media/audio/audio_input_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_input_device.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/bind.h"
   9 #include "base/memory/scoped_vector.h"
  10 #include "base/threading/thread_restrictions.h"
  11 #include "base/time/time.h"
  12 #include "media/audio/audio_manager_base.h"
  13 #include "media/base/audio_bus.h"
  14
  15 namespace media {
  16
  17 // The number of shared memory buffer segments indicated to browser process
  18 // in order to avoid data overwriting. This number can be any positive number,
  19 // dependent how fast the renderer process can pick up captured data from
  20 // shared memory.
  21 static const int kRequestedSharedMemoryCount = 10;
  22
  23 // Takes care of invoking the capture callback on the audio thread.
  24 // An instance of this class is created for each capture stream in
  25 // OnLowLatencyCreated().
  26 class AudioInputDevice::AudioThreadCallback
  27     : public AudioDeviceThread::Callback {
  28  public:
  29   AudioThreadCallback(const AudioParameters& audio_parameters,
  30                       base::SharedMemoryHandle memory,
  31                       int memory_length,
  32                       int total_segments,
  33                       CaptureCallback* capture_callback);
  34   ~AudioThreadCallback() override;
  35
  36   void MapSharedMemory() override;
  37
  38   // Called whenever we receive notifications about pending data.
  39   void Process(uint32 pending_data) override;
  40
  41  private:
  42   int current_segment_id_;
  43   ScopedVector<media::AudioBus> audio_buses_;
  44   CaptureCallback* capture_callback_;
  45
  46   DISALLOW_COPY_AND_ASSIGN(AudioThreadCallback);
  47 };
  48
  49 AudioInputDevice::AudioInputDevice(
  50     scoped_ptr<AudioInputIPC> ipc,
  51     const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner)
  52     : ScopedTaskRunnerObserver(io_task_runner),
  53       callback_(NULL),
  54       ipc_(ipc.Pass()),
  55       state_(IDLE),
  56       session_id_(0),
  57       agc_is_enabled_(false),
  58       stopping_hack_(false) {
  59   CHECK(ipc_);
  60
  61   // The correctness of the code depends on the relative values assigned in the
  62   // State enum.
  63   static_assert(IPC_CLOSED < IDLE, "invalid enum value assignment 0");
  64   static_assert(IDLE < CREATING_STREAM, "invalid enum value assignment 1");
  65   static_assert(CREATING_STREAM < RECORDING, "invalid enum value assignment 2");
  66 }
  67
  68 void AudioInputDevice::Initialize(const AudioParameters& params,
  69                                   CaptureCallback* callback,
  70                                   int session_id) {
  71   DCHECK(params.IsValid());
  72   DCHECK(!callback_);
  73   DCHECK_EQ(0, session_id_);
  74   audio_parameters_ = params;
  75   callback_ = callback;
  76   session_id_ = session_id;
  77 }
  78
  79 void AudioInputDevice::Start() {
  80   DCHECK(callback_) << "Initialize hasn't been called";
  81   DVLOG(1) << "Start()";
  82   task_runner()->PostTask(FROM_HERE,
  83       base::Bind(&AudioInputDevice::StartUpOnIOThread, this));
  84 }
  85
  86 void AudioInputDevice::Stop() {
  87   DVLOG(1) << "Stop()";
  88
  89   {
  90     base::AutoLock auto_lock(audio_thread_lock_);
  91     audio_thread_.Stop(base::MessageLoop::current());
  92     stopping_hack_ = true;
  93   }
  94
  95   task_runner()->PostTask(FROM_HERE,
  96       base::Bind(&AudioInputDevice::ShutDownOnIOThread, this));
  97 }
  98
  99 void AudioInputDevice::SetVolume(double volume) {
 100   if (volume < 0 || volume > 1.0) {
 101     DLOG(ERROR) << "Invalid volume value specified";
 102     return;
 103   }
 104
 105   task_runner()->PostTask(FROM_HERE,
 106       base::Bind(&AudioInputDevice::SetVolumeOnIOThread, this, volume));
 107 }
 108
 109 void AudioInputDevice::SetAutomaticGainControl(bool enabled) {
 110   DVLOG(1) << "SetAutomaticGainControl(enabled=" << enabled << ")";
 111   task_runner()->PostTask(FROM_HERE,
 112       base::Bind(&AudioInputDevice::SetAutomaticGainControlOnIOThread,
 113           this, enabled));
 114 }
 115
 116 void AudioInputDevice::OnStreamCreated(
 117     base::SharedMemoryHandle handle,
 118     base::SyncSocket::Handle socket_handle,
 119     int length,
 120     int total_segments) {
 121   DCHECK(task_runner()->BelongsToCurrentThread());
 122 #if defined(OS_WIN)
 123   DCHECK(handle);
 124   DCHECK(socket_handle);
 125 #else
 126   DCHECK_GE(handle.fd, 0);
 127   DCHECK_GE(socket_handle, 0);
 128 #endif
 129   DCHECK_GT(length, 0);
 130
 131   if (state_ != CREATING_STREAM)
 132     return;
 133
 134   base::AutoLock auto_lock(audio_thread_lock_);
 135   // TODO(miu): See TODO in OnStreamCreated method for AudioOutputDevice.
 136   // Interface changes need to be made; likely, after AudioInputDevice is merged
 137   // into AudioOutputDevice (http://crbug.com/179597).
 138   if (stopping_hack_)
 139     return;
 140
 141   DCHECK(audio_thread_.IsStopped());
 142   audio_callback_.reset(new AudioInputDevice::AudioThreadCallback(
 143       audio_parameters_, handle, length, total_segments, callback_));
 144   audio_thread_.Start(
 145       audio_callback_.get(), socket_handle, "AudioInputDevice", false);
 146
 147   state_ = RECORDING;
 148   ipc_->RecordStream();
 149 }
 150
 151 void AudioInputDevice::OnVolume(double volume) {
 152   NOTIMPLEMENTED();
 153 }
 154
 155 void AudioInputDevice::OnStateChanged(
 156     AudioInputIPCDelegate::State state) {
 157   DCHECK(task_runner()->BelongsToCurrentThread());
 158
 159   // Do nothing if the stream has been closed.
 160   if (state_ < CREATING_STREAM)
 161     return;
 162
 163   // TODO(miu): Clean-up inconsistent and incomplete handling here.
 164   // http://crbug.com/180640
 165   switch (state) {
 166     case AudioInputIPCDelegate::kStopped:
 167       ShutDownOnIOThread();
 168       break;
 169     case AudioInputIPCDelegate::kRecording:
 170       NOTIMPLEMENTED();
 171       break;
 172     case AudioInputIPCDelegate::kError:
 173       DLOG(WARNING) << "AudioInputDevice::OnStateChanged(kError)";
 174       // Don't dereference the callback object if the audio thread
 175       // is stopped or stopping.  That could mean that the callback
 176       // object has been deleted.
 177       // TODO(tommi): Add an explicit contract for clearing the callback
 178       // object.  Possibly require calling Initialize again or provide
 179       // a callback object via Start() and clear it in Stop().
 180       if (!audio_thread_.IsStopped())
 181         callback_->OnCaptureError();
 182       break;
 183     default:
 184       NOTREACHED();
 185       break;
 186   }
 187 }
 188
 189 void AudioInputDevice::OnIPCClosed() {
 190   DCHECK(task_runner()->BelongsToCurrentThread());
 191   state_ = IPC_CLOSED;
 192   ipc_.reset();
 193 }
 194
 195 AudioInputDevice::~AudioInputDevice() {
 196   // TODO(henrika): The current design requires that the user calls
 197   // Stop before deleting this class.
 198   DCHECK(audio_thread_.IsStopped());
 199 }
 200
 201 void AudioInputDevice::StartUpOnIOThread() {
 202   DCHECK(task_runner()->BelongsToCurrentThread());
 203
 204   // Make sure we don't call Start() more than once.
 205   if (state_ != IDLE)
 206     return;
 207
 208   if (session_id_ <= 0) {
 209     DLOG(WARNING) << "Invalid session id for the input stream " << session_id_;
 210     return;
 211   }
 212
 213   state_ = CREATING_STREAM;
 214   ipc_->CreateStream(this, session_id_, audio_parameters_,
 215                      agc_is_enabled_, kRequestedSharedMemoryCount);
 216 }
 217
 218 void AudioInputDevice::ShutDownOnIOThread() {
 219   DCHECK(task_runner()->BelongsToCurrentThread());
 220
 221   // Close the stream, if we haven't already.
 222   if (state_ >= CREATING_STREAM) {
 223     ipc_->CloseStream();
 224     state_ = IDLE;
 225     agc_is_enabled_ = false;
 226   }
 227
 228   // We can run into an issue where ShutDownOnIOThread is called right after
 229   // OnStreamCreated is called in cases where Start/Stop are called before we
 230   // get the OnStreamCreated callback.  To handle that corner case, we call
 231   // Stop(). In most cases, the thread will already be stopped.
 232   //
 233   // Another situation is when the IO thread goes away before Stop() is called
 234   // in which case, we cannot use the message loop to close the thread handle
 235   // and can't not rely on the main thread existing either.
 236   base::AutoLock auto_lock_(audio_thread_lock_);
 237   base::ThreadRestrictions::ScopedAllowIO allow_io;
 238   audio_thread_.Stop(NULL);
 239   audio_callback_.reset();
 240   stopping_hack_ = false;
 241 }
 242
 243 void AudioInputDevice::SetVolumeOnIOThread(double volume) {
 244   DCHECK(task_runner()->BelongsToCurrentThread());
 245   if (state_ >= CREATING_STREAM)
 246     ipc_->SetVolume(volume);
 247 }
 248
 249 void AudioInputDevice::SetAutomaticGainControlOnIOThread(bool enabled) {
 250   DCHECK(task_runner()->BelongsToCurrentThread());
 251
 252   if (state_ >= CREATING_STREAM) {
 253     DLOG(WARNING) << "The AGC state can not be modified after starting.";
 254     return;
 255   }
 256
 257   // We simply store the new AGC setting here. This value will be used when
 258   // a new stream is initialized and by GetAutomaticGainControl().
 259   agc_is_enabled_ = enabled;
 260 }
 261
 262 void AudioInputDevice::WillDestroyCurrentMessageLoop() {
 263   LOG(ERROR) << "IO loop going away before the input device has been stopped";
 264   ShutDownOnIOThread();
 265 }
 266
 267 // AudioInputDevice::AudioThreadCallback
 268 AudioInputDevice::AudioThreadCallback::AudioThreadCallback(
 269     const AudioParameters& audio_parameters,
 270     base::SharedMemoryHandle memory,
 271     int memory_length,
 272     int total_segments,
 273     CaptureCallback* capture_callback)
 274     : AudioDeviceThread::Callback(audio_parameters, memory, memory_length,
 275                                   total_segments),
 276       current_segment_id_(0),
 277       capture_callback_(capture_callback) {
 278 }
 279
 280 AudioInputDevice::AudioThreadCallback::~AudioThreadCallback() {
 281 }
 282
 283 void AudioInputDevice::AudioThreadCallback::MapSharedMemory() {
 284   shared_memory_.Map(memory_length_);
 285
 286   // Create vector of audio buses by wrapping existing blocks of memory.
 287   uint8* ptr = static_cast<uint8*>(shared_memory_.memory());
 288   for (int i = 0; i < total_segments_; ++i) {
 289     media::AudioInputBuffer* buffer =
 290         reinterpret_cast<media::AudioInputBuffer*>(ptr);
 291     scoped_ptr<media::AudioBus> audio_bus =
 292         media::AudioBus::WrapMemory(audio_parameters_, buffer->audio);
 293     audio_buses_.push_back(audio_bus.release());
 294     ptr += segment_length_;
 295   }
 296 }
 297
 298 void AudioInputDevice::AudioThreadCallback::Process(uint32 pending_data) {
 299   // The shared memory represents parameters, size of the data buffer and the
 300   // actual data buffer containing audio data. Map the memory into this
 301   // structure and parse out parameters and the data area.
 302   uint8* ptr = static_cast<uint8*>(shared_memory_.memory());
 303   ptr += current_segment_id_ * segment_length_;
 304   AudioInputBuffer* buffer = reinterpret_cast<AudioInputBuffer*>(ptr);
 305   // Usually this will be equal but in the case of low sample rate (e.g. 8kHz,
 306   // the buffer may be bigger (on mac at least)).
 307   DCHECK_GE(buffer->params.size,
 308             segment_length_ - sizeof(AudioInputBufferParameters));
 309   double volume = buffer->params.volume;
 310   bool key_pressed = buffer->params.key_pressed;
 311
 312   // Use pre-allocated audio bus wrapping existing block of shared memory.
 313   media::AudioBus* audio_bus = audio_buses_[current_segment_id_];
 314
 315   // Deliver captured data to the client in floating point format
 316   // and update the audio-delay measurement.
 317   int audio_delay_milliseconds = pending_data / bytes_per_ms_;
 318   capture_callback_->Capture(
 319       audio_bus, audio_delay_milliseconds, volume, key_pressed);
 320
 321   if (++current_segment_id_ >= total_segments_)
 322     current_segment_id_ = 0;
 323 }
 324
 325 }  // namespace media