public static LibMWCapture.MWCAP_VIDEO_SIGNAL_STATUS?GetSignalStatus(int channelIndex, out LibMWCapture.MWCAP_AUDIO_VOLUME? audioStatus)
        {
            audioStatus = null;
            ushort[] wpath  = new ushort[512];
            IntPtr   pwpath = GCHandle.Alloc(wpath, GCHandleType.Pinned).AddrOfPinnedObject();

            LibMWCapture.MWGetDevicePath(channelIndex, pwpath);

            var videoChannel = LibMWCapture.MWOpenChannelByPath(pwpath);

            if (videoChannel == IntPtr.Zero)
            {
                return(null);
            }
            try
            {
                audioStatus = PInvokeTools.ReadStruct <LibMWCapture.MWCAP_AUDIO_VOLUME>(ptr =>
                                                                                        LibMWCapture.MWGetAudioVolume(videoChannel, LibMWCapture.MWCAP_AUDIO_NODE.MWCAP_AUDIO_EMBEDDED_CAPTURE, ptr));

                return(PInvokeTools.ReadStruct <LibMWCapture.MWCAP_VIDEO_SIGNAL_STATUS>(
                           ptr =>
                           LibMWCapture.MWGetVideoSignalStatus(videoChannel, ptr)));
            }
            finally
            {
                LibMWCapture.MWCloseChannel(videoChannel);
            }
        }
        public bool OpenVideoChannel(LibMWCapture.MWCAP_CHANNEL_INFO channelInfo, UInt32 dwFourcc, int cx, int cy, UInt32 nFrameDuration, IntPtr hWnd)
        {
            // open video device
            ushort[] wpath  = new ushort[512];
            IntPtr   pwpath = GCHandle.Alloc(wpath, GCHandleType.Pinned).AddrOfPinnedObject();

            LibMWCapture.MWGetDevicePath(channelInfo.byChannelIndex, pwpath);

            Board        = channelInfo.byBoardIndex;
            ChannelIndex = channelInfo.byChannelIndex;

            VideoChannel = LibMWCapture.MWOpenChannelByPath(pwpath);
            if (VideoChannel == IntPtr.Zero)
            {
                return(false);
            }

            video_callback = new LibMWCapture.VIDEO_CAPTURE_STDCALLBACK(video_callback_sub);
            // create video renderer

            bool reverse = dwFourcc == MWCap_FOURCC.MWCAP_FOURCC_BGR24 || dwFourcc == MWCap_FOURCC.MWCAP_FOURCC_BGRA;

            D3DRenderer = LibMWMedia.MWCreateD3DRenderer(cx, cy, dwFourcc, reverse, hWnd);

            if (D3DRenderer == IntPtr.Zero)
            {
                return(false);
            }
            llCount     = 0;
            CurrentTime = RefTime = Libkernel32.GetTickCount();
            uint fourcc        = (uint)dwFourcc;
            int  frameduration = (int)nFrameDuration;

            Video = LibMWCapture.MWCreateVideoCaptureWithStdCallBack(VideoChannel, cx, cy, fourcc, frameduration, video_callback, D3DRenderer);

            if (Video == IntPtr.Zero)
            {
                return(false);
            }

            if (!InitAudioCapture())
            {
                // может быть без аудио если этот источник уже открыт
                //return false;
            }
            return(true);
        }