Tab Capture: Backing store readbacks to YV12 VideoFrames.

content/browser/renderer_host/media/video_capture_controller.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.
 
 // VideoCaptureController is the glue between VideoCaptureHost,
 // VideoCaptureManager and VideoCaptureDevice.
 // It provides functions for VideoCaptureHost to start a VideoCaptureDevice and
 // is responsible for keeping track of shared DIBs and filling them with I420
 // video frames for IPC communication between VideoCaptureHost and
 // VideoCaptureMessageFilter.
@@ skipping 47 matching lines @@
   // prematurely closed.
   void StopSession(int session_id);
 
   // Return a buffer previously given in
   // VideoCaptureControllerEventHandler::OnBufferReady.
   void ReturnBuffer(const VideoCaptureControllerID& id,
                     VideoCaptureControllerEventHandler* event_handler,
                     int buffer_id);
 
   // Implement media::VideoCaptureDevice::EventHandler.
-  virtual void OnIncomingCapturedFrame(const uint8* data,
-                                       int length,
+  virtual void OnIncomingCapturedFrame(const uint8* data, int length,
                                        base::Time timestamp) OVERRIDE;

[wjia(left Chromium), 2013/02/10 06:55:06]

nit: For function declarations and definitions, put each argument on a separate
line
unless the whole declaration fits on one line
(http://dev.chromium.org/developers/coding-style)

[ncarter (slow), 2013/02/11 02:12:42]

Done.

+  virtual void OnIncomingCapturedVideoFrame(media::VideoFrame* frame,
+                                            base::Time timestamp) OVERRIDE;
   virtual void OnError() OVERRIDE;
   virtual void OnFrameInfo(
       const media::VideoCaptureCapability& info) OVERRIDE;
 
  protected:
   virtual ~VideoCaptureController();
 
  private:
   friend class base::RefCountedThreadSafe<VideoCaptureController>;
 
@@ skipping 20 matching lines @@
       const ControllerClients& clients);
   // Find a client of |session_id| in |clients|.
   ControllerClient* FindClient(
       int session_id,
       const ControllerClients& clients);
   // Decide what to do after kStopping state. Dependent on events, controller
   // can stay in kStopping state, or go to kStopped, or restart capture.
   void PostStopping();
   // Check if any DIB is used by client.
   bool ClientHasDIB();
+  // DIB allocator. Locate a free DIB object, reserve it, and return its id
+  // as well as pointers to its color planes. Returns true if successful.
+  bool ReserveSharedMemory(int* buffer_id_out, 
+                           uint8** yplane, 
+                           uint8** uplane, 
+                           uint8** vplane);
 
   // Lock to protect free_dibs_ and owned_dibs_.
   base::Lock lock_;
 
   struct SharedDIB;
   typedef std::map<int /*buffer_id*/, SharedDIB*> DIBMap;
   // All DIBs created by this object.
   // It's modified only on IO thread.
   DIBMap owned_dibs_;
 
@@ skipping 21 matching lines @@
 
   bool device_in_use_;
   VideoCaptureState state_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_CONTROLLER_H_