Effects Pepper Plugin and MediaStream Glue.

content/renderer/media/video_source_handler.cc

+// 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.
+
+#include "content/renderer/media/video_source_handler.h"
+
+#include <string>
+
+#include "base/logging.h"
+#include "content/renderer/media/media_stream_dependency_factory.h"
+#include "content/renderer/render_thread_impl.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaStreamRegistry.h"
+
+using cricket::VideoFrame;
+using cricket::VideoRenderer;
+using webrtc::VideoSourceInterface;
+
+namespace content {
+
+// PpFrameReceiver implements cricket::VideoRenderer so that it can be attached
+// to native video track's video source to receive the captured frame.
+// It can be attached to a FrameReaderInterface to output the received frame.
+class CONTENT_EXPORT PpFrameReceiver
+    : public NON_EXPORTED_BASE(cricket::VideoRenderer) {
+ public:
+  PpFrameReceiver() : reader_(NULL) {}
+  virtual ~PpFrameReceiver() {}
+
+  // Implements VideoRenderer.
+  virtual bool SetSize(int width, int height, int reserved) OVERRIDE {
+    return true;
+  }
+  virtual bool RenderFrame(const cricket::VideoFrame* frame) OVERRIDE {
+    base::AutoLock auto_lock(lock_);
+    if (reader_) {
+      // Make a shallow copy of the frame as the |reader_| may need to queue it.
+      // Both frames will share a single reference-counted frame buffer.
+      reader_->GotFrame(frame->Copy());
+    }
+    return true;
+  }
+
+  void SetReader(FrameReaderInterface* reader) {
+    base::AutoLock auto_lock(lock_);
+    reader_ = reader;
+  }
+
+ private:
+  FrameReaderInterface* reader_;
+  base::Lock lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(PpFrameReceiver);
+};
+
+VideoSourceHandler::VideoSourceHandler(
+    MediaStreamDependencyFactory* factory,
+    MediaStreamRegistryInterface* registry)
+    : factory_(factory),
+      registry_(registry) {
+  ASSERT(factory_ != NULL);
+}
+
+bool VideoSourceHandler::Open(const std::string& url,
+                              FrameReaderInterface* reader) {
+  scoped_refptr<webrtc::VideoSourceInterface> source = GetFirstVideoSource(url);
+  if (!source.get()) {
+    return false;
+  }
+  PpFrameReceiver* receiver = new PpFrameReceiver();
+  receiver->SetReader(reader);
+  source->AddSink(receiver);
+  reader_to_receiver_[reader] = receiver;
+  return true;
+}
+
+bool VideoSourceHandler::Close(const std::string& url,
+                               FrameReaderInterface* reader) {
+  scoped_refptr<webrtc::VideoSourceInterface> source = GetFirstVideoSource(url);
+  if (!source.get()) {
+    LOG(ERROR) << "VideoSourceHandler::Close - Failed to get the video source "
+               << "from MediaStream with url: " << url;
+    return false;
+  }
+  PpFrameReceiver* receiver =
+      static_cast<PpFrameReceiver*>(GetReceiver(reader));
+  receiver->SetReader(NULL);
+  source->RemoveSink(receiver);

[wjia(left Chromium), 2013/05/03 02:00:38]

should receiver be removed from reader_to_receiver_ somewhere?

[Ronghua Wu (Left Chromium), 2013/05/03 05:37:28]

It should. thanks.
Added test as well.

+  return true;
+}
+
+scoped_refptr<VideoSourceInterface> VideoSourceHandler::GetFirstVideoSource(
+    const std::string& url) {
+  scoped_refptr<webrtc::VideoSourceInterface> source;
+  WebKit::WebMediaStream stream;
+  if (registry_) {
+    stream = registry_->GetMediaStream(url);
+  } else {
+    stream =
+        WebKit::WebMediaStreamRegistry::lookupMediaStreamDescriptor(GURL(url));
+  }
+  if (stream.isNull() || !stream.extraData()) {
+    LOG(ERROR) << "GetFirstVideoSource - invalid url: " << url;
+    return source;
+  }
+
+  // Get the first video track from the stream.
+  MediaStreamExtraData* extra_data =
+      static_cast<MediaStreamExtraData*>(stream.extraData());
+  if (!extra_data) {
+    LOG(ERROR) << "GetFirstVideoSource - MediaStreamExtraData is NULL.";
+    return source;
+  }
+  webrtc::MediaStreamInterface* native_stream = extra_data->stream();
+  if (!native_stream) {
+    LOG(ERROR) << "GetFirstVideoSource - native stream is NULL.";
+    return source;
+  }
+  webrtc::VideoTrackVector native_video_tracks =
+      native_stream->GetVideoTracks();
+  if (native_video_tracks.empty()) {
+    LOG(ERROR) << "GetFirstVideoSource - stream has no video track.";
+    return source;
+  }
+  source = native_video_tracks[0]->GetSource();
+  return source;
+}
+
+VideoRenderer* VideoSourceHandler::GetReceiver(
+    FrameReaderInterface* reader) {
+  std::map<FrameReaderInterface*, VideoRenderer*>::iterator it;
+  it = reader_to_receiver_.find(reader);
+  if (it == reader_to_receiver_.end()) {
+    return NULL;
+  }
+  return it->second;
+}
+
+}  // namespace content
+