src/content/renderer/media/rtc_video_capture_delegate.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_RENDERER_MEDIA_RTC_VIDEO_CAPTURE_DELEGATE_H_
   6 #define CONTENT_RENDERER_MEDIA_RTC_VIDEO_CAPTURE_DELEGATE_H_
   7
   8 #include "base/callback.h"
   9 #include "base/message_loop/message_loop_proxy.h"
  10 #include "content/common/media/video_capture.h"
  11 #include "content/renderer/media/video_capture_impl_manager.h"
  12 #include "media/video/capture/video_capture.h"
  13
  14 namespace content {
  15
  16 // Implements a simple reference counted video capturer that guarantees that
  17 // methods in RtcVideoCaptureDelegateEventHandler is only called from when
  18 // StartCapture have been called until after StopCapture have been called.
  19 // It uses VideoCaptureImplManager to start / stop and receive I420 frames
  20 // from Chrome's video capture implementation.
  21 class RtcVideoCaptureDelegate
  22     : public base::RefCountedThreadSafe<RtcVideoCaptureDelegate>,
  23       public media::VideoCapture::EventHandler {
  24  public:
  25   enum CaptureState {
  26     CAPTURE_STOPPED,  // The capturer has been stopped or hasn't started yet.
  27     CAPTURE_RUNNING,  // The capturer has been started successfully and is now
  28                       // capturing.
  29     CAPTURE_FAILED,  // The capturer failed to start.
  30   };
  31
  32   typedef base::Callback<void(const scoped_refptr<media::VideoFrame>&)>
  33       FrameCapturedCallback;
  34   typedef base::Callback<void(CaptureState)> StateChangeCallback;
  35
  36   RtcVideoCaptureDelegate(const media::VideoCaptureSessionId id,
  37                           VideoCaptureImplManager* vc_manager);
  38
  39   void StartCapture(const media::VideoCaptureParams& params,
  40                     const FrameCapturedCallback& captured_callback,
  41                     const StateChangeCallback& state_callback);
  42   void StopCapture();
  43
  44   // media::VideoCapture::EventHandler implementation.
  45   // These functions are called from a thread owned by |vc_manager_|.
  46   virtual void OnStarted(media::VideoCapture* capture) OVERRIDE;
  47   virtual void OnStopped(media::VideoCapture* capture) OVERRIDE;
  48   virtual void OnPaused(media::VideoCapture* capture) OVERRIDE;
  49   virtual void OnError(media::VideoCapture* capture, int error_code) OVERRIDE;
  50   virtual void OnRemoved(media::VideoCapture* capture) OVERRIDE;
  51   virtual void OnFrameReady(
  52       media::VideoCapture* capture,
  53       const scoped_refptr<media::VideoFrame>& frame) OVERRIDE;
  54
  55  private:
  56   friend class base::RefCountedThreadSafe<RtcVideoCaptureDelegate>;
  57
  58   virtual ~RtcVideoCaptureDelegate();
  59
  60   void OnFrameReadyOnCaptureThread(
  61       media::VideoCapture* capture,
  62       const scoped_refptr<media::VideoFrame>& frame);
  63   void OnErrorOnCaptureThread(media::VideoCapture* capture);
  64   void OnRemovedOnCaptureThread(media::VideoCapture* capture);
  65
  66   // The id identifies which video capture device is used for this video
  67   // capture session.
  68   media::VideoCaptureSessionId session_id_;
  69   // The video capture manager handles open/close of video capture devices.
  70   scoped_refptr<VideoCaptureImplManager> vc_manager_;
  71   media::VideoCapture* capture_engine_;
  72
  73   // Accessed on the thread where StartCapture is called.
  74   bool got_first_frame_;
  75   bool error_occured_;
  76
  77   // |captured_callback_| is provided to this class in StartCapture and must be
  78   // valid until StopCapture is called.
  79   FrameCapturedCallback captured_callback_;
  80   // |state_callback_| is provided to this class in StartCapture and must be
  81   // valid until StopCapture is called.
  82   StateChangeCallback state_callback_;
  83   // Message loop of the caller of StartCapture.
  84   scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
  85 };
  86
  87 }  // namespace content
  88
  89 #endif  // CONTENT_RENDERER_MEDIA_RTC_VIDEO_CAPTURE_DELEGATE_H_