当我们向对手添加多个用户时，我们无法启动视频通话。当只有一个用户（在您的演示代码中）在对手中时它很有效。
以下是崩溃信息：
07-02 15:53:19.022 499-1208/? E/IMGSRV﹕ :0: gralloc_device_alloc: attach special flag :Format32315659.
07-02 15:53:19.026 499-499/? E/IMGSRV﹕ :0: gralloc_device_alloc: attach special flag :Format32315659.
07-02 15:53:19.028 499-1441/? E/IMGSRV﹕ :0: gralloc_device_alloc: attach special flag :Format32315659.
07-02 15:53:19.281 7442-7673/com.quickblox.sample.videochatwebrtcnew E/VideoCapturerAndroid﹕ startCapture failed
java.lang.RuntimeException: Fail to connect to camera service
at android.hardware.Camera.native_setup(Native Method)
at android.hardware.Camera.<init>(Camera.java:423)
at android.hardware.Camera.open(Camera.java:384)
at org.webrtc.VideoCapturerAndroid.startCaptureOnCameraThread(VideoCapturerAndroid.java:345)
at org.webrtc.VideoCapturerAndroid.access$200(VideoCapturerAndroid.java:72)
at org.webrtc.VideoCapturerAndroid$2.run(VideoCapturerAndroid.java:332)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:153)
at org.webrtc.VideoCapturerAndroid$CameraThread.run(VideoCapturerAndroid.java:295)
07-02 15:53:19.290 135-135/? E/DrmMtkUtil/DrmUtil﹕ checkDcf: not dcf type, dcf version value [80]
07-02 15:53:19.291 135-135/? E/DrmMtkUtil/DrmUtil﹕ checkDcf: not dcf type, dcf version value [80]
07-02 15:53:19.291 135-135/? E/DrmMtkUtil/DrmUtil﹕ checkDcf: not dcf type, dcf version value [80]
07-02 15:53:19.292 134-444/? E/DrmMtkUtil/DrmUtil﹕ parseDcf: not dcf type, dcf version value [80]
07-02 15:53:19.292 134-444/? E/DrmMtkPlugIn﹕ onOpenDecryptSession() : failed to parse dcf file.
07-02 15:53:19.299 135-135/? E/FlvExtractor﹕ [ERROR]:Not an FLV file!!!
07-02 15:53:19.299 135-135/? E/FlvExtractor﹕ [ERROR]:[FLV]mtk_flv_extractor_recognize OUT
07-02 15:53:19.299 135-135/? E/﹕ SniffFLV return 0
07-02 15:53:19.339 499-512/? E/IMGSRV﹕ :0: gralloc_device_alloc: attach special flag :Format32315659.
07-02 15:53:19.362 499-1441/? E/IMGSRV﹕ :0: gralloc_device_alloc: attach special flag :Format32315659.
07-02 15:53:19.831 6945-6955/? E/com.miui.video.MiuiVideoWatermarkProvider﹕ ================getWatermarkList()======================
07-02 15:53:26.883 7442-7673/? E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-2724
java.lang.NullPointerException
at org.webrtc.VideoCapturerAndroid.doStopCaptureOnCamerathread(VideoCapturerAndroid.java:444)
at org.webrtc.VideoCapturerAndroid.stopCaptureOnCameraThread(VideoCapturerAndroid.java:437)
at org.webrtc.VideoCapturerAndroid.access$300(VideoCapturerAndroid.java:72)
at org.webrtc.VideoCapturerAndroid$3.run(VideoCapturerAndroid.java:427)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:153)
at org.webrtc.VideoCapturerAndroid$CameraThread.run(VideoCapturerAndroid.java:295)
07-02 15:53:26.960 517-569/? E/InputDispatcher﹕ channel '42543090 com.quickblox.sample.videochatwebrtcnew/com.quickblox.sample.videochatwebrtcnew.activities.ListUsersActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
07-02 15:53:26.963 135-7666/? E/SurfaceTextureClient﹕ queueBuffer: error queuing buffer to SurfaceTexture, -2147483646
07-02 15:53:26.963 135-7666/? E/MtkCam/DisplayClient﹕ (7666)[enquePrvOps] mpStreamOps->enqueue_buffer failed: status[Unknown error 2147483646(2147483646)], rpImgBuf(0x42fc1478,0x44bb2000) (enquePrvOps){#356:mediatek/hardware/camera/client/DisplayClient/DisplayClient.Stream.cpp}
07-02 15:53:26.995 135-7666/? E/SurfaceTextureClient﹕ queueBuffer: error queuing buffer to SurfaceTexture, -2147483646
07-02 15:53:26.995 135-7666/? E/MtkCam/DisplayClient﹕ (7666)[enquePrvOps] mpStreamOps->enqueue_buffer failed: status[Unknown error 2147483646(2147483646)], rpImgBuf(0x42fc1e08,0x44e74000) (enquePrvOps){#356:mediatek/hardware/camera/client/DisplayClient/DisplayClient.Stream.cpp}
07-02 15:53:27.003 517-569/? E/InputDispatcher﹕ channel '42639cd8 com.quickblox.sample.videochatwebrtcnew/com.quickblox.sample.videochatwebrtcnew.activities.CallActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
07-02 15:53:27.029 135-7666/? E/SurfaceTextureClient﹕ queueBuffer: error queuing buffer to SurfaceTexture, -32
07-02 15:53:27.029 135-7666/? E/MtkCam/DisplayClient﹕ (7666)[enquePrvOps] mpStreamOps->enqueue_buffer failed: status[Broken pipe(32)], rpImgBuf(0x42fc1988,0x46576000) (enquePrvOps){#356:mediatek/hardware/camera/client/DisplayClient/DisplayClient.Stream.cpp}
07-02 15:53:27.290 7750-7750/? E/AEE/DUMPSTATE﹕ copy_file: Copy /proc/7442/status to PROCESS_STATE failed(2), No such file or directory
如何使用Android实现多用户视频通话？