cast_video_capturer_adapter.h revision 6e8cce623b6e4fe0c9e4af605d675dd9d0338c38 
1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef REMOTING_HOST_CAST_VIDEO_CAPTURER_ADAPTER_H_
6#define REMOTING_HOST_CAST_VIDEO_CAPTURER_ADAPTER_H_
7
8#include <vector>
9
10#include "base/memory/scoped_ptr.h"
11#include "base/threading/thread_checker.h"
12#include "base/timer/timer.h"
13#include "third_party/libjingle/source/talk/media/base/videocapturer.h"
14#include "third_party/webrtc/modules/desktop_capture/screen_capturer.h"
15
16namespace base {
17class SingleThreadTaskRunner;
18}  // namespace base
19
20namespace webrtc {
21class DesktopFrame;
22}  // namespace webrtc
23
24namespace remoting {
25
26// This class controls the capture of video frames from the desktop and is used
27// to construct a VideoSource as part of the webrtc PeerConnection API.
28// CastVideoCapturerAdapter acts as an adapter between webrtc::ScreenCapturer
29// and the cricket::VideoCapturer interface, which it implements. It is used
30// to construct a cricket::VideoSource for a PeerConnection, to capture frames
31// of the desktop. As indicated in the base implementation, Start() and Stop()
32// should be called on the same thread.
33class CastVideoCapturerAdapter : public cricket::VideoCapturer,
34                                 public webrtc::DesktopCapturer::Callback {
35 public:
36  explicit CastVideoCapturerAdapter(
37      scoped_ptr<webrtc::ScreenCapturer> capturer);
38
39  virtual ~CastVideoCapturerAdapter();
40
41  // webrtc::DesktopCapturer::Callback implementation.
42  virtual webrtc::SharedMemory* CreateSharedMemory(size_t size) OVERRIDE;
43  // Converts |frame| to a cricket::CapturedFrame and emits that via
44  // SignalFrameCaptured for the base::VideoCapturer implementation to process.
45  virtual void OnCaptureCompleted(webrtc::DesktopFrame* frame) OVERRIDE;
46
47  // cricket::VideoCapturer implementation.
48  virtual bool GetBestCaptureFormat(const cricket::VideoFormat& desired,
49                                  cricket::VideoFormat* best_format) OVERRIDE;
50  virtual cricket::CaptureState Start(
51      const cricket::VideoFormat& capture_format) OVERRIDE;
52  virtual bool Pause(bool pause) OVERRIDE;
53  virtual void Stop() OVERRIDE;
54  virtual bool IsRunning() OVERRIDE;
55  virtual bool IsScreencast() const OVERRIDE;
56  virtual bool GetPreferredFourccs(std::vector<uint32>* fourccs) OVERRIDE;
57
58 private:
59  // Kicks off the next frame capture using |screen_capturer_|.
60  // The captured frame will be passed to OnCaptureCompleted().
61  void CaptureNextFrame();
62
63  // |thread_checker_| is bound to the peer connection worker thread.
64  base::ThreadChecker thread_checker_;
65
66  // Used to capture frames.
67  scoped_ptr<webrtc::ScreenCapturer> screen_capturer_;
68
69  // Used to schedule periodic screen captures.
70  scoped_ptr<base::RepeatingTimer<CastVideoCapturerAdapter> > capture_timer_;
71
72  // Used to set the elapsed_time attribute of captured frames.
73  base::TimeTicks start_time_;
74
75  DISALLOW_COPY_AND_ASSIGN(CastVideoCapturerAdapter);
76};
77
78}  // namespace remoting
79
80#endif  // REMOTING_HOST_CAST_VIDEO_CAPTURER_ADAPTER_H_
81
82