chromium/remoting/protocol/video_frame_pump.h

// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef REMOTING_PROTOCOL_VIDEO_FRAME_PUMP_H_
#define REMOTING_PROTOCOL_VIDEO_FRAME_PUMP_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <vector>

#include "base/memory/raw_ptr.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "remoting/codec/video_encoder.h"
#include "remoting/proto/video.pb.h"
#include "remoting/protocol/capture_scheduler.h"
#include "remoting/protocol/desktop_capturer.h"
#include "remoting/protocol/video_stream.h"

namespace base {
class SingleThreadTaskRunner;
}  // namespace base

namespace remoting::protocol {

class VideoFeedbackStub;
class VideoStub;

// Class responsible for scheduling frame captures from a screen capturer,
// delivering them to a VideoEncoder to encode, and finally passing the encoded
// video packets to the specified VideoStub to send on the network.
//
// THREADING
//
// This class is supplied TaskRunners to use for capture, encode and network
// operations.  Capture, encode and network transmission tasks are interleaved
// as illustrated below:
//
// |       CAPTURE       ENCODE     NETWORK
// |    .............
// |    .  Capture  .
// |    .............
// |                  ............
// |                  .          .
// |    ............. .          .
// |    .  Capture  . .  Encode  .
// |    ............. .          .
// |                  .          .
// |                  ............
// |    ............. ............ ..........
// |    .  Capture  . .          . .  Send  .
// |    ............. .          . ..........
// |                  .  Encode  .
// |                  .          .
// |                  .          .
// |                  ............
// | Time
// v
//
// VideoFramePump would ideally schedule captures so as to saturate the slowest
// of the capture, encode and network processes.  However, it also needs to
// rate-limit captures to avoid overloading the host system, either by consuming
// too much CPU, or hogging the host's graphics subsystem.
class VideoFramePump : public VideoStream,
                       public webrtc::DesktopCapturer::Callback { … };

}  // namespace remoting::protocol

#endif  // REMOTING_PROTOCOL_VIDEO_FRAME_PUMP_H_