Effects Pepper Plugin and MediaStream Glue.

content/renderer/media/video_destination_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_destination_handler.h"
+
+#include <string>
+
+#include "base/logging.h"
+#include "content/renderer/media/media_stream_dependency_factory.h"
+#include "content/renderer/media/media_stream_registry_interface.h"
+#include "content/renderer/render_thread_impl.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebMediaStreamTrack.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaStreamRegistry.h"
+#include "webkit/plugins/ppapi/ppb_image_data_impl.h"
+
+using cricket::CaptureState;
+using cricket::VideoFormat;
+using webkit::ppapi::PPB_ImageData_Impl;
+using webrtc::VideoTrackInterface;
+using webrtc::VideoTrackVector;
+
+static const cricket::FourCC kEffectColorFormat = cricket::FOURCC_BGRA;
+
+namespace content {
+
+PpFrameWriter::PpFrameWriter()
+    : started_(false) {}
+
+PpFrameWriter::~PpFrameWriter() {}
+
+CaptureState PpFrameWriter::Start(const VideoFormat& capture_format) {
+  base::AutoLock auto_lock(lock_);
+  if (started_) {
+    LOG(ERROR) << "PpFrameWriter::Start - "
+               << "Got a StartCapture when already started!";
+    return cricket::CS_FAILED;
+  }
+  started_ = true;
+  return cricket::CS_STARTING;
+}
+
+void PpFrameWriter::Stop() {
+  base::AutoLock auto_lock(lock_);
+  started_ = false;
+  SignalStateChange(this, cricket::CS_STOPPED);
+}
+
+bool PpFrameWriter::IsRunning() {
+  return started_;
+}
+
+bool PpFrameWriter::GetPreferredFourccs(std::vector<uint32>* fourccs) {
+  if (!fourccs) {
+    LOG(ERROR) << "PpFrameWriter::GetPreferredFourccs - "
+               << "fourccs is NULL.";
+    return false;
+  }
+  // The effects plugin output BGRA.
+  fourccs->push_back(kEffectColorFormat);
+  return true;
+}
+
+bool PpFrameWriter::GetBestCaptureFormat(const VideoFormat& desired,
+                                         VideoFormat* best_format) {
+  if (!best_format) {
+    LOG(ERROR) << "PpFrameWriter::GetBestCaptureFormat - "
+               << "best_format is NULL.";
+    return false;
+  }
+
+  // Use the desired format as the best format.
+  best_format->width = desired.width;
+  best_format->height = desired.height;
+  best_format->fourcc = kEffectColorFormat;
+  best_format->interval = desired.interval;
+  return true;
+}
+
+bool PpFrameWriter::IsScreencast() const {
+  return false;
+}
+
+void PpFrameWriter::PutFrame(PPB_ImageData_Impl* image_data,
+                             int64 time_stamp_ns) {
+  base::AutoLock auto_lock(lock_);
+  // This assumes the handler of the SignalFrameCaptured won't call Start/Stop.
+  // TODO(ronghuawu): Avoid the using of lock. One way is to post this call to
+  // libjingle worker thread, which will require an extra copy of |image_data|.
+  // However if pepper host can hand over the ownership of |image_data|
+  // then we can avoid this extra copy.
+  if (!started_) {
+    LOG(ERROR) << "PpFrameWriter::PutFrame - "
+               << "Called when capturer is not started.";
+    return;
+  }
+  ASSERT(image_data != NULL);
+  webkit::ppapi::ImageDataAutoMapper mapper(image_data);
+  if (!mapper.is_valid()) {
+    LOG(ERROR) << "PpFrameWriter::PutFrame - "
+               << "The image could not be mapped and is unusable.";
+    return;
+  }
+  const SkBitmap* bitmap = image_data->GetMappedBitmap();
+  ASSERT(bitmap != NULL);
+
+  cricket::CapturedFrame frame;
+  frame.elapsed_time = 0;
+  frame.time_stamp = time_stamp_ns;
+  frame.pixel_height = 1;
+  frame.pixel_width = 1;
+  frame.width = bitmap->width();
+  frame.height = bitmap->height();
+  if (image_data->format() == PP_IMAGEDATAFORMAT_BGRA_PREMUL) {
+    frame.fourcc = cricket::FOURCC_BGRA;
+  } else {
+    LOG(ERROR) << "PpFrameWriter::PutFrame - Got RGBA which is not supported.";
+    ASSERT(false);
+    return;
+  }
+  frame.data_size = bitmap->getSize();
+  frame.data = bitmap->getPixels();
+
+  // This signals to libJingle that a new VideoFrame is available.
+  // libJingle have no assumptions on what thread this signal come from.
+  SignalFrameCaptured(this, &frame);
+}
+
+// PpFrameWriterProxy is a helper class to make sure the user won't use
+// PpFrameWriter after it is released (IOW its owner - WebMediaStreamTrack -
+// is released).
+class PpFrameWriterProxy : public FrameWriterInterface {
+ public:
+  PpFrameWriterProxy(VideoTrackInterface* track,
+                     PpFrameWriter* writer)
+      : track_(track),
+        writer_(writer) {
+    ASSERT(writer_ != NULL);
+  }
+
+  virtual ~PpFrameWriterProxy() {}
+
+  virtual void PutFrame(webkit::ppapi::PPB_ImageData_Impl* image_data,
+                        int64 time_stamp_ns) OVERRIDE {
+    writer_->PutFrame(image_data, time_stamp_ns);
+  }
+
+ private:
+  scoped_refptr<VideoTrackInterface> track_;
+  PpFrameWriter* writer_;
+
+  DISALLOW_COPY_AND_ASSIGN(PpFrameWriterProxy);
+};
+
+bool VideoDestinationHandler::Open(
+    MediaStreamDependencyFactory* factory,
+    MediaStreamRegistryInterface* registry,
+    const std::string& url, FrameWriterInterface** frame_writer) {

[wjia(left Chromium), 2013/05/03 21:42:55]

nit: one argument per line.

[Ronghua Wu (Left Chromium), 2013/05/03 22:40:02]

Done.

+  if (!factory) {
+    LOG(ERROR) << "VideoDestinationHandler::Open - factory is NULL.";
+  }
+  WebKit::WebMediaStream stream;
+  if (registry) {
+    stream = registry->GetMediaStream(url);
+  } else {
+    stream =
+        WebKit::WebMediaStreamRegistry::lookupMediaStreamDescriptor(GURL(url));
+  }
+  if (stream.isNull() || !stream.extraData()) {
+    LOG(ERROR) << "VideoDestinationHandler::Open - invalid url: " << url;
+    return false;
+  }
+
+  // Create a new native video track and add it to |stream|.
+  std::string track_id = talk_base::ToString(talk_base::CreateRandomId64());
+  PpFrameWriter* writer = new PpFrameWriter();
+  if (!factory->AddNativeVideoMediaTrack(track_id, &stream, writer)) {
+    delete writer;
+    return false;
+  }
+
+  // Gets a handler to the native video track, which owns the |writer|.
+  MediaStreamExtraData* extra_data =
+      static_cast<MediaStreamExtraData*>(stream.extraData());
+  DCHECK(extra_data);
+  webrtc::MediaStreamInterface* native_stream = extra_data->stream();
+  DCHECK(native_stream);
+  VideoTrackVector video_tracks = native_stream->GetVideoTracks();
+  // Currently one supports one video track per media stream.
+  ASSERT(video_tracks.size() == 1);
+
+  *frame_writer = new PpFrameWriterProxy(video_tracks[0].get(), writer);
+  return true;
+}
+
+}  // namespace content
+