multimedia/client/webrtc_demo/third/include/media/base/video_broadcaster.h

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2.7 KiB
C++

/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef MEDIA_BASE_VIDEO_BROADCASTER_H_
#define MEDIA_BASE_VIDEO_BROADCASTER_H_
#include "api/scoped_refptr.h"
#include "api/sequence_checker.h"
#include "api/video/video_frame_buffer.h"
#include "api/video/video_source_interface.h"
#include "media/base/video_source_base.h"
#include "rtc_base/synchronization/mutex.h"
#include "rtc_base/thread_annotations.h"
namespace rtc {
// VideoBroadcaster broadcast video frames to sinks and combines VideoSinkWants
// from its sinks. It does that by implementing rtc::VideoSourceInterface and
// rtc::VideoSinkInterface. The class is threadsafe; methods may be called on
// any thread. This is needed because VideoStreamEncoder calls AddOrUpdateSink
// both on the worker thread and on the encoder task queue.
class VideoBroadcaster : public VideoSourceBase,
public VideoSinkInterface<webrtc::VideoFrame> {
public:
VideoBroadcaster();
~VideoBroadcaster() override;
void AddOrUpdateSink(VideoSinkInterface<webrtc::VideoFrame>* sink,
const VideoSinkWants& wants) override;
void RemoveSink(VideoSinkInterface<webrtc::VideoFrame>* sink) override;
// Returns true if the next frame will be delivered to at least one sink.
bool frame_wanted() const;
// Returns VideoSinkWants a source is requested to fulfill. They are
// aggregated by all VideoSinkWants from all sinks.
VideoSinkWants wants() const;
// This method ensures that if a sink sets rotation_applied == true,
// it will never receive a frame with pending rotation. Our caller
// may pass in frames without precise synchronization with changes
// to the VideoSinkWants.
void OnFrame(const webrtc::VideoFrame& frame) override;
void OnDiscardedFrame() override;
protected:
void UpdateWants() RTC_EXCLUSIVE_LOCKS_REQUIRED(sinks_and_wants_lock_);
const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& GetBlackFrameBuffer(
int width,
int height) RTC_EXCLUSIVE_LOCKS_REQUIRED(sinks_and_wants_lock_);
mutable webrtc::Mutex sinks_and_wants_lock_;
VideoSinkWants current_wants_ RTC_GUARDED_BY(sinks_and_wants_lock_);
rtc::scoped_refptr<webrtc::VideoFrameBuffer> black_frame_buffer_;
bool previous_frame_sent_to_all_sinks_ RTC_GUARDED_BY(sinks_and_wants_lock_) =
true;
};
} // namespace rtc
#endif // MEDIA_BASE_VIDEO_BROADCASTER_H_