Integrate HTMLMediaElement with Web Audio API's MediaElementAudioSourceNode

webkit/media/webmediaplayer_impl.h

 // Copyright (c) 2011 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.
 
 // Delegate calls from WebCore::MediaPlayerPrivate to Chrome's video player.
 // It contains PipelineImpl which is the actual media player pipeline, it glues
 // the media player pipeline, data source, audio renderer and renderer.
 // PipelineImpl would creates multiple threads and access some public methods
 // of this class, so we need to be extra careful about concurrent access of
 // methods and members.
@@ skipping 34 matching lines @@
 // at destruction of this class we will need to unhook it from destruction event
 // list of the main thread.
 
 #ifndef WEBKIT_MEDIA_WEBMEDIAPLAYER_IMPL_H_
 #define WEBKIT_MEDIA_WEBMEDIAPLAYER_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
+#include "media/base/audio_renderer_sink.h"
 #include "media/base/filters.h"
 #include "media/base/message_loop_factory.h"
 #include "media/base/pipeline.h"
 #include "skia/ext/platform_canvas.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebAudioSourceProvider.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaPlayer.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaPlayerClient.h"
 
+class RenderAudioSourceProvider;
+
 namespace WebKit {
+class WebAudioSourceProvider;
 class WebFrame;
 }
 
 namespace media {
 class MediaLog;
 }
 
 namespace webkit_media {
 
 class MediaStreamClient;
@@ skipping 18 matching lines @@
   // 2. FFmpeg audio decoder
   // 3. FFmpeg video decoder
   // 4. Video renderer
   // 5. Null audio renderer
   // The video renderer provided by this class is using the graphics context
   // provided by WebKit to perform renderering. The simple data source does
   // resource loading by loading the whole resource object into memory. Null
   // audio renderer is a fake audio device that plays silence. Provider of the
   // |collection| can override the default filters by adding extra filters to
   // |collection| before calling this method.
+  // This object takes ownership of the |audio_source_provider|.

[Ami GONE FROM CHROMIUM, 2012/01/13 18:02:15]

This comment is a lie in patchset 11 (and what ended up landing), because
audio_source_provider_ is a raw pointer.
I *think* the truth is that AudioRendererImpl (which receives a copy of
audio_source_provider in RenderViewImpl::createMediaPlayer) is responsible for
deleting the audio_source_provider by holding a scoped_refptr<> to it.

If that's true, please remove the comment here.
If I'm misreading the other code can you clarify?

Thanks!

   //
   // Callers must call |Initialize()| before they can use the object.
   WebMediaPlayerImpl(WebKit::WebMediaPlayerClient* client,
                      base::WeakPtr<WebMediaPlayerDelegate> delegate,
                      media::FilterCollection* collection,
+                     WebKit::WebAudioSourceProvider* audio_source_provider,
                      media::MessageLoopFactory* message_loop_factory,
                      MediaStreamClient* media_stream_client,
                      media::MediaLog* media_log);
   virtual ~WebMediaPlayerImpl();
 
   // Finalizes initialization of the object.
   bool Initialize(WebKit::WebFrame* frame, bool use_simple_data_source);
 
   virtual void load(const WebKit::WebURL& url);
   virtual void cancelLoad();
@@ skipping 49 matching lines @@
   virtual float mediaTimeForTimeValue(float timeValue) const;
 
   virtual unsigned decodedFrameCount() const;
   virtual unsigned droppedFrameCount() const;
   virtual unsigned audioDecodedByteCount() const;
   virtual unsigned videoDecodedByteCount() const;
 
   virtual WebKit::WebVideoFrame* getCurrentFrame();
   virtual void putCurrentFrame(WebKit::WebVideoFrame* web_video_frame);
 
+  virtual WebKit::WebAudioSourceProvider* audioSourceProvider();
+
   virtual bool sourceAppend(const unsigned char* data, unsigned length);
   virtual void sourceEndOfStream(EndOfStreamStatus status);
 
   // As we are closing the tab or even the browser, |main_loop_| is destroyed
   // even before this object gets destructed, so we need to know when
   // |main_loop_| is being destroyed and we can stop posting repaint task
   // to it.
   virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
 
   void Repaint();
@@ skipping 73 matching lines @@
 #if WEBKIT_USING_CG
   scoped_ptr<skia::PlatformCanvas> skia_canvas_;
 #endif
 
   scoped_refptr<media::MediaLog> media_log_;
 
   bool is_accelerated_compositing_active_;
 
   bool incremented_externally_allocated_memory_;
 
+  WebKit::WebAudioSourceProvider* audio_source_provider_;
+
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };
 
 }  // namespace webkit_media
 
 #endif  // WEBKIT_MEDIA_WEBMEDIAPLAYER_IMPL_H_