Interface with webrtc through encoded frames

remoting/protocol/webrtc_frame_scheduler.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_PROTOCOL_WEBRTC_FRAME_SCHEDULER_H_
+#define REMOTING_PROTOCOL_WEBRTC_FRAME_SCHEDULER_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "base/task/cancelable_task_tracker.h"
+#include "base/threading/thread_checker.h"
+#include "base/timer/timer.h"
+#include "remoting/codec/video_encoder.h"
+#include "remoting/protocol/video_stream.h"
+#include "remoting/protocol/webrtc_transport.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
+
+namespace remoting {
+namespace protocol {
+
+// Class responsible for scheduling frames for encode and hand-over to
+// WebRtc transport for sending across the network.
+class WebRtcFrameScheduler : public webrtc::DesktopCapturer::Callback {
+ public:
+  WebRtcFrameScheduler(
+      scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner,
+      std::unique_ptr<webrtc::DesktopCapturer> capturer,
+      WebrtcTransport* webrtc_transport,
+      std::unique_ptr<VideoEncoder> encoder);
+  ~WebRtcFrameScheduler() override;
+
+  // Starts scheduling frames to be encoded and transported.
+  void Start();
+  // Stops scheduling frames.
+  void Stop();
+
+  void Pause(bool pause);
+
+  void SetSizeCallback(const VideoStream::SizeCallback& size_callback);
+
+ private:
+  // webrtc::DesktopCapturer::Callback interface.
+  webrtc::SharedMemory* CreateSharedMemory(size_t size) override;
+  void OnCaptureCompleted(webrtc::DesktopFrame* frame) override;
+
+  // Callback for CaptureScheduler.
+  void CaptureNextFrame();
+
+  // Task running on the encoder thread to encode the |frame|.
+  static std::unique_ptr<VideoPacket> EncodeFrame(
+      VideoEncoder* encoder,
+      std::unique_ptr<webrtc::DesktopFrame> frame,
+      bool key_frame_request);
+  void OnFrameEncoded(std::unique_ptr<VideoPacket> packet);
+
+  void SetKeyFrameRequest();
+  bool ClearAndGetKeyFrameRequest();
+
+  // Protects |key_frame_request_|.
+  base::Lock lock_;
+  bool key_frame_request_ = false;
+
+  bool capture_pending_ = false;
+  bool encode_pending_ = false;
+
+  webrtc::DesktopSize frame_size_;
+  webrtc::DesktopVector frame_dpi_;
+  VideoStream::SizeCallback size_callback_;
+
+  // Task runner used to run |encoder_|.
+  scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner_;
+  base::CancelableTaskTracker task_tracker_;
+
+  // Capturer used to capture the screen.
+  std::unique_ptr<webrtc::DesktopCapturer> capturer_;
+
+  std::unique_ptr<base::RepeatingTimer> capture_timer_;
+
+  // Used to send across encoded frames.
+  WebrtcTransport* webrtc_transport_;
+
+  // Used to encode captured frames. Always accessed on the encode thread.
+  std::unique_ptr<VideoEncoder> encoder_;
+
+  base::ThreadChecker thread_checker_;
+  base::TimeTicks last_capture_ticks_;
+
+  base::WeakPtrFactory<WebRtcFrameScheduler> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebRtcFrameScheduler);
+};
+
+}  // namespace protocol
+}  // namespace remoting
+
+#endif  // REMOTING_PROTOCOL_WEBRTC_FRAME_SCHEDULER_H_