Integrate HTMLMediaElement with Web Audio API's MediaElementAudioSourceNode

content/renderer/media/audio_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.
 //
 // Low-latency audio rendering unit utilizing audio output stream provided
 // by browser process through IPC.
 //
 // Relationship of classes.
 //
 //  AudioOutputController                AudioDevice
@@ skipping 55 matching lines @@
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/shared_memory.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/simple_thread.h"
 #include "content/common/content_export.h"
 #include "content/renderer/media/audio_message_filter.h"
 #include "media/audio/audio_parameters.h"
+#include "media/base/audio_renderer_sink.h"
 
 class CONTENT_EXPORT AudioDevice
-    : public AudioMessageFilter::Delegate,
-      public base::DelegateSimpleThread::Delegate,
-      public base::RefCountedThreadSafe<AudioDevice> {
+    : public media::AudioRendererSink,
+      public AudioMessageFilter::Delegate,
+      public base::DelegateSimpleThread::Delegate {
  public:
-  class CONTENT_EXPORT RenderCallback {
-   public:
-    // Fills entire buffer of length |number_of_frames| but returns actual
-    // number of frames it got from its source (|number_of_frames| in case of
-    // continuous stream). That actual number of frames is passed to host
-    // together with PCM audio data and host is free to use or ignore it.
-    virtual size_t Render(const std::vector<float*>& audio_data,
-                          size_t number_of_frames,
-                          size_t audio_delay_milliseconds) = 0;
-   protected:
-    virtual ~RenderCallback() {}
-  };
-
   // Methods called on main render thread -------------------------------------
 
   // Minimal constructor where Initialize() must be called later.
   AudioDevice();
 
   AudioDevice(size_t buffer_size,
               int channels,
               double sample_rate,
               RenderCallback* callback);
   virtual ~AudioDevice();
 
-  void Initialize(size_t buffer_size,
-                  int channels,
-                  double sample_rate,
-                  AudioParameters::Format latency_format,
-                  RenderCallback* callback);
-  bool IsInitialized();
+  // AudioRendererSink implementation.
 
+  virtual void Initialize(size_t buffer_size,
+                          int channels,
+                          double sample_rate,
+                          AudioParameters::Format latency_format,
+                          RenderCallback* callback) OVERRIDE;
   // Starts audio playback.
-  void Start();
+  virtual void Start() OVERRIDE;
 
   // Stops audio playback.
-  void Stop();
+  virtual void Stop() OVERRIDE;
 
   // Resumes playback if currently paused.
   // TODO(crogers): it should be possible to remove the extra complexity
   // of Play() and Pause() with additional re-factoring work in
   // AudioRendererImpl.
-  void Play();
+  virtual void Play() OVERRIDE;
 
   // Pauses playback.
   // If |flush| is true then any pending audio that is in the pipeline
   // (has not yet reached the hardware) will be discarded.  In this case,
   // when Play() is later called, no previous pending audio will be
   // rendered.
-  void Pause(bool flush);
+  virtual void Pause(bool flush) OVERRIDE;
 
   // Sets the playback volume, with range [0.0, 1.0] inclusive.
   // Returns |true| on success.
-  bool SetVolume(double volume);
+  virtual bool SetVolume(double volume) OVERRIDE;
 
   // Gets the playback volume, with range [0.0, 1.0] inclusive.
-  void GetVolume(double* volume);
+  virtual void GetVolume(double* volume) OVERRIDE;
 
   double sample_rate() const { return sample_rate_; }
   size_t buffer_size() const { return buffer_size_; }
 
   // Methods called on IO thread ----------------------------------------------
   // AudioMessageFilter::Delegate methods, called by AudioMessageFilter.
   virtual void OnRequestPacket(AudioBuffersState buffers_state) OVERRIDE;
   virtual void OnStateChanged(AudioStreamState state) OVERRIDE;
   virtual void OnCreated(base::SharedMemoryHandle handle,
                          uint32 length) OVERRIDE;
@@ skipping 104 matching lines @@
 
   // Protects lifetime of:
   // audio_socket_
   // audio_thread_
   base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDevice);
 };
 
 #endif  // CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_H_