Effects Pepper Plugin and MediaStream Glue.

content/renderer/media/video_destination_handler.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_VIDEO_DESTINATION_HANDLER_H_
+#define CONTENT_RENDERER_MEDIA_VIDEO_DESTINATION_HANDLER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "content/common/content_export.h"
+#include "third_party/libjingle/source/talk/media/base/videocapturer.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebMediaStream.h"
+
+namespace content {
+
+class MediaStreamDependencyFactory;
+class MediaStreamRegistryInterface;
+
+// Interface used by the effects pepper plugin to output the processed frame
+// to the video track.
+class CONTENT_EXPORT FrameWriterInterface {
+ public:
+  // The ownership of the |frame| deosn't transfer. So the implementation of
+  // this interface should make a copy of the |frame| before return.
+  virtual void PutFrame(cricket::CapturedFrame* frame) = 0;
+
+ protected:
+  virtual ~FrameWriterInterface() {}
+};
+
+// PpFrameWriter implements cricket::VideoCapturer so that it can be used in
+// the native video track's video source. It also implements
+// FrameWriterInterface, which will be used by the effects pepper plugin to
+// inject the processed frame.
+class CONTENT_EXPORT PpFrameWriter
+    : public NON_EXPORTED_BASE(cricket::VideoCapturer),
+      public FrameWriterInterface {
+ public:
+  PpFrameWriter();
+  virtual ~PpFrameWriter();
+
+  // cricket::VideoCapturer implementation.
+  // These methods are accessed from a libJingle worker thread.
+  virtual cricket::CaptureState Start(
+      const cricket::VideoFormat& capture_format) OVERRIDE;
+  virtual void Stop() OVERRIDE;
+  virtual bool IsRunning() OVERRIDE;
+  virtual bool GetPreferredFourccs(std::vector<uint32>* fourccs) OVERRIDE;
+  virtual bool GetBestCaptureFormat(const cricket::VideoFormat& desired,
+                                    cricket::VideoFormat* best_format) OVERRIDE;
+  virtual bool IsScreencast() const OVERRIDE;
+
+  // FrameWriterInterface implementation.
+  virtual void PutFrame(cricket::CapturedFrame* frame) OVERRIDE;
+
+ private:
+  bool started_;
+};
+
+// VideoDestinationHandler is a glue class between the webrtc MediaStream and
+// the effects pepper plugin host.
+class CONTENT_EXPORT VideoDestinationHandler {
+ public:
+  VideoDestinationHandler(MediaStreamDependencyFactory* factory,
+                          MediaStreamRegistryInterface* registry);
+  bool Open(const std::string& url, FrameWriterInterface** frame_writer);

[wjia(left Chromium), 2013/04/30 18:32:11]

Please add detailed comments for API functions.

[Ronghua Wu (Left Chromium), 2013/04/30 22:42:17]

Done.

+  virtual ~VideoDestinationHandler();
+
+ private:
+  MediaStreamDependencyFactory* factory_;
+  MediaStreamRegistryInterface* registry_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_VIDEO_DESTINATION_HANDLER_H_
+