media/audio/audio_input_controller.h

   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 #ifndef MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_
   6 #define MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_
   7
   8 #include <string>
   9 #include "base/atomicops.h"
  10 #include "base/callback.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/synchronization/lock.h"
  14 #include "base/synchronization/waitable_event.h"
  15 #include "base/threading/thread.h"
  16 #include "base/timer/timer.h"
  17 #include "media/audio/audio_io.h"
  18 #include "media/audio/audio_manager_base.h"
  19 #include "media/audio/audio_parameters.h"
  20 #include "media/base/audio_bus.h"
  21
  22 // An AudioInputController controls an AudioInputStream and records data
  23 // from this input stream. The two main methods are Record() and Close() and
  24 // they are both executed on the audio thread which is injected by the two
  25 // alternative factory methods, Create() or CreateLowLatency().
  26 //
  27 // All public methods of AudioInputController are non-blocking.
  28 //
  29 // Here is a state diagram for the AudioInputController:
  30 //
  31 //                    .-->  [ Closed / Error ]  <--.
  32 //                    |                            |
  33 //                    |                            |
  34 //               [ Created ]  ---------->  [ Recording ]
  35 //                    ^
  36 //                    |
  37 //              *[  Empty  ]
  38 //
  39 // * Initial state
  40 //
  41 // State sequences (assuming low-latency):
  42 //
  43 //  [Creating Thread]                     [Audio Thread]
  44 //
  45 //      User               AudioInputController               EventHandler
  46 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  47 // CrateLowLatency() ==>        DoCreate()
  48 //                   AudioManager::MakeAudioInputStream()
  49 //                        AudioInputStream::Open()
  50 //                                  .- - - - - - - - - - - - ->   OnError()
  51 //                          create the data timer
  52 //                                  .------------------------->  OnCreated()
  53 //                               kCreated
  54 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  55 // Record() ==>                 DoRecord()
  56 //                      AudioInputStream::Start()
  57 //                                  .------------------------->  OnRecording()
  58 //                          start the data timer
  59 //                              kRecording
  60 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  61 // Close() ==>                  DoClose()
  62 //                        delete the data timer
  63 //                           state_ = kClosed
  64 //                        AudioInputStream::Stop()
  65 //                        AudioInputStream::Close()
  66 //                          SyncWriter::Close()
  67 // Closure::Run() <-----------------.
  68 // (closure-task)
  69 //
  70 // The audio thread itself is owned by the AudioManager that the
  71 // AudioInputController holds a reference to.  When performing tasks on the
  72 // audio thread, the controller must not add or release references to the
  73 // AudioManager or itself (since it in turn holds a reference to the manager).
  74 //
  75 namespace media {
  76
  77 // Only do power monitoring for non-mobile platforms to save resources.
  78 #if !defined(OS_ANDROID) && !defined(OS_IOS)
  79 #define AUDIO_POWER_MONITORING
  80 #endif
  81
  82 class UserInputMonitor;
  83
  84 class MEDIA_EXPORT AudioInputController
  85     : public base::RefCountedThreadSafe<AudioInputController>,
  86       public AudioInputStream::AudioInputCallback {
  87  public:
  88
  89   // Error codes to make native loggin more clear. These error codes are added
  90   // to generic error strings to provide a higher degree of details.
  91   // Changing these values can lead to problems when matching native debug
  92   // logs with the actual cause of error.
  93   enum ErrorCode {
  94     // An unspecified error occured.
  95     UNKNOWN_ERROR = 0,
  96
  97     // Failed to create an audio input stream.
  98     STREAM_CREATE_ERROR,  // = 1
  99
 100     // Failed to open an audio input stream.
 101     STREAM_OPEN_ERROR,  // = 2
 102
 103     // Native input stream reports an error. Exact reason differs between
 104     // platforms.
 105     STREAM_ERROR,  // = 3
 106
 107     // This can happen if a capture device has been removed or disabled.
 108     NO_DATA_ERROR,  // = 4
 109   };
 110
 111   // An event handler that receives events from the AudioInputController. The
 112   // following methods are all called on the audio thread.
 113   class MEDIA_EXPORT EventHandler {
 114    public:
 115     virtual void OnCreated(AudioInputController* controller) = 0;
 116     virtual void OnRecording(AudioInputController* controller) = 0;
 117     virtual void OnError(AudioInputController* controller,
 118                          ErrorCode error_code) = 0;
 119     virtual void OnData(AudioInputController* controller,
 120                         const AudioBus* data) = 0;
 121     virtual void OnLog(AudioInputController* controller,
 122                        const std::string& message) = 0;
 123
 124    protected:
 125     virtual ~EventHandler() {}
 126   };
 127
 128   // A synchronous writer interface used by AudioInputController for
 129   // synchronous writing.
 130   class SyncWriter {
 131    public:
 132     virtual ~SyncWriter() {}
 133
 134     // Write certain amount of data from |data|.
 135     virtual void Write(const AudioBus* data,
 136                        double volume,
 137                        bool key_pressed,
 138                        uint32 hardware_delay_bytes) = 0;
 139
 140     // Close this synchronous writer.
 141     virtual void Close() = 0;
 142   };
 143
 144   // AudioInputController::Create() can use the currently registered Factory
 145   // to create the AudioInputController. Factory is intended for testing only.
 146   // |user_input_monitor| is used for typing detection and can be NULL.
 147   class Factory {
 148    public:
 149     virtual AudioInputController* Create(
 150         AudioManager* audio_manager,
 151         EventHandler* event_handler,
 152         AudioParameters params,
 153         UserInputMonitor* user_input_monitor) = 0;
 154
 155    protected:
 156     virtual ~Factory() {}
 157   };
 158
 159   // Factory method for creating an AudioInputController.
 160   // The audio device will be created on the audio thread, and when that is
 161   // done, the event handler will receive an OnCreated() call from that same
 162   // thread. |device_id| is the unique ID of the audio device to be opened.
 163   // |user_input_monitor| is used for typing detection and can be NULL.
 164   static scoped_refptr<AudioInputController> Create(
 165       AudioManager* audio_manager,
 166       EventHandler* event_handler,
 167       const AudioParameters& params,
 168       const std::string& device_id,
 169       UserInputMonitor* user_input_monitor);
 170
 171   // Sets the factory used by the static method Create(). AudioInputController
 172   // does not take ownership of |factory|. A value of NULL results in an
 173   // AudioInputController being created directly.
 174   static void set_factory_for_testing(Factory* factory) { factory_ = factory; }
 175   AudioInputStream* stream_for_testing() { return stream_; }
 176
 177   // Factory method for creating an AudioInputController for low-latency mode.
 178   // The audio device will be created on the audio thread, and when that is
 179   // done, the event handler will receive an OnCreated() call from that same
 180   // thread. |user_input_monitor| is used for typing detection and can be NULL.
 181   static scoped_refptr<AudioInputController> CreateLowLatency(
 182       AudioManager* audio_manager,
 183       EventHandler* event_handler,
 184       const AudioParameters& params,
 185       const std::string& device_id,
 186       // External synchronous writer for audio controller.
 187       SyncWriter* sync_writer,
 188       UserInputMonitor* user_input_monitor,
 189       const bool agc_is_enabled);
 190
 191   // Factory method for creating an AudioInputController with an existing
 192   // |stream| for low-latency mode, taking ownership of |stream|. The stream
 193   // will be opened on the audio thread, and when that is done, the event
 194   // handler will receive an OnCreated() call from that same thread.
 195   // |user_input_monitor| is used for typing detection and can be NULL.
 196   static scoped_refptr<AudioInputController> CreateForStream(
 197       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
 198       EventHandler* event_handler,
 199       AudioInputStream* stream,
 200       // External synchronous writer for audio controller.
 201       SyncWriter* sync_writer,
 202       UserInputMonitor* user_input_monitor);
 203
 204   // Starts recording using the created audio input stream.
 205   // This method is called on the creator thread.
 206   virtual void Record();
 207
 208   // Closes the audio input stream. The state is changed and the resources
 209   // are freed on the audio thread. |closed_task| is then executed on the thread
 210   // that called Close().
 211   // Callbacks (EventHandler and SyncWriter) must exist until |closed_task|
 212   // is called.
 213   // It is safe to call this method more than once. Calls after the first one
 214   // will have no effect.
 215   // This method trampolines to the audio thread.
 216   virtual void Close(const base::Closure& closed_task);
 217
 218   // Sets the capture volume of the input stream. The value 0.0 corresponds
 219   // to muted and 1.0 to maximum volume.
 220   virtual void SetVolume(double volume);
 221
 222   // AudioInputCallback implementation. Threading details depends on the
 223   // device-specific implementation.
 224   void OnData(AudioInputStream* stream,
 225               const AudioBus* source,
 226               uint32 hardware_delay_bytes,
 227               double volume) override;
 228   void OnError(AudioInputStream* stream) override;
 229
 230   bool SharedMemoryAndSyncSocketMode() const { return sync_writer_ != NULL; }
 231
 232  protected:
 233   friend class base::RefCountedThreadSafe<AudioInputController>;
 234
 235   // Internal state of the source.
 236   enum State {
 237     CREATED,
 238     RECORDING,
 239     CLOSED
 240   };
 241
 242 #if defined(AUDIO_POWER_MONITORING)
 243   // Used to log a silence report (see OnData).
 244   // Elements in this enum should not be deleted or rearranged; the only
 245   // permitted operation is to add new elements before SILENCE_STATE_MAX and
 246   // update SILENCE_STATE_MAX.
 247   // Possible silence state transitions:
 248   //           SILENCE_STATE_AUDIO_AND_SILENCE
 249   //               ^                  ^
 250   // SILENCE_STATE_ONLY_AUDIO   SILENCE_STATE_ONLY_SILENCE
 251   //               ^                  ^
 252   //            SILENCE_STATE_NO_MEASUREMENT
 253   enum SilenceState {
 254     SILENCE_STATE_NO_MEASUREMENT = 0,
 255     SILENCE_STATE_ONLY_AUDIO = 1,
 256     SILENCE_STATE_ONLY_SILENCE = 2,
 257     SILENCE_STATE_AUDIO_AND_SILENCE = 3,
 258     SILENCE_STATE_MAX = SILENCE_STATE_AUDIO_AND_SILENCE
 259   };
 260 #endif
 261
 262   AudioInputController(EventHandler* handler,
 263                        SyncWriter* sync_writer,
 264                        UserInputMonitor* user_input_monitor,
 265                        const bool agc_is_enabled);
 266   ~AudioInputController() override;
 267
 268   // Methods called on the audio thread (owned by the AudioManager).
 269   void DoCreate(AudioManager* audio_manager,
 270                 const AudioParameters& params,
 271                 const std::string& device_id);
 272   void DoCreateForLowLatency(AudioManager* audio_manager,
 273                              const AudioParameters& params,
 274                              const std::string& device_id);
 275   void DoCreateForStream(AudioInputStream* stream_to_control);
 276   void DoRecord();
 277   void DoClose();
 278   void DoReportError();
 279   void DoSetVolume(double volume);
 280   void DoOnData(scoped_ptr<AudioBus> data);
 281   void DoLogAudioLevels(float level_dbfs, int microphone_volume_percent);
 282
 283   // Method to check if we get recorded data after a stream was started,
 284   // and log the result to UMA.
 285   void FirstCheckForNoData();
 286
 287   // Method which ensures that OnError() is triggered when data recording
 288   // times out. Called on the audio thread.
 289   void DoCheckForNoData();
 290
 291   // Helper method that stops, closes, and NULL:s |*stream_|.
 292   void DoStopCloseAndClearStream();
 293
 294   void SetDataIsActive(bool enabled);
 295   bool GetDataIsActive();
 296
 297 #if defined(AUDIO_POWER_MONITORING)
 298   // Updates the silence state, see enum SilenceState above for state
 299   // transitions.
 300   void UpdateSilenceState(bool silence);
 301
 302   // Logs the silence state as UMA stat.
 303   void LogSilenceState(SilenceState value);
 304 #endif
 305
 306   // Gives access to the task runner of the creating thread.
 307   scoped_refptr<base::SingleThreadTaskRunner> creator_task_runner_;
 308
 309   // The task runner of audio-manager thread that this object runs on.
 310   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 311
 312   // Contains the AudioInputController::EventHandler which receives state
 313   // notifications from this class.
 314   EventHandler* handler_;
 315
 316   // Pointer to the audio input stream object.
 317   AudioInputStream* stream_;
 318
 319   // |no_data_timer_| is used to call OnError() when we stop receiving
 320   // OnData() calls. This can occur when an audio input device is unplugged
 321   // whilst recording on Windows.
 322   // See http://crbug.com/79936 for details.
 323   // This member is only touched by the audio thread.
 324   scoped_ptr<base::Timer> no_data_timer_;
 325
 326   // This flag is used to signal that we are receiving OnData() calls, i.e,
 327   // that data is active. It can be touched by the audio thread and by the
 328   // low-level audio thread which calls OnData(). E.g. on Windows, the
 329   // low-level audio thread is called wasapi_capture_thread.
 330   base::subtle::Atomic32 data_is_active_;
 331
 332   // |state_| is written on the audio thread and is read on the hardware audio
 333   // thread. These operations need to be locked. But lock is not required for
 334   // reading on the audio input controller thread.
 335   State state_;
 336
 337   base::Lock lock_;
 338
 339   // SyncWriter is used only in low-latency mode for synchronous writing.
 340   SyncWriter* sync_writer_;
 341
 342   static Factory* factory_;
 343
 344   double max_volume_;
 345
 346   UserInputMonitor* user_input_monitor_;
 347
 348   const bool agc_is_enabled_;
 349
 350 #if defined(AUDIO_POWER_MONITORING)
 351   // Enabled in DoCrete() but not in DoCreateForStream().
 352   bool power_measurement_is_enabled_;
 353
 354   // Updated each time a power measurement is performed.
 355   base::TimeTicks last_audio_level_log_time_;
 356
 357   // Whether the silence state should sent as UMA stat.
 358   bool log_silence_state_;
 359
 360   // The silence report sent as UMA stat at the end of a session.
 361   SilenceState silence_state_;
 362 #endif
 363
 364   size_t prev_key_down_count_;
 365
 366   // Time when a low-latency stream is created.
 367   base::TimeTicks low_latency_create_time_;
 368
 369   DISALLOW_COPY_AND_ASSIGN(AudioInputController);
 370 };
 371
 372 }  // namespace media
 373
 374 #endif  // MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_