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