Reland 15721002: Hook up the device selection to the WebAudio live audio

media/audio/audio_output_device.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Audio rendering unit utilizing audio output stream provided by browser
 // process through IPC.
 //
 // Relationship of classes.
 //
 //  AudioOutputController                AudioOutputDevice
@@ skipping 63 matching lines @@
 
 class MEDIA_EXPORT AudioOutputDevice
     : NON_EXPORTED_BASE(public AudioRendererSink),
       NON_EXPORTED_BASE(public AudioOutputIPCDelegate),
       NON_EXPORTED_BASE(public ScopedLoopObserver) {
  public:
   // NOTE: Clients must call Initialize() before using.
   AudioOutputDevice(scoped_ptr<AudioOutputIPC> ipc,
                     const scoped_refptr<base::MessageLoopProxy>& io_loop);
 
+  // Initialize function for clients wishing to have unified input and
+  // output, |params| may specify |input_channels| > 0, representing a
+  // number of input channels which will be at the same sample-rate
+  // and buffer-size as the output as specified in |params|. |session_id| is
+  // used for the browser to select the correct input device.
+  // In this case, the callback's RenderIO() method will be called instead
+  // of Render(), providing the synchronized input data at the same time as
+  // when new output data is to be rendered.
+  void InitializeUnifiedStream(const AudioParameters& params,
+                               RenderCallback* callback,
+                               int session_id);
+
   // AudioRendererSink implementation.
   virtual void Initialize(const AudioParameters& params,
                           RenderCallback* callback) OVERRIDE;
   virtual void Start() OVERRIDE;
   virtual void Stop() OVERRIDE;
   virtual void Play() OVERRIDE;
   virtual void Pause() OVERRIDE;
   virtual bool SetVolume(double volume) OVERRIDE;
 
   // Methods called on IO thread ----------------------------------------------
@@ skipping 43 matching lines @@
   // be accessed on the IO thread.
   scoped_ptr<AudioOutputIPC> ipc_;
 
   // Current state (must only be accessed from the IO thread).  See comments for
   // State enum above.
   State state_;
 
   // State of Play() / Pause() calls before OnStreamCreated() is called.
   bool play_on_start_;
 
+  // The media session ID used to identify which input device to be started.
+  // Only used by Unified IO.
+  int session_id_;
+
   // Our audio thread callback class.  See source file for details.
   class AudioThreadCallback;
 
   // In order to avoid a race between OnStreamCreated and Stop(), we use this
   // guard to control stopping and starting the audio thread.
   base::Lock audio_thread_lock_;
   AudioDeviceThread audio_thread_;
   scoped_ptr<AudioOutputDevice::AudioThreadCallback> audio_callback_;
 
   // Temporary hack to ignore OnStreamCreated() due to the user calling Stop()
   // so we don't start the audio thread pointing to a potentially freed
   // |callback_|.
   //
   // TODO(scherkus): Replace this by changing AudioRendererSink to either accept
   // the callback via Start(). See http://crbug.com/151051 for details.
   bool stopping_hack_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioOutputDevice);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_DEVICE_H_