text: /*
   * libjingle
   * Copyright 2012 Google Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   *  1. Redistributions of source code must retain the above copyright notice,
   *     this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright notice,
   *     this list of conditions and the following disclaimer in the documentation
   *     and/or other materials provided with the distribution.
   *  3. The name of the author may not be used to endorse or promote products
   *     derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
   * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
   * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  // The CaptureManager class manages VideoCapturers to make it possible to share
  // the same VideoCapturers across multiple instances. E.g. if two instances of
  // some class want to listen to same VideoCapturer they can't individually stop
  // and start capturing as doing so will affect the other instance.
  // The class employs reference counting on starting and stopping of capturing of
  // frames such that if anyone is still listening it will not be stopped. The
  // class also provides APIs for attaching VideoRenderers to a specific capturer
  // such that the VideoRenderers are fed frames directly from the capturer. In
  // addition, these frames can be altered before being sent to the capturers by
  // way of VideoProcessors.
  // CaptureManager is Thread-unsafe. This means that none of its APIs may be
  // called concurrently. Note that callbacks are called by the VideoCapturer's
  // thread which is normally a separate unmarshalled thread and thus normally
  // require lock protection.
  
  #ifndef TALK_MEDIA_BASE_CAPTUREMANAGER_H_
  #define TALK_MEDIA_BASE_CAPTUREMANAGER_H_
  
  #include <map>
  #include <vector>
  
  #include "talk/base/sigslotrepeater.h"
  #include "talk/media/base/capturerenderadapter.h"
  #include "talk/media/base/videocapturer.h"
  #include "talk/media/base/videocommon.h"
  
  namespace cricket {
  
  class VideoProcessor;
  class VideoRenderer;
  
  // CaptureManager helper class.
  class VideoCapturerState {
   public:
    static const VideoFormatPod kDefaultCaptureFormat;
  
    static VideoCapturerState* Create(VideoCapturer* video_capturer);
    ~VideoCapturerState() {}
  
    void AddCaptureResolution(const VideoFormat& desired_format);
    bool RemoveCaptureResolution(const VideoFormat& format);
    VideoFormat GetHighestFormat(VideoCapturer* video_capturer) const;
  
    int IncCaptureStartRef();
    int DecCaptureStartRef();
    CaptureRenderAdapter* adapter() { return adapter_.get(); }
    VideoCapturer* GetVideoCapturer() { return adapter()->video_capturer(); }
  
   private:
    struct CaptureResolutionInfo {
      VideoFormat video_format;
      int format_ref_count;
    };
    typedef std::vector<CaptureResolutionInfo> CaptureFormats;
  
    explicit VideoCapturerState(CaptureRenderAdapter* adapter);
  
    talk_base::scoped_ptr<CaptureRenderAdapter> adapter_;
  
    int start_count_;
    CaptureFormats capture_formats_;
  };
  
  class CaptureManager : public sigslot::has_slots<> {
   public:
    CaptureManager() {}
    virtual ~CaptureManager();
  
    virtual bool StartVideoCapture(VideoCapturer* video_capturer,
                                   const VideoFormat& desired_format);
    virtual bool StopVideoCapture(VideoCapturer* video_capturer,
                                  const VideoFormat& format);
  
    virtual bool AddVideoRenderer(VideoCapturer* video_capturer,
                                  VideoRenderer* video_renderer);
    virtual bool RemoveVideoRenderer(VideoCapturer* video_capturer,
                                     VideoRenderer* video_renderer);
  
    virtual bool AddVideoProcessor(VideoCapturer* video_capturer,
                                   VideoProcessor* video_processor);
    virtual bool RemoveVideoProcessor(VideoCapturer* video_capturer,
                                      VideoProcessor* video_processor);
  
    sigslot::repeater2<VideoCapturer*, CaptureState> SignalCapturerStateChange;
  
   private:
    typedef std::map<VideoCapturer*, VideoCapturerState*> CaptureStates;
  
    bool IsCapturerRegistered(VideoCapturer* video_capturer) const;
    bool RegisterVideoCapturer(VideoCapturer* video_capturer);
    void UnregisterVideoCapturer(VideoCapturerState* capture_state);
  
    bool StartWithBestCaptureFormat(VideoCapturerState* capture_info,
                                    VideoCapturer* video_capturer);
  
    VideoCapturerState* GetCaptureState(VideoCapturer* video_capturer) const;
    CaptureRenderAdapter* GetAdapter(VideoCapturer* video_capturer) const;
  
    CaptureStates capture_states_;
  };
  
  }  // namespace cricket
  
  #endif  // TALK_MEDIA_BASE_CAPTUREMANAGER_H_
  