Use webrtc::DesktopCapturer for screen capturer implementation.

remoting/host/video_scheduler.h

 // Copyright (c) 2012 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_HOST_VIDEO_SCHEDULER_H_
 #define REMOTING_HOST_VIDEO_SCHEDULER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "media/video/capture/screen/screen_capturer.h"
 #include "remoting/codec/video_encoder.h"
 #include "remoting/host/capture_scheduler.h"
 #include "remoting/proto/video.pb.h"
 #include "third_party/skia/include/core/SkSize.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace media {
-class ScreenCaptureData;
 class ScreenCapturer;
 }  // namespace media
 
 namespace remoting {
 
 class CursorShapeInfo;
 
 namespace protocol {
 class CursorShapeInfo;
 class CursorShapeStub;
@@ skipping 30 matching lines @@
 // |                  ............
 // | Time
 // v
 //
 // VideoScheduler 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 VideoScheduler : public base::RefCountedThreadSafe<VideoScheduler>,
-                       public media::ScreenCapturer::Delegate {
+                       public webrtc::DesktopCapturer::Callback,
+                       public media::ScreenCapturer::MouseShapeObserver {
  public:
   // Creates a VideoScheduler running capture, encode and network tasks on the
   // supplied TaskRunners.  Video and cursor shape updates will be pumped to
   // |video_stub| and |client_stub|, which must remain valid until Stop() is
   // called. |capturer| is used to capture frames.
   VideoScheduler(
       scoped_refptr<base::SingleThreadTaskRunner> capture_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> network_task_runner,
       scoped_ptr<media::ScreenCapturer> capturer,
       scoped_ptr<VideoEncoder> encoder,
       protocol::CursorShapeStub* cursor_stub,
       protocol::VideoStub* video_stub);
 
-  // media::ScreenCapturer::Delegate implementation.
-  virtual void OnCaptureCompleted(
-      scoped_refptr<media::ScreenCaptureData> capture_data) OVERRIDE;
+  // webrtc::DesktopCapturer::Callback implementation.
+  virtual webrtc::SharedMemory* CreateSharedMemory(size_t size) OVERRIDE;
+  virtual void OnCaptureCompleted(webrtc::DesktopFrame* frame) OVERRIDE;
+
+  // media::ScreenCapturer::MouseShapeObserver implementation.
   virtual void OnCursorShapeChanged(
       scoped_ptr<media::MouseCursorShape> cursor_shape) OVERRIDE;
 
   // Starts scheduling frame captures.
   void Start();
 
   // Stop scheduling frame captures. This object cannot be re-used once
   // it has been stopped.
   void Stop();
 
   // Pauses or resumes scheduling of frame captures.  Pausing/resuming captures
   // only affects capture scheduling and does not stop/start the capturer.
   void Pause(bool pause);
 
   // Updates the sequence number embedded in VideoPackets.
   // Sequence numbers are used for performance measurements.
   void UpdateSequenceNumber(int64 sequence_number);
 
  private:
   friend class base::RefCountedThreadSafe<VideoScheduler>;
   virtual ~VideoScheduler();
 
   // Capturer thread ----------------------------------------------------------
 
   // Starts the capturer on the capture thread.
   void StartOnCaptureThread();
 
-  // Stops scheduling frame captures on the capture thread, and posts
-  // StopOnEncodeThread() to the network thread when done.
+  // Stops scheduling frame captures on the capture thread.
   void StopOnCaptureThread();
 
   // Schedules the next call to CaptureNextFrame.
   void ScheduleNextCapture();
 
   // Starts the next frame capture, unless there are already too many pending.
   void CaptureNextFrame();
 
   // Called when a frame capture has been encoded & sent to the client.
   void FrameCaptureCompleted();
 
   // Network thread -----------------------------------------------------------
 
   // Send |packet| to the client, unless we are in the process of stopping.
   void SendVideoPacket(scoped_ptr<VideoPacket> packet);
 
   // Callback passed to |video_stub_| for the last packet in each frame, to
   // rate-limit frame captures to network throughput.
   void VideoFrameSentCallback();
 
   // Send updated cursor shape to client.
   void SendCursorShape(scoped_ptr<protocol::CursorShapeInfo> cursor_shape);
 
   // Encoder thread -----------------------------------------------------------
 
   // Encode a frame, passing generated VideoPackets to SendVideoPacket().
-  void EncodeFrame(scoped_refptr<media::ScreenCaptureData> capture_data);
+  void EncodeFrame(scoped_ptr<webrtc::DesktopFrame> frame,
+                   int sequence_number);
 
-  void EncodedDataAvailableCallback(scoped_ptr<VideoPacket> packet);
-
-  // Used to synchronize capture and encode thread teardown, notifying the
-  // network thread when done.
-  void StopOnEncodeThread(scoped_ptr<media::ScreenCapturer> capturer);
+  void EncodedDataAvailableCallback(int sequence_number,
+                                    scoped_ptr<VideoPacket> packet);
 
   // Task runners used by this class.
   scoped_refptr<base::SingleThreadTaskRunner> capture_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
 
   // Used to capture frames. Always accessed on the capture thread.
   scoped_ptr<media::ScreenCapturer> capturer_;
 
   // Used to encode captured frames. Always accessed on the encode thread.
   scoped_ptr<VideoEncoder> encoder_;
 
   // Interfaces through which video frames and cursor shapes are passed to the
   // client. These members are always accessed on the network thread.
   protocol::CursorShapeStub* cursor_stub_;
   protocol::VideoStub* video_stub_;
 
   // Timer used to schedule CaptureNextFrame().
   scoped_ptr<base::OneShotTimer<VideoScheduler> > capture_timer_;
 
-  // Count the number of recordings (i.e. capture or encode) happening.
-  int pending_captures_;
+  // The number of frames being processed, i.e. frames that we are currently
+  // capturing, encoding or sending. The value is capped at 2 to minimize
+  // latency.
+  int pending_frames_;
+
+  // Set when the capturer is capturing a frame.
+  bool capture_pending_;
 
   // True if the previous scheduled capture was skipped.
   bool did_skip_frame_;
 
   // True if capture of video frames is paused.
   bool is_paused_;
 
   // This is a number updated by client to trace performance.
   int64 sequence_number_;
 
   // An object to schedule capturing.
   CaptureScheduler scheduler_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoScheduler);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_VIDEO_SCHEDULER_H_