Refactor VideoDestinationHandler to implement MediaStreamVideoSource.

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/base64.h"
-#include "base/logging.h"
-#include "base/rand_util.h"
-#include "content/renderer/media/media_stream.h"
-#include "content/renderer/media/media_stream_dependency_factory.h"
-#include "content/renderer/media/media_stream_registry_interface.h"
-#include "content/renderer/pepper/ppb_image_data_impl.h"
-#include "content/renderer/render_thread_impl.h"
-#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
-#include "third_party/WebKit/public/platform/WebURL.h"
-#include "third_party/WebKit/public/web/WebMediaStreamRegistry.h"
-#include "url/gurl.h"
-
-using cricket::CaptureState;
-using cricket::VideoFormat;
-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;
-  }
-  if (!image_data) {
-    LOG(ERROR) << "PpFrameWriter::PutFrame - Called with NULL image_data.";
-    return;
-  }
-  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();
-  if (!bitmap) {
-    LOG(ERROR) << "PpFrameWriter::PutFrame - "
-               << "The image_data's mapped bitmap is NULL.";
-    return;
-  }
-
-  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.";
-    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) {
-    DCHECK(writer_ != NULL);
-  }
-
-  virtual ~PpFrameWriterProxy() {}
-
-  virtual void PutFrame(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) {
-  if (!factory) {
-    factory = RenderThreadImpl::current()->GetMediaStreamDependencyFactory();
-    DCHECK(factory != NULL);
-  }
-  blink::WebMediaStream stream;
-  if (registry) {
-    stream = registry->GetMediaStream(url);
-  } else {
-    stream =
-        blink::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;
-  // According to spec, a media stream track's id should be globally unique.
-  // There's no easy way to strictly achieve that. The id generated with this
-  // method should be unique for most of the cases but theoretically it's
-  // possible we can get an id that's duplicated with the existing tracks.
-  base::Base64Encode(base::RandBytesAsString(64), &track_id);
-  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|.
-  webrtc::MediaStreamInterface* native_stream = MediaStream::GetAdapter(stream);
-  DCHECK(native_stream);
-  VideoTrackVector video_tracks = native_stream->GetVideoTracks();
-  // Currently one supports one video track per media stream.
-  DCHECK(video_tracks.size() == 1);
-
-  *frame_writer = new PpFrameWriterProxy(video_tracks[0].get(), writer);
-  return true;
-}
-
-}  // namespace content
-