66   DCHECK(!callback_) << "Calling InitializeUnifiedStream() twice?";
  67   DCHECK(params.IsValid());
  68   audio_parameters_ = params;
  69   callback_ = callback;
  70   session_id_ = session_id;
  71 }
  72
  73 void AudioOutputDevice::Initialize(const AudioParameters& params,
  74                                    RenderCallback* callback) {
  75   InitializeUnifiedStream(params, callback, 0);
  76 }
  77
  78 AudioOutputDevice::~AudioOutputDevice() {
  79   // The current design requires that the user calls Stop() before deleting
  80   // this class.
  81   DCHECK(audio_thread_.IsStopped());
  82 }
  83
  84 void AudioOutputDevice::Start() {
  85   DCHECK(callback_) << "Initialize hasn't been called";
  86   message_loop()->PostTask(FROM_HERE,
  87       base::Bind(&AudioOutputDevice::CreateStreamOnIOThread, this,
  88                  audio_parameters_));
  89 }
  90
  91 void AudioOutputDevice::Stop() {
  92   {
  93     base::AutoLock auto_lock(audio_thread_lock_);
  94     audio_thread_.Stop(base::MessageLoop::current());
  95     stopping_hack_ = true;
  96   }
  97
  98   message_loop()->PostTask(FROM_HERE,
  99       base::Bind(&AudioOutputDevice::ShutDownOnIOThread, this));
 100 }
 101
 102 void AudioOutputDevice::Play() {
 103   message_loop()->PostTask(FROM_HERE,
 104       base::Bind(&AudioOutputDevice::PlayOnIOThread, this));
 105 }
 106
 107 void AudioOutputDevice::Pause() {
 108   message_loop()->PostTask(FROM_HERE,
 109       base::Bind(&AudioOutputDevice::PauseOnIOThread, this));
 110 }
 111
 112 bool AudioOutputDevice::SetVolume(double volume) {
 113   if (volume < 0 || volume > 1.0)
 114     return false;
 115
 116   if (!message_loop()->PostTask(FROM_HERE,
 117           base::Bind(&AudioOutputDevice::SetVolumeOnIOThread, this, volume))) {
 118     return false;
 119   }
 120
 121   return true;
 122 }
 123
 124 void AudioOutputDevice::CreateStreamOnIOThread(const AudioParameters& params) {
 125   DCHECK(message_loop()->BelongsToCurrentThread());
 126   if (state_ == IDLE) {
 127     state_ = CREATING_STREAM;
 128     ipc_->CreateStream(this, params, session_id_);
 129   }
 130 }
 131
 132 void AudioOutputDevice::PlayOnIOThread() {
 133   DCHECK(message_loop()->BelongsToCurrentThread());
 134   if (state_ == PAUSED) {
 135     ipc_->PlayStream();
 136     state_ = PLAYING;
 137     play_on_start_ = false;
 138   } else {
 139     play_on_start_ = true;
 140   }
 141 }
 142
 143 void AudioOutputDevice::PauseOnIOThread() {
 144   DCHECK(message_loop()->BelongsToCurrentThread());
 145   if (state_ == PLAYING) {
 146     ipc_->PauseStream();
 147     state_ = PAUSED;
 148   }
 149   play_on_start_ = false;
 150 }
 151
 152 void AudioOutputDevice::ShutDownOnIOThread() {
 153   DCHECK(message_loop()->BelongsToCurrentThread());
 154
 155   // Close the stream, if we haven't already.
 156   if (state_ >= CREATING_STREAM) {
 157     ipc_->CloseStream();
 158     state_ = IDLE;
 159   }
 160
 161   // We can run into an issue where ShutDownOnIOThread is called right after
 162   // OnStreamCreated is called in cases where Start/Stop are called before we
 163   // get the OnStreamCreated callback.  To handle that corner case, we call
 164   // Stop(). In most cases, the thread will already be stopped.
 165   //
 166   // Another situation is when the IO thread goes away before Stop() is called
 167   // in which case, we cannot use the message loop to close the thread handle
 168   // and can't rely on the main thread existing either.
 169   base::AutoLock auto_lock_(audio_thread_lock_);
 170   base::ThreadRestrictions::ScopedAllowIO allow_io;
 171   audio_thread_.Stop(NULL);
 172   audio_callback_.reset();
 173   stopping_hack_ = false;
 174 }
 175
 176 void AudioOutputDevice::SetVolumeOnIOThread(double volume) {
 177   DCHECK(message_loop()->BelongsToCurrentThread());
 178   if (state_ >= CREATING_STREAM)
 179     ipc_->SetVolume(volume);
 180 }
 181
 182 void AudioOutputDevice::OnStateChanged(AudioOutputIPCDelegate::State state) {
 183   DCHECK(message_loop()->BelongsToCurrentThread());
 184
 185   // Do nothing if the stream has been closed.
 186   if (state_ < CREATING_STREAM)
 187     return;
 188
 189   // TODO(miu): Clean-up inconsistent and incomplete handling here.
 190   // http://crbug.com/180640
 191   switch (state) {
 192     case AudioOutputIPCDelegate::kPlaying:
 193     case AudioOutputIPCDelegate::kPaused:
 194       break;
 195     case AudioOutputIPCDelegate::kError:
 196       DLOG(WARNING) << "AudioOutputDevice::OnStateChanged(kError)";
 197       // Don't dereference the callback object if the audio thread
 198       // is stopped or stopping.  That could mean that the callback
 199       // object has been deleted.
 200       // TODO(tommi): Add an explicit contract for clearing the callback
 201       // object.  Possibly require calling Initialize again or provide
 202       // a callback object via Start() and clear it in Stop().
 203       if (!audio_thread_.IsStopped())
 204         callback_->OnRenderError();
 205       break;
 206     default:
 207       NOTREACHED();
 208       break;
 209   }
 210 }
 211
 212 void AudioOutputDevice::OnStreamCreated(
 213     base::SharedMemoryHandle handle,
 214     base::SyncSocket::Handle socket_handle,
 215     int length) {
 216   DCHECK(message_loop()->BelongsToCurrentThread());
 217 #if defined(OS_WIN)
 218   DCHECK(handle);
 219   DCHECK(socket_handle);
 220 #else
 221   DCHECK_GE(handle.fd, 0);
 222   DCHECK_GE(socket_handle, 0);
 223 #endif
 224   DCHECK_GT(length, 0);
 225
 226   if (state_ != CREATING_STREAM)
 227     return;
 228
 229   // We can receive OnStreamCreated() on the IO thread after the client has
 230   // called Stop() but before ShutDownOnIOThread() is processed. In such a
 231   // situation |callback_| might point to freed memory. Instead of starting
 232   // |audio_thread_| do nothing and wait for ShutDownOnIOThread() to get called.
 233   //
 234   // TODO(scherkus): The real fix is to have sane ownership semantics. The fact
 235   // that |callback_| (which should own and outlive this object!) can point to
 236   // freed memory is a mess. AudioRendererSink should be non-refcounted so that
 237   // owners (WebRtcAudioDeviceImpl, AudioRendererImpl, etc...) can Stop() and
 238   // delete as they see fit. AudioOutputDevice should internally use WeakPtr
 239   // to handle teardown and thread hopping. See http://crbug.com/151051 for
 240   // details.
 241   base::AutoLock auto_lock(audio_thread_lock_);
 242   if (stopping_hack_)
 243     return;
 244
 245   DCHECK(audio_thread_.IsStopped());
 246   audio_callback_.reset(new AudioOutputDevice::AudioThreadCallback(
 247       audio_parameters_, handle, length, callback_));
 248   audio_thread_.Start(audio_callback_.get(), socket_handle,
 249       "AudioOutputDevice");
 250   state_ = PAUSED;
 251
 252   // We handle the case where Play() and/or Pause() may have been called
 253   // multiple times before OnStreamCreated() gets called.
 254   if (play_on_start_)
 255     PlayOnIOThread();
 256 }
 257
 258 void AudioOutputDevice::OnIPCClosed() {
 259   DCHECK(message_loop()->BelongsToCurrentThread());
 260   state_ = IPC_CLOSED;
 261   ipc_.reset();
 262 }
 263
 264 void AudioOutputDevice::WillDestroyCurrentMessageLoop() {
 265   LOG(ERROR) << "IO loop going away before the audio device has been stopped";
 266   ShutDownOnIOThread();
 267 }
 268
 269 // AudioOutputDevice::AudioThreadCallback
 270
 271 AudioOutputDevice::AudioThreadCallback::AudioThreadCallback(
 272     const AudioParameters& audio_parameters,
 273     base::SharedMemoryHandle memory,
 274     int memory_length,
 275     AudioRendererSink::RenderCallback* render_callback)
 276     : AudioDeviceThread::Callback(audio_parameters,
 277                                   memory,
 278                                   memory_length,
 279                                   1),
 280       render_callback_(render_callback) {
 281 }
 282
 283 AudioOutputDevice::AudioThreadCallback::~AudioThreadCallback() {
 284 }
 285
 286 void AudioOutputDevice::AudioThreadCallback::MapSharedMemory() {
 287   CHECK_EQ(total_segments_, 1);
 288   CHECK(shared_memory_.Map(TotalSharedMemorySizeInBytes(memory_length_)));
 289
 290   // Calculate output and input memory size.
 291   int output_memory_size = AudioBus::CalculateMemorySize(audio_parameters_);
 292   int input_channels = audio_parameters_.input_channels();
 293   int frames = audio_parameters_.frames_per_buffer();
 294   int input_memory_size =
 295       AudioBus::CalculateMemorySize(input_channels, frames);
 296
 297   int io_size = output_memory_size + input_memory_size;
 298
 299   DCHECK_EQ(memory_length_, io_size);
 300
 301   output_bus_ =
 302       AudioBus::WrapMemory(audio_parameters_, shared_memory_.memory());
 303
 304   if (input_channels > 0) {
 305     // The input data is after the output data.
 306     char* input_data =
 307         static_cast<char*>(shared_memory_.memory()) + output_memory_size;
 308     input_bus_ =
 309         AudioBus::WrapMemory(input_channels, frames, input_data);
 310   }
 311 }
 312
 313 // Called whenever we receive notifications about pending data.
 314 void AudioOutputDevice::AudioThreadCallback::Process(int pending_data) {
 315   if (pending_data == kPauseMark) {
 316     memset(shared_memory_.memory(), 0, memory_length_);
 317     SetActualDataSizeInBytes(&shared_memory_, memory_length_, 0);
 318     return;
 319   }
 320
 321   // Convert the number of pending bytes in the render buffer
 322   // into milliseconds.
 323   int audio_delay_milliseconds = pending_data / bytes_per_ms_;
 324
 325   TRACE_EVENT0("audio", "AudioOutputDevice::FireRenderCallback");
 326
 327   // Update the audio-delay measurement then ask client to render audio.  Since
 328   // |output_bus_| is wrapping the shared memory the Render() call is writing
 329   // directly into the shared memory.
 330   int input_channels = audio_parameters_.input_channels();
 331   size_t num_frames = audio_parameters_.frames_per_buffer();
 332
 333   if (input_bus_.get() && input_channels > 0) {
 334     render_callback_->RenderIO(input_bus_.get(),
 335                                output_bus_.get(),
 336                                audio_delay_milliseconds);
 337   } else {
 338     num_frames = render_callback_->Render(output_bus_.get(),
 339                                           audio_delay_milliseconds);
 340   }
 341
 342   // Let the host know we are done.
 343   // TODO(dalecurtis): Technically this is not always correct.  Due to channel
 344   // padding for alignment, there may be more data available than this.  We're
 345   // relying on AudioSyncReader::Read() to parse this with that in mind.  Rename
 346   // these methods to Set/GetActualFrameCount().
 347   SetActualDataSizeInBytes(
 348       &shared_memory_, memory_length_,
 349       num_frames * sizeof(*output_bus_->channel(0)) * output_bus_->channels());
 350 }
 351
 352 }  // namespace media.