1 /* 2 * libjingle 3 * Copyright 2012 Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 // The CaptureManager class manages VideoCapturers to make it possible to share 29 // the same VideoCapturers across multiple instances. E.g. if two instances of 30 // some class want to listen to same VideoCapturer they can't individually stop 31 // and start capturing as doing so will affect the other instance. 32 // The class employs reference counting on starting and stopping of capturing of 33 // frames such that if anyone is still listening it will not be stopped. The 34 // class also provides APIs for attaching VideoRenderers to a specific capturer 35 // such that the VideoRenderers are fed frames directly from the capturer. 36 // CaptureManager is Thread-unsafe. This means that none of its APIs may be 37 // called concurrently. Note that callbacks are called by the VideoCapturer's 38 // thread which is normally a separate unmarshalled thread and thus normally 39 // require lock protection. 40 41 #ifndef TALK_MEDIA_BASE_CAPTUREMANAGER_H_ 42 #define TALK_MEDIA_BASE_CAPTUREMANAGER_H_ 43 44 #include <map> 45 #include <vector> 46 47 #include "talk/media/base/capturerenderadapter.h" 48 #include "talk/media/base/videocommon.h" 49 #include "webrtc/base/sigslotrepeater.h" 50 #include "webrtc/base/thread_checker.h" 51 52 namespace cricket { 53 54 class VideoCapturer; 55 class VideoRenderer; 56 class VideoCapturerState; 57 58 class CaptureManager : public sigslot::has_slots<> { 59 public: 60 enum RestartOptions { 61 kRequestRestart, 62 kForceRestart 63 }; 64 65 CaptureManager(); 66 virtual ~CaptureManager(); 67 68 virtual bool StartVideoCapture(VideoCapturer* video_capturer, 69 const VideoFormat& desired_format); 70 virtual bool StopVideoCapture(VideoCapturer* video_capturer, 71 const VideoFormat& format); 72 73 // Possibly restarts the capturer. If |options| is set to kRequestRestart, 74 // the CaptureManager chooses whether this request can be handled with the 75 // current state or if a restart is actually needed. If |options| is set to 76 // kForceRestart, the capturer is restarted. 77 virtual bool RestartVideoCapture(VideoCapturer* video_capturer, 78 const VideoFormat& previous_format, 79 const VideoFormat& desired_format, 80 RestartOptions options); 81 82 virtual bool AddVideoRenderer(VideoCapturer* video_capturer, 83 VideoRenderer* video_renderer); 84 virtual bool RemoveVideoRenderer(VideoCapturer* video_capturer, 85 VideoRenderer* video_renderer); 86 87 sigslot::repeater2<VideoCapturer*, CaptureState> SignalCapturerStateChange; 88 89 private: 90 typedef std::map<VideoCapturer*, VideoCapturerState*> CaptureStates; 91 92 bool IsCapturerRegistered(VideoCapturer* video_capturer) const; 93 bool RegisterVideoCapturer(VideoCapturer* video_capturer); 94 void UnregisterVideoCapturer(VideoCapturerState* capture_state); 95 96 bool StartWithBestCaptureFormat(VideoCapturerState* capture_info, 97 VideoCapturer* video_capturer); 98 99 VideoCapturerState* GetCaptureState(VideoCapturer* video_capturer) const; 100 CaptureRenderAdapter* GetAdapter(VideoCapturer* video_capturer) const; 101 102 rtc::ThreadChecker thread_checker_; 103 CaptureStates capture_states_; 104 }; 105 106 } // namespace cricket 107 108 #endif // TALK_MEDIA_BASE_CAPTUREMANAGER_H_ 109