webrtc/talk/media/base/capturemanager.h

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/*
* 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 "webrtc/base/sigslotrepeater.h"
#include "talk/media/base/capturerenderadapter.h"
#include "talk/media/base/videocommon.h"
namespace cricket {
class VideoCapturer;
class VideoProcessor;
class VideoRenderer;
class VideoCapturerState;
class CaptureManager : public sigslot::has_slots<> {
public:
enum RestartOptions {
kRequestRestart,
kForceRestart
};
CaptureManager() {}
virtual ~CaptureManager();
virtual bool StartVideoCapture(VideoCapturer* video_capturer,
const VideoFormat& desired_format);
virtual bool StopVideoCapture(VideoCapturer* video_capturer,
const VideoFormat& format);
// Possibly restarts the capturer. If |options| is set to kRequestRestart,
// the CaptureManager chooses whether this request can be handled with the
// current state or if a restart is actually needed. If |options| is set to
// kForceRestart, the capturer is restarted.
virtual bool RestartVideoCapture(VideoCapturer* video_capturer,
const VideoFormat& previous_format,
const VideoFormat& desired_format,
RestartOptions options);
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_