Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : #ifndef WEBRTC_MEDIA_BASE_VIDEOBROADCASTER_H_
      12             : #define WEBRTC_MEDIA_BASE_VIDEOBROADCASTER_H_
      13             : 
      14             : #include <memory>
      15             : #include <utility>
      16             : #include <vector>
      17             : 
      18             : #include "webrtc/api/video/video_frame.h"
      19             : #include "webrtc/base/criticalsection.h"
      20             : #include "webrtc/base/thread_checker.h"
      21             : #include "webrtc/media/base/videosinkinterface.h"
      22             : #include "webrtc/media/base/videosourcebase.h"
      23             : 
      24             : namespace rtc {
      25             : 
      26             : // VideoBroadcaster broadcast video frames to sinks and combines
      27             : // VideoSinkWants from its sinks. It does that by implementing
      28             : // rtc::VideoSourceInterface and rtc::VideoSinkInterface.
      29             : // Sinks must be added and removed on one and only one thread.
      30             : // Video frames can be broadcasted on any thread. I.e VideoBroadcaster::OnFrame
      31             : // can be called on any thread.
      32           0 : class VideoBroadcaster : public VideoSourceBase,
      33             :                          public VideoSinkInterface<webrtc::VideoFrame> {
      34             :  public:
      35             :   VideoBroadcaster();
      36             :   void AddOrUpdateSink(VideoSinkInterface<webrtc::VideoFrame>* sink,
      37             :                        const VideoSinkWants& wants) override;
      38             :   void RemoveSink(VideoSinkInterface<webrtc::VideoFrame>* sink) override;
      39             : 
      40             :   // Returns true if the next frame will be delivered to at least one sink.
      41             :   bool frame_wanted() const;
      42             : 
      43             :   // Returns VideoSinkWants a source is requested to fulfill. They are
      44             :   // aggregated by all VideoSinkWants from all sinks.
      45             :   VideoSinkWants wants() const;
      46             : 
      47             :   // This method ensures that if a sink sets rotation_applied == true,
      48             :   // it will never receive a frame with pending rotation. Our caller
      49             :   // may pass in frames without precise synchronization with changes
      50             :   // to the VideoSinkWants.
      51             :   void OnFrame(const webrtc::VideoFrame& frame) override;
      52             : 
      53             :  protected:
      54             :   void UpdateWants() EXCLUSIVE_LOCKS_REQUIRED(sinks_and_wants_lock_);
      55             :   const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& GetBlackFrameBuffer(
      56             :       int width, int height)
      57             :       EXCLUSIVE_LOCKS_REQUIRED(sinks_and_wants_lock_);
      58             : 
      59             :   ThreadChecker thread_checker_;
      60             :   rtc::CriticalSection sinks_and_wants_lock_;
      61             : 
      62             :   VideoSinkWants current_wants_ GUARDED_BY(sinks_and_wants_lock_);
      63             :   rtc::scoped_refptr<webrtc::VideoFrameBuffer> black_frame_buffer_;
      64             : };
      65             : 
      66             : }  // namespace rtc
      67             : 
      68             : #endif  // WEBRTC_MEDIA_BASE_VIDEOBROADCASTER_H_