content/renderer/media/webrtc/webrtc_video_capturer_adapter.h

   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 CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_CAPTURER_ADAPTER_H_
   6 #define CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_CAPTURER_ADAPTER_H_
   7
   8 #include <vector>
   9
  10 #include "base/compiler_specific.h"
  11 #include "base/message_loop/message_loop_proxy.h"
  12 #include "base/threading/thread_checker.h"
  13 #include "content/common/content_export.h"
  14 #include "media/base/video_capture_types.h"
  15 #include "media/base/video_frame.h"
  16 #include "third_party/libjingle/source/talk/media/base/videocapturer.h"
  17
  18 namespace content {
  19
  20 // WebRtcVideoCapturerAdapter implements a simple cricket::VideoCapturer that is
  21 // used for VideoCapturing in libJingle and especially in PeerConnections.
  22 // The class is created and destroyed on the main render thread.
  23 // PeerConnection access cricket::VideoCapturer from a libJingle worker thread.
  24 // An instance of WebRtcVideoCapturerAdapter is owned by an instance of
  25 // webrtc::VideoSourceInterface in libJingle. The implementation of
  26 // webrtc::VideoSourceInterface guarantees that this object is not deleted
  27 // while it is still used in libJingle.
  28 class CONTENT_EXPORT WebRtcVideoCapturerAdapter
  29     : NON_EXPORTED_BASE(public cricket::VideoCapturer) {
  30  public:
  31   explicit WebRtcVideoCapturerAdapter(bool is_screencast);
  32   ~WebRtcVideoCapturerAdapter() override;
  33
  34   // OnFrameCaptured delivers video frames to libjingle. It must be called on
  35   // libjingles worker thread.
  36   // This method is virtual for testing purposes.
  37   virtual void OnFrameCaptured(const scoped_refptr<media::VideoFrame>& frame);
  38
  39  private:
  40   // cricket::VideoCapturer implementation.
  41   // These methods are accessed from a libJingle worker thread.
  42   cricket::CaptureState Start(
  43       const cricket::VideoFormat& capture_format) override;
  44   void Stop() override;
  45   bool IsRunning() override;
  46   bool GetPreferredFourccs(std::vector<uint32>* fourccs) override;
  47   bool GetBestCaptureFormat(const cricket::VideoFormat& desired,
  48                             cricket::VideoFormat* best_format) override;
  49   bool IsScreencast() const override;
  50
  51   // |thread_checker_| is bound to the libjingle worker thread.
  52   base::ThreadChecker thread_checker_;
  53
  54   const bool is_screencast_;
  55   bool running_;
  56   base::TimeDelta first_frame_timestamp_;
  57
  58   // This is an alias to the frame_factory_ in the base class
  59   // cricket::VideoCapturer.
  60   class MediaVideoFrameFactory;
  61   MediaVideoFrameFactory* frame_factory_;
  62
  63   DISALLOW_COPY_AND_ASSIGN(WebRtcVideoCapturerAdapter);
  64 };
  65
  66 }  // namespace content
  67
  68 #endif  // CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_CAPTURER_ADAPTER_H_