Interface with webrtc through encoded frames

remoting/protocol/webrtc_video_capturer_adapter.h

-// Copyright 2015 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 REMOTING_PROTOCOL_WEBRTC_VIDEO_CAPTURER_ADAPTER_H_
-#define REMOTING_PROTOCOL_WEBRTC_VIDEO_CAPTURER_ADAPTER_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <memory>
-#include <vector>
-
-#include "base/macros.h"
-#include "base/memory/weak_ptr.h"
-#include "base/threading/thread_checker.h"
-#include "base/timer/timer.h"
-#include "remoting/protocol/video_stream.h"
-#include "third_party/webrtc/media/base/videocapturer.h"
-#include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
-#include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
-
-namespace base {
-class SingleThreadTaskRunner;
-}  // namespace base
-
-namespace cricket {
-class VideoFrame;
-}  // namespace cricket
-
-namespace webrtc {
-class DesktopFrame;
-}  // namespace webrtc
-
-namespace remoting {
-namespace protocol {
-
-// This class controls the capture of video frames from the desktop and is used
-// to construct a VideoSource as part of the webrtc PeerConnection API.
-// WebrtcVideoCapturerAdapter acts as an adapter between webrtc::DesktopCapturer
-// and the cricket::VideoCapturer interface, which it implements. It is used
-// to construct a cricket::VideoSource for a PeerConnection, to capture frames
-// of the desktop. As indicated in the base implementation, Start() and Stop()
-// should be called on the same thread.
-class WebrtcVideoCapturerAdapter : public cricket::VideoCapturer,
-                                   public webrtc::DesktopCapturer::Callback {
- public:
-  explicit WebrtcVideoCapturerAdapter(
-      std::unique_ptr<webrtc::DesktopCapturer> capturer);
-  ~WebrtcVideoCapturerAdapter() override;
-
-  void SetSizeCallback(const VideoStream::SizeCallback& size_callback);
-  bool PauseCapturer(bool pause);
-  base::WeakPtr<WebrtcVideoCapturerAdapter> GetWeakPtr();
-
-  // cricket::VideoCapturer implementation.
-  bool GetBestCaptureFormat(const cricket::VideoFormat& desired,
-                            cricket::VideoFormat* best_format) override;
-  cricket::CaptureState Start(
-      const cricket::VideoFormat& capture_format) override;
-  void Stop() override;
-  bool IsRunning() override;
-  bool IsScreencast() const override;
-  bool GetPreferredFourccs(std::vector<uint32_t>* fourccs) override;
-
- private:
-  // webrtc::DesktopCapturer::Callback implementation.
-  webrtc::SharedMemory* CreateSharedMemory(size_t size) override;
-  void OnCaptureCompleted(webrtc::DesktopFrame* frame) override;
-
-  // Kicks off the next frame capture using |desktop_capturer_|. The captured
-  // frame will be passed to OnCaptureCompleted().
-  void CaptureNextFrame();
-
-  base::ThreadChecker thread_checker_;
-
-  std::unique_ptr<webrtc::DesktopCapturer> desktop_capturer_;
-
-  VideoStream::SizeCallback size_callback_;
-
-  // Timer to call CaptureNextFrame().
-  std::unique_ptr<base::RepeatingTimer> capture_timer_;
-
-  webrtc::DesktopSize frame_size_;
-  webrtc::DesktopVector frame_dpi_;
-
-  // Video frame is kept between captures to avoid YUV conversion for static
-  // parts of the screen.
-  rtc::scoped_refptr<webrtc::I420Buffer> yuv_frame_;
-
-  bool capture_pending_ = false;
-  bool paused_ = false;
-
-  base::WeakPtrFactory<WebrtcVideoCapturerAdapter> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(WebrtcVideoCapturerAdapter);
-};
-
-}  // namespace protocol
-}  // namespace remoting
-
-#endif  // REMOTING_PROTOCOL_WEBRTC_VIDEO_CAPTURER_ADAPTER_H_