Implement WebRTC in Chrome for TV

content/renderer/media/rtc_video_decoder_bridge_tv.h

+// Copyright (c) 2013 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.
+
+#ifndef CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_BRIDGE_TV_H_
+#define CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_BRIDGE_TV_H_
+
+#include "base/basictypes.h"
+#include "base/message_loop_proxy.h"
+#include "content/common/content_export.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/decoder_buffer_queue.h"
+#include "media/base/demuxer.h"
+#include "media/base/demuxer_stream.h"
+#include "media/base/pipeline_status.h"
+#include "media/base/video_decoder_config.h"
+#include "third_party/webrtc/modules/video_coding/codecs/interface/video_codec_interface.h"
+
+namespace content {
+
+class MediaStreamDependencyFactory;
+
+// A singleton object shared between WebMediaPlayerAndroid and WebRTC Video
+// Engine. Note that this class provides the first remote stream.
+//
+// Example use case:
+//
+// MediaStreamDependencyFactory* tag = ...;
+//
+// // Before using the object:
+// if (!RTCVideoDecoderBridgeTv::Get()->AcquireOwnership(tag))
+//   return;
+//
+// media::Demuxer* demuxer = RTCVideoDecoderBridgeTv::Get()->CreateDemuxer(
+//     tag, base::MessageLoopProxy::current());
+// if (demuxer) {
+//   // use |demuxer|.
+// }
+//
+// // When done using the object:
+// // NOTE: the order is not significant.
+// RTCVideoDecoderBridgeTv::Get()->DestroyDemuxer(demuxer);
+// RTCVideoDecoderBridgeTv::Get()->ReleaseOwnership(tag);
+class CONTENT_EXPORT RTCVideoDecoderBridgeTv
+    : NON_EXPORTED_BASE(public webrtc::VideoDecoder) {
+ public:
+  // Get RTCVideoDecoderBridgeTv singleton object. If it was not set
+  // before, new default instance will be created.
+  static RTCVideoDecoderBridgeTv* Get();
+
+  // Returns a demuxer object if this is not owned or owned by the same
+  // media_stream_dependency_factory.
+  virtual media::Demuxer* CreateDemuxer(
+      const MediaStreamDependencyFactory* media_stream_dependency_factory,
+      const scoped_refptr<base::MessageLoopProxy>& message_loop) = 0;

[Ami GONE FROM CHROMIUM, 2013/05/08 20:26:44]

What is |message_loop|?  is it for callback dispatch, or what?
I believe all callsites just use MessageLoopProxy::current(), in which case it's
silly to pass this explicitly through so many layers, and instead should be
replaced by doco that explains the guarantee that callbacks get fired on the
calling thread (for whichever class/method actually cares).

[wonsik, 2013/05/13 14:03:48]

N/A after refactoring

+
+  // Destroys the demuxer, owned by this object.
+  virtual void DestroyDemuxer(const media::Demuxer* demuxer) = 0;
+
+  // Returns true if acquired the ownership of this object successfully. One
+  // should acquire ownership before using the object, and can't use the object
+  // if this method fails.
+  virtual bool AcquireOwnership(
+      const MediaStreamDependencyFactory* media_stream_dependency_factory) = 0;
+
+  // Releases ownership of this object.
+  virtual void ReleaseOwnership(
+      const MediaStreamDependencyFactory* media_stream_dependency_factory) = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_BRIDGE_TV_H_