C# IFilterGraph2类代码示例

        /// <summary>
        /// This constructor internally build a DirectShow graph using the given file name parameter.
        /// </summary>
        /// <param name="filename">A media file.</param>
        /// <remarks>This constructor use the BlackListManager class to bane the use of the ffdshow Audio and Video decoders during the Intelligent Connect graph building.</remarks>
        public SimplePlayer(string filename)
        {
            if (string.IsNullOrEmpty(filename))
            throw new ArgumentNullException("filename");

              if (!File.Exists(filename))
            throw new FileNotFoundException();

              this.graphBuilder = (IFilterGraph2)new FilterGraph();

            #if DEBUG
              this.rot = new DsROTEntry(this.graphBuilder);
            #endif

              this.blackListManager = new BlackListManager(this.graphBuilder);

              // blacklist the ffdshow Audio Decoder filter
              this.blackListManager.AddBlackListedFilter(new Guid("0F40E1E5-4F79-4988-B1A9-CC98794E6B55"));
              // blacklist the ffdshow Video Decoder filter
              this.blackListManager.AddBlackListedFilter(new Guid("04FE9017-F873-410E-871E-AB91661A4EF7"));

              int hr = this.graphBuilder.RenderFile(filename, null);
              DsError.ThrowExceptionForHR(hr);

              this.mediaControl = (IMediaControl)this.graphBuilder;
              this.mediaEvent = (IMediaEvent)this.graphBuilder;
        }

        private void BuildGraph(string fileName)
        {
            int hr = 0;

             try
             {
                 graphBuilder = (IFilterGraph2)new FilterGraph();
                 mediaControl = (IMediaControl)graphBuilder;

                 mediaSeeking = (IMediaSeeking)graphBuilder;
                 mediaPosition = (IMediaPosition)graphBuilder;

                 vmr9 = (IBaseFilter)new VideoMixingRenderer9();

                 ConfigureVMR9InWindowlessMode();

                 hr = graphBuilder.AddFilter(vmr9, "Video Mixing Renderer 9");
                 DsError.ThrowExceptionForHR(hr);

                 hr = graphBuilder.RenderFile(fileName, null);
                 DsError.ThrowExceptionForHR(hr);
             }
             catch (Exception e)
             {
                 CloseInterfaces();
                 MessageBox.Show("An error occured during the graph building : \r\n\r\n" + e.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
             }
        }

 private static bool ConnectFilter(IFilterGraph2 graphBuilder, IBaseFilter networkFilter, IBaseFilter tunerFilter)
 {
   IPin pinOut = DsFindPin.ByDirection(networkFilter, PinDirection.Output, 0);
   IPin pinIn = DsFindPin.ByDirection(tunerFilter, PinDirection.Input, 0);
   int hr = graphBuilder.Connect(pinOut, pinIn);
   return (hr == 0);
 }

        public PlayerCore(string file)
        {
            graphBuilder = (new FilterGraph()) as IFilterGraph2;
            if (graphBuilder == null) return;
            mediaControl = graphBuilder as IMediaControl;
            mediaSeeking = graphBuilder as IMediaSeeking;
            audioControl = graphBuilder as IBasicAudio;
            if (mediaControl == null || mediaSeeking == null || audioControl == null) return;
            //int hr = mediaControl.RenderFile(file);
            FileInfo info = new FileInfo(file);
            ISupport support = Supports.Instance[info.Extension];
            int hr = -1;
            if (support != null)
                hr = support.RenderGraph(graphBuilder, file);
            else
                hr = mediaControl.RenderFile(file);

            fileName = file;
            if (hr != 0) errorStack.Push(hr);
            if (hr != 0) return;
            mediaSeeking.SetTimeFormat(TimeFormat.MediaTime);
            isValidate = true;
            window = graphBuilder as IVideoWindow;
            if (window != null)
            {
                int width = 0;
                int height = 0;
                window.get_Width(out width);
                window.get_Height(out height);
                nativeSize = new Size(width, height);
            }
        }

        public void BuildGraph(ITuningSpace tuningSpace)
        {
            this.graphBuilder = (IFilterGraph2) new FilterGraph();
              rot = new DsROTEntry(this.graphBuilder);

              // Method names should be self explanatory
              AddNetworkProviderFilter(tuningSpace);
              AddMPEG2DemuxFilter();
              AddAndConnectBDABoardFilters();
              AddTransportStreamFiltersToGraph();
              AddRenderers();
              ConfigureVMR9InWindowlessMode();
              ConnectFilters();
        }

    /// <summary>
    /// Initializes a new instance of the <see cref="HDPVRChannel"/> class.
    /// </summary>
    public HDPVRChannel(TvCardHDPVR card, String deviceType, Int32 subchannelId, IBaseFilter filterTsWriter, IFilterGraph2 graphBuilder)
    {
      _eventPMT = new ManualResetEvent(false);
      _graphState = GraphState.Created;
      _graphBuilder = graphBuilder;
      _channelInfo = new ChannelInfo();
      _pmtPid = -1;
      _subChannelIndex = -1;

      // Keep a reference to the card for quality control.
      _card = card;
      _deviceType = deviceType;

      _tsFilterInterface = (ITsFilter)filterTsWriter;
      _tsFilterInterface.AddChannel(ref _subChannelIndex);
      _subChannelId = subchannelId;
      _timeshiftFileName = "";
      _recordingFileName = "";
      _pmtData = null;
      _pmtLength = 0;

      _grabTeletext = false;
      _mdplugs = null;
    }

        public int RenderGraph(IFilterGraph2 graph, string fileName)
        {
            FileInfo info = new FileInfo(fileName);
            string ext = info.Extension;
            bool has = false;
            foreach (string s in exts)
            {
                if (s == ext)
                {
                    has = true;
                    break;
                }
            }

            if (!has)
                return -1;

            //just render file

            IMediaControl mediaControl = graph as IMediaControl;
            if( mediaControl == null ) return -1;

            return mediaControl.RenderFile(fileName);
        }

 /// <summary>
 /// Creates the filter by trying to detect it
 /// </summary>
 /// <param name="crossbar">The crossbar componen</param>
 /// <param name="tuner">The tuner component</param>
 /// <param name="graph">The stored graph</param>
 /// <param name="graphBuilder">The graphBuilder</param>
 /// <returns>true, if the graph building was successful</returns>
 private bool CreateAutomaticFilterInstance(Graph graph, Tuner tuner, Crossbar crossbar, IFilterGraph2 graphBuilder)
 {
   //get all tv audio tuner devices on this system
   DsDevice[] devices = null;
   try
   {
     devices = DsDevice.GetDevicesOfCat(FilterCategory.AMKSTVAudio);
     devices = DeviceSorter.Sort(devices, tuner.TunerName, crossbar.CrossBarName);
   }
   catch (Exception)
   {
     Log.Log.WriteFile("analog: AddTvAudioFilter no tv audio devices found - Trying TvTuner filter");
   }
   if (devices != null && devices.Length > 0)
   {
     // try each tv audio tuner
     for (int i = 0; i < devices.Length; i++)
     {
       IBaseFilter tmp;
       Log.Log.WriteFile("analog: AddTvAudioFilter try:{0} {1}", devices[i].Name, i);
       //if tv audio tuner is currently in use we can skip it
       if (DevicesInUse.Instance.IsUsed(devices[i]))
         continue;
       int hr;
       try
       {
         //add tv audio tuner to graph
         hr = graphBuilder.AddSourceFilterForMoniker(devices[i].Mon, null, devices[i].Name, out tmp);
       }
       catch (Exception)
       {
         Log.Log.WriteFile("analog: cannot add filter to graph");
         continue;
       }
       if (hr != 0)
       {
         //failed to add tv audio tuner to graph, continue with the next one
         if (tmp != null)
         {
           graphBuilder.RemoveFilter(tmp);
           Release.ComObject("tvAudioFilter filter", tmp);
         }
         continue;
       }
       // try connecting the tv tuner-> tv audio tuner
       if (FilterGraphTools.ConnectPin(graphBuilder, tuner.AudioPin, tmp, 0))
       {
         // Got it !
         // Connect tv audio tuner to the crossbar
         IPin pin = DsFindPin.ByDirection(tmp, PinDirection.Output, 0);
         hr = graphBuilder.Connect(pin, crossbar.AudioTunerIn);
         if (hr < 0)
         {
           //failed
           graphBuilder.RemoveFilter(tmp);
           Release.ComObject("audiotuner pinin", pin);
           Release.ComObject("audiotuner filter", tmp);
         }
         else
         {
           //succeeded. we're done
           Log.Log.WriteFile("analog: AddTvAudioFilter succeeded:{0}", devices[i].Name);
           Release.ComObject("audiotuner pinin", pin);
           _filterTvAudioTuner = tmp;
           _audioDevice = devices[i];
           DevicesInUse.Instance.Add(_audioDevice);
           _tvAudioTunerInterface = tuner.Filter as IAMTVAudio;
           break;
         }
       }
       else
       {
         // cannot connect tv tuner-> tv audio tuner, try next one...
         graphBuilder.RemoveFilter(tmp);
         Release.ComObject("audiotuner filter", tmp);
       }
     }
   }
   if (_filterTvAudioTuner == null)
   {
     Log.Log.WriteFile("analog: AddTvAudioFilter no tv audio devices found - Trying TvTuner filter");
     int hr = graphBuilder.Connect(tuner.AudioPin, crossbar.AudioTunerIn);
     if (hr != 0)
     {
       Log.Log.Error("analog: unable to add TvAudioTuner to graph - even TvTuner as TvAudio fails");
       mode = TvAudioVariant.Unavailable;
     }
     else
     {
       Log.Log.WriteFile("analog: AddTvAudioFilter connected TvTuner with Crossbar directly succeeded!");
       mode = TvAudioVariant.TvTunerConnection;
       _tvAudioTunerInterface = tuner.Filter as IAMTVAudio;
//.........这里部分代码省略.........

        /// <summary> build the capture graph for grabber. </summary>
        private void SetupGraph(DsDevice dev, AMMediaType media)
        {
            int hr;

            ISampleGrabber sampGrabber = null;
            IBaseFilter capFilter = null;
            ICaptureGraphBuilder2 capGraph = null;

            // Get the graphbuilder object
            m_FilterGraph = (IFilterGraph2) new FilterGraph();
            m_mediaCtrl = m_FilterGraph as IMediaControl;
            try
            {
                // Get the ICaptureGraphBuilder2
                capGraph = (ICaptureGraphBuilder2) new CaptureGraphBuilder2();

                // Get the SampleGrabber interface
                sampGrabber = (ISampleGrabber) new SampleGrabber();

                // Start building the graph
                hr = capGraph.SetFiltergraph( m_FilterGraph );
                DsError.ThrowExceptionForHR( hr );

                // Add the video device
                hr = m_FilterGraph.AddSourceFilterForMoniker(dev.Mon, null, "Video input", out capFilter);
                DsError.ThrowExceptionForHR( hr );

                // add video crossbar
                // thanks to Andrew Fernie - this is to get tv tuner cards working
                IAMCrossbar crossbar = null;
                object o;

                hr = capGraph.FindInterface(PinCategory.Capture, MediaType.Video, capFilter, typeof(IAMCrossbar).GUID, out o);
                if (hr >= 0)
                {
                    crossbar = (IAMCrossbar)o;
                    int oPin, iPin;
                    int ovLink, ivLink;
                    ovLink = ivLink = 0;

                    crossbar.get_PinCounts(out oPin, out iPin);
                    int pIdxRel;
                    PhysicalConnectorType tp;
                    for (int i = 0; i < iPin; i++)
                    {
                        crossbar.get_CrossbarPinInfo(true, i, out pIdxRel, out tp);
                        if (tp == PhysicalConnectorType.Video_Composite) ivLink = i;
                    }

                    for (int i = 0; i < oPin; i++)
                    {
                        crossbar.get_CrossbarPinInfo(false, i, out pIdxRel, out tp);
                        if (tp == PhysicalConnectorType.Video_VideoDecoder) ovLink = i;
                    }

                    try
                    {
                        crossbar.Route(ovLink, ivLink);
                        o = null;
                    }

                    catch
                    {
                        throw new Exception("Failed to get IAMCrossbar");
                    }
                }

                //add AVI Decompressor
                IBaseFilter pAVIDecompressor = (IBaseFilter)new AVIDec();
                hr = m_FilterGraph.AddFilter(pAVIDecompressor, "AVI Decompressor");
                DsError.ThrowExceptionForHR(hr);

                //
                IBaseFilter baseGrabFlt = (IBaseFilter)	sampGrabber;
                ConfigureSampleGrabber(sampGrabber);

                // Add the frame grabber to the graph
                hr = m_FilterGraph.AddFilter( baseGrabFlt, "Ds.NET Grabber" );
                DsError.ThrowExceptionForHR( hr );

                SetConfigParms(capGraph, capFilter, media);

                hr = capGraph.RenderStream(PinCategory.Capture, MediaType.Video, capFilter, pAVIDecompressor, baseGrabFlt);
                if (hr < 0)
                {
                    hr = capGraph.RenderStream(PinCategory.Capture, MediaType.Video, capFilter, null, baseGrabFlt);
                }

                DsError.ThrowExceptionForHR( hr );

                SaveSizeInfo(sampGrabber);
            }
            finally
            {
                if (capFilter != null)
                {
                    Marshal.ReleaseComObject(capFilter);
                    capFilter = null;
                }
//.........这里部分代码省略.........

 protected RadioBase()
 {
     filterGraph = (IFilterGraph2)new FilterGraph();
     AddSourceFilter();
 }

        // Build the capture graph for grabber and renderer.</summary>
        // (Control to show video in, Filename to play)
        private void SetupGraph(string FileName)
        {
            int hr;

            // Get the graphbuilder object
            m_FilterGraph = new FilterGraph() as IFilterGraph2;

            // Get a ICaptureGraphBuilder2 to help build the graph
            ICaptureGraphBuilder2 icgb2 = new CaptureGraphBuilder2() as ICaptureGraphBuilder2;

            try
            {
                // Link the ICaptureGraphBuilder2 to the IFilterGraph2
                hr = icgb2.SetFiltergraph(m_FilterGraph);
                DsError.ThrowExceptionForHR(hr);

                // Add the filters necessary to render the file.  This function will
                // work with a number of different file types.
                IBaseFilter sourceFilter = null;
                hr = m_FilterGraph.AddSourceFilter(FileName, FileName, out sourceFilter);
                DsError.ThrowExceptionForHR(hr);

                // Get the SampleGrabber interface
                m_sampGrabber = (ISampleGrabber)new SampleGrabber();
                IBaseFilter baseGrabFlt = (IBaseFilter)m_sampGrabber;

                // Configure the Sample Grabber
                ConfigureSampleGrabber(m_sampGrabber);

                // Add it to the filter
                hr = m_FilterGraph.AddFilter(baseGrabFlt, "Ds.NET Grabber");
                DsError.ThrowExceptionForHR(hr);

                // Add the null renderer to the graph
                IBaseFilter nullrenderer = new NullRenderer() as IBaseFilter;
                hr = m_FilterGraph.AddFilter(nullrenderer, "Null renderer");
                DsError.ThrowExceptionForHR(hr);

                // Connect the pieces together, use the default renderer
                hr = icgb2.RenderStream(null, null, sourceFilter, baseGrabFlt, nullrenderer);
                DsError.ThrowExceptionForHR(hr);

                // Now that the graph is built, read the dimensions of the bitmaps we'll be getting
                SaveSizeInfo(m_sampGrabber);

                // Grab some other interfaces
                m_mediaEvent = m_FilterGraph as IMediaEvent;
                m_mediaCtrl = m_FilterGraph as IMediaControl;
            }
            finally
            {
                if (icgb2 != null)
                {
                    Marshal.ReleaseComObject(icgb2);
                    icgb2 = null;
                }
            }
            #if DEBUG
            // Double check to make sure we aren't releasing something
            // important.
            GC.Collect();
            GC.WaitForPendingFinalizers();
            #endif
        }

        public void SetupGraph(DsDevice dev, bool runOCR, VideoFormatHelper.SupportedVideoFormat selectedFormat, ref float iFrameRate, ref int iWidth, ref int iHeight)
        {
            try
            {
                filterGraph = (IFilterGraph2)new FilterGraph();
                mediaCtrl = filterGraph as IMediaControl;

                capBuilder = (ICaptureGraphBuilder2)new CaptureGraphBuilder2();

                samplGrabber = (ISampleGrabber)new SampleGrabber();

                int hr = capBuilder.SetFiltergraph(filterGraph);
                DsError.ThrowExceptionForHR(hr);

                if (Settings.Default.VideoGraphDebugMode)
                {
                    if (rot != null)
                    {
                        rot.Dispose();
                        rot = null;
                    }
                    rot = new DsROTEntry(filterGraph);
                }

                SetupGraphInternal(dev, selectedFormat, ref iFrameRate, ref iWidth, ref iHeight);

                // Now that sizes are fixed/known, store the sizes
                SaveSizeInfo(samplGrabber);

                crossbar = CrossbarHelper.SetupTunerAndCrossbar(capBuilder, capFilter);

                latestBitmap = new Bitmap(iWidth, iHeight, PixelFormat.Format24bppRgb);
                fullRect = new Rectangle(0, 0, latestBitmap.Width, latestBitmap.Height);

                NativeHelpers.SetupCamera(
                    Settings.Default.CameraModel,
                    iWidth, iHeight,
                    Settings.Default.HorizontalFlip,
                    Settings.Default.VerticalFlip,
                    Settings.Default.IsIntegrating,
                    (float)Settings.Default.MinSignatureDiffRatio,
                    (float)Settings.Default.MinSignatureDiff,
                    Settings.Default.GammaDiff,
                    Settings.Default.ForceNewFrameOnLockedRate,
                    dev.Name,
                    selectedFormat.AsSerialized(),
                    selectedFormat.FrameRate);

                NativeHelpers.SetupAav(Settings.Default.RecordStatusSectionOnly ? AavImageLayout.StatusSectionOnly : Settings.Default.AavImageLayout, Settings.Default.AavCompression);

                ocrEnabled = false;
                string errorMessage;

                if (runOCR)
                {
                    OcrConfiguration ocrConfig = OcrSettings.Instance[Settings.Default.SelectedOcrConfiguration];

                    errorMessage = NativeHelpers.SetupBasicOcrMetrix(ocrConfig);
                    if (errorMessage != null && callbacksObject != null)
                        callbacksObject.OnError(-1, errorMessage);
                    else
                    {
                        NativeHelpers.SetupOcr(ocrConfig);
                        ocrEnabled = true;
                    }
                }
                else
                {
                    errorMessage = NativeHelpers.SetupTimestampPreservation(false, 0, 0);
                    if (errorMessage != null && callbacksObject != null)
                        callbacksObject.OnError(-1, errorMessage);
                }
            }
            catch
            {
                CloseResources();

                if (callbacksObject != null)
                    callbacksObject.OnError(-1, "Error initialising the camera. The selected video mode may not be supported by the camera.");

                throw;
            }
        }

        /// <summary> build the capture graph for grabber. </summary>
        private void SetupGraph(string FileName)
        {
            int hr;

            ISampleGrabber sampGrabber = null;
            IBaseFilter baseGrabFlt = null;
            IBaseFilter capFilter = null;
            IBaseFilter nullrenderer = null;

            // Get the graphbuilder object
            m_FilterGraph = new FilterGraph() as IFilterGraph2;
            m_mediaCtrl = m_FilterGraph as IMediaControl;
            m_MediaEvent = m_FilterGraph as IMediaEvent;

            IMediaFilter mediaFilt = m_FilterGraph as IMediaFilter;

            try
            {
            #if DEBUG
                m_rot = new DsROTEntry(m_FilterGraph);
            #endif

                // Add the video source
                hr = m_FilterGraph.AddSourceFilter(FileName, "Ds.NET FileFilter", out capFilter);
                DsError.ThrowExceptionForHR(hr);

                // Get the SampleGrabber interface
                sampGrabber = new SampleGrabber() as ISampleGrabber;
                baseGrabFlt = sampGrabber as IBaseFilter;

                ConfigureSampleGrabber(sampGrabber);

                // Add the frame grabber to the graph
                hr = m_FilterGraph.AddFilter(baseGrabFlt, "Ds.NET Grabber");
                DsError.ThrowExceptionForHR(hr);

                // ---------------------------------
                // Connect the file filter to the sample grabber

                // Hopefully this will be the video pin, we could check by reading it's mediatype
                IPin iPinOut = DsFindPin.ByDirection(capFilter, PinDirection.Output, 0);

                // Get the input pin from the sample grabber
                IPin iPinIn = DsFindPin.ByDirection(baseGrabFlt, PinDirection.Input, 0);

                hr = m_FilterGraph.Connect(iPinOut, iPinIn);
                DsError.ThrowExceptionForHR(hr);

                // Add the null renderer to the graph
                nullrenderer = new NullRenderer() as IBaseFilter;
                hr = m_FilterGraph.AddFilter(nullrenderer, "Null renderer");
                DsError.ThrowExceptionForHR(hr);

                // ---------------------------------
                // Connect the sample grabber to the null renderer

                iPinOut = DsFindPin.ByDirection(baseGrabFlt, PinDirection.Output, 0);
                iPinIn = DsFindPin.ByDirection(nullrenderer, PinDirection.Input, 0);

                hr = m_FilterGraph.Connect(iPinOut, iPinIn);
                DsError.ThrowExceptionForHR(hr);

                // Turn off the clock.  This causes the frames to be sent
                // thru the graph as fast as possible
                hr = mediaFilt.SetSyncSource(null);
                DsError.ThrowExceptionForHR(hr);

                // Read and cache the image sizes
                SaveSizeInfo(sampGrabber);
            }
            finally
            {
                if (capFilter != null)
                {
                    Marshal.ReleaseComObject(capFilter);
                    capFilter = null;
                }
                if (sampGrabber != null)
                {
                    Marshal.ReleaseComObject(sampGrabber);
                    sampGrabber = null;
                }
                if (nullrenderer != null)
                {
                    Marshal.ReleaseComObject(nullrenderer);
                    nullrenderer = null;
                }
            }
        }

        /// <summary> build the capture graph for grabber. </summary>
        private void SetupGraph(string FileName, Control hWin)
        {
            int hr;

            IBaseFilter ibfRenderer = null;
            ISampleGrabber sampGrabber = null;
            IBaseFilter capFilter = null;
            IPin iPinInFilter = null;
            IPin iPinOutFilter = null;
            IPin iPinInDest = null;
            IBasicAudio basicAudio = null;

            // Get the graphbuilder object
            m_FilterGraph = new FilterGraph() as IFilterGraph2;
            #if DEBUG
            m_rot = new DsROTEntry(m_FilterGraph);
            #endif

            try
            {
                // Get the SampleGrabber interface
                sampGrabber = new SampleGrabber() as ISampleGrabber;

                // Add the video source
                hr = m_FilterGraph.AddSourceFilter(FileName, "Ds.NET FileFilter", out capFilter);
                DsError.ThrowExceptionForHR(hr);

                // Hopefully this will be the video pin
                IPin iPinOutSource = DsFindPin.ByDirection(capFilter, PinDirection.Output, 0);

                IBaseFilter baseGrabFlt = sampGrabber as IBaseFilter;
                ConfigureSampleGrabber(sampGrabber);

                iPinInFilter = DsFindPin.ByDirection(baseGrabFlt, PinDirection.Input, 0);
                iPinOutFilter = DsFindPin.ByDirection(baseGrabFlt, PinDirection.Output, 0);

                // Add the frame grabber to the graph
                hr = m_FilterGraph.AddFilter(baseGrabFlt, "Ds.NET Grabber");
                DsError.ThrowExceptionForHR(hr);

                hr = m_FilterGraph.Connect(iPinOutSource, iPinInFilter);
                DsError.ThrowExceptionForHR(hr);

                // Get the default video renderer
                ibfRenderer = (IBaseFilter)new VideoRendererDefault();

                // Add it to the graph
                hr = m_FilterGraph.AddFilter(ibfRenderer, "Ds.NET VideoRendererDefault");
                DsError.ThrowExceptionForHR(hr);
                iPinInDest = DsFindPin.ByDirection(ibfRenderer, PinDirection.Input, 0);

                // Connect the graph.  Many other filters automatically get added here
                hr = m_FilterGraph.Connect(iPinOutFilter, iPinInDest);
                DsError.ThrowExceptionForHR(hr);

                SaveSizeInfo(sampGrabber);

                // Set the output window

                IVideoWindow videoWindow = m_FilterGraph as IVideoWindow;
                hr = videoWindow.put_Owner(hWin.Handle);
                DsError.ThrowExceptionForHR(hr);

                hr = videoWindow.put_WindowStyle(WindowStyle.Child | WindowStyle.ClipChildren | WindowStyle.ClipSiblings);
                DsError.ThrowExceptionForHR(hr);

                hr = videoWindow.put_Visible(OABool.True);
                DsError.ThrowExceptionForHR(hr);

                //TODO : Need a better way to hide the video in the parent Window
                Rectangle rc = hWin.ClientRectangle;
                if (mParentWindowDisplay)
                    hr = videoWindow.SetWindowPosition(0, 0, rc.Right, rc.Bottom);
                else
                    hr = videoWindow.SetWindowPosition(0, 0, 0, 0);
                DsError.ThrowExceptionForHR(hr);

                IGraphBuilder graphBuilder = m_FilterGraph as IGraphBuilder;
                ICaptureGraphBuilder2 captureGraphBuilder = (ICaptureGraphBuilder2)new CaptureGraphBuilder2();

                // Attach the filter graph to the capture graph
                hr = captureGraphBuilder.SetFiltergraph(graphBuilder);
                DsError.ThrowExceptionForHR(hr);

                hr = captureGraphBuilder.RenderStream(null, MediaType.Audio, capFilter, null, null);

            }
            finally
            {
                if (capFilter != null)
                {
                    Marshal.ReleaseComObject(capFilter);
                    capFilter = null;
                }
                if (sampGrabber != null)
                {
                    Marshal.ReleaseComObject(sampGrabber);
                    sampGrabber = null;
                }
//.........这里部分代码省略.........

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            base.Dispose( disposing );

            if (m_rot != null)
            {
                m_rot.Dispose();
                m_rot = null;
            }
            if (graphBuilder != null)
            {
                (graphBuilder as IMediaControl).Stop();
                Marshal.ReleaseComObject(graphBuilder);
                graphBuilder = null;
            }
        }