The class is used to describe video input of devices like video capture boards, which usually provide several inputs.
// Ok button clicked private void okButton_Click(object sender, EventArgs e) { videoDeviceMoniker = videoDevice.Source; // set video size if (videoCapabilitiesDictionary.Count != 0) { VideoCapabilities caps = videoCapabilitiesDictionary[(string)videoResolutionsCombo.SelectedItem]; videoDevice.VideoResolution = caps; captureSize = caps.FrameSize; } if (configureSnapshots) { // set snapshots size if (snapshotCapabilitiesDictionary.Count != 0) { VideoCapabilities caps = snapshotCapabilitiesDictionary[(string)snapshotResolutionsCombo.SelectedItem]; videoDevice.ProvideSnapshots = true; videoDevice.SnapshotResolution = caps; snapshotSize = caps.FrameSize; } } if (availableVideoInputs.Length != 0) { videoInput = availableVideoInputs[videoInputsCombo.SelectedIndex]; videoDevice.CrossbarVideoInput = videoInput; } }
private void WorkerThread(bool runGraph) { ReasonToFinishPlaying reasonToStop = ReasonToFinishPlaying.StoppedByUser; bool isSnapshotSupported = false; // grabber Grabber videoGrabber = new Grabber(this, false, this.pixelFormat); Grabber snapshotGrabber = new Grabber(this, true, this.pixelFormat); // objects object captureGraphObject = null; object graphObject = null; object videoGrabberObject = null; object snapshotGrabberObject = null; object crossbarObject = null; // interfaces ICaptureGraphBuilder2 captureGraph = null; IFilterGraph2 graph = null; IBaseFilter sourceBase = null; IBaseFilter videoGrabberBase = null; IBaseFilter snapshotGrabberBase = null; ISampleGrabber videoSampleGrabber = null; ISampleGrabber snapshotSampleGrabber = null; IMediaControl mediaControl = null; IAMVideoControl videoControl = null; IMediaEventEx mediaEvent = null; IPin pinStillImage = null; IAMCrossbar crossbar = null; try { // get type of capture graph builder Type type = Type.GetTypeFromCLSID(Clsid.CaptureGraphBuilder2); if (type == null) throw new ApplicationException("Failed creating capture graph builder"); // create capture graph builder captureGraphObject = Activator.CreateInstance(type); captureGraph = (ICaptureGraphBuilder2)captureGraphObject; // get type of filter graph type = Type.GetTypeFromCLSID(Clsid.FilterGraph); if (type == null) throw new ApplicationException("Failed creating filter graph"); // create filter graph graphObject = Activator.CreateInstance(type); graph = (IFilterGraph2)graphObject; // set filter graph to the capture graph builder captureGraph.SetFiltergraph((IGraphBuilder)graph); // create source device's object sourceObject = FilterInfo.CreateFilter(deviceMoniker); if (sourceObject == null) throw new ApplicationException("Failed creating device object for moniker"); // get base filter interface of source device sourceBase = (IBaseFilter)sourceObject; // get video control interface of the device try { videoControl = (IAMVideoControl)sourceObject; } catch { // some camera drivers may not support IAMVideoControl interface } // get type of sample grabber type = Type.GetTypeFromCLSID(Clsid.SampleGrabber); if (type == null) throw new ApplicationException("Failed creating sample grabber"); // create sample grabber used for video capture videoGrabberObject = Activator.CreateInstance(type); videoSampleGrabber = (ISampleGrabber)videoGrabberObject; videoGrabberBase = (IBaseFilter)videoGrabberObject; // create sample grabber used for snapshot capture snapshotGrabberObject = Activator.CreateInstance(type); snapshotSampleGrabber = (ISampleGrabber)snapshotGrabberObject; snapshotGrabberBase = (IBaseFilter)snapshotGrabberObject; // add source and grabber filters to graph graph.AddFilter(sourceBase, "source"); graph.AddFilter(videoGrabberBase, "grabber_video"); graph.AddFilter(snapshotGrabberBase, "grabber_snapshot"); // set media type AMMediaType mediaType = new AMMediaType(); mediaType.MajorType = MediaType.Video; mediaType.SubType = MediaSubType.ConvertFrom(pixelFormat); videoSampleGrabber.SetMediaType(mediaType); snapshotSampleGrabber.SetMediaType(mediaType); // get crossbar object to to allows configuring pins of capture card captureGraph.FindInterface(FindDirection.UpstreamOnly, Guid.Empty, sourceBase, typeof(IAMCrossbar).GUID, out crossbarObject); if (crossbarObject != null) { crossbar = (IAMCrossbar)crossbarObject; } isCrossbarAvailable = (crossbar != null); crossbarVideoInputs = ColletCrossbarVideoInputs(crossbar); if (videoControl != null) { // find Still Image output pin of the video device captureGraph.FindPin(sourceObject, PinDirection.Output, PinCategory.StillImage, MediaType.Video, false, 0, out pinStillImage); // check if it support trigger mode if (pinStillImage != null) { VideoControlFlags caps; videoControl.GetCaps(pinStillImage, out caps); isSnapshotSupported = ((caps & VideoControlFlags.ExternalTriggerEnable) != 0); } } // configure video sample grabber videoSampleGrabber.SetBufferSamples(false); videoSampleGrabber.SetOneShot(false); videoSampleGrabber.SetCallback(videoGrabber, 1); // configure snapshot sample grabber snapshotSampleGrabber.SetBufferSamples(true); snapshotSampleGrabber.SetOneShot(false); snapshotSampleGrabber.SetCallback(snapshotGrabber, 1); // configure pins GetPinCapabilitiesAndConfigureSizeAndRate(captureGraph, sourceBase, PinCategory.Capture, videoResolution, ref videoCapabilities); if (isSnapshotSupported) { GetPinCapabilitiesAndConfigureSizeAndRate(captureGraph, sourceBase, PinCategory.StillImage, snapshotResolution, ref snapshotCapabilities); } else { snapshotCapabilities = new VideoCapabilities[0]; } // put video/snapshot capabilities into cache lock (cacheVideoCapabilities) { if ((videoCapabilities != null) && (!cacheVideoCapabilities.ContainsKey(deviceMoniker))) { cacheVideoCapabilities.Add(deviceMoniker, videoCapabilities); } } lock (cacheSnapshotCapabilities) { if ((snapshotCapabilities != null) && (!cacheSnapshotCapabilities.ContainsKey(deviceMoniker))) { cacheSnapshotCapabilities.Add(deviceMoniker, snapshotCapabilities); } } if (runGraph) { // render capture pin captureGraph.RenderStream(PinCategory.Capture, MediaType.Video, sourceBase, null, videoGrabberBase); if (videoSampleGrabber.GetConnectedMediaType(mediaType) == 0) { VideoInfoHeader vih = (VideoInfoHeader)Marshal.PtrToStructure(mediaType.FormatPtr, typeof(VideoInfoHeader)); videoGrabber.Width = vih.BmiHeader.Width; videoGrabber.Height = vih.BmiHeader.Height; mediaType.Dispose(); } if ((isSnapshotSupported) && (provideSnapshots)) { // render snapshot pin captureGraph.RenderStream(PinCategory.StillImage, MediaType.Video, sourceBase, null, snapshotGrabberBase); if (snapshotSampleGrabber.GetConnectedMediaType(mediaType) == 0) { VideoInfoHeader vih = (VideoInfoHeader)Marshal.PtrToStructure(mediaType.FormatPtr, typeof(VideoInfoHeader)); snapshotGrabber.Width = vih.BmiHeader.Width; snapshotGrabber.Height = vih.BmiHeader.Height; mediaType.Dispose(); } } // get media control mediaControl = (IMediaControl)graphObject; // get media events' interface mediaEvent = (IMediaEventEx)graphObject; IntPtr p1, p2; DsEvCode code; // run mediaControl.Run(); if ((isSnapshotSupported) && (provideSnapshots)) { startTime = DateTime.Now; videoControl.SetMode(pinStillImage, VideoControlFlags.ExternalTriggerEnable); } do { if (mediaEvent != null) { if (mediaEvent.GetEvent(out code, out p1, out p2, 0) >= 0) { mediaEvent.FreeEventParams(code, p1, p2); if (code == DsEvCode.DeviceLost) { reasonToStop = ReasonToFinishPlaying.DeviceLost; break; } } } if (needToSetVideoInput) { needToSetVideoInput = false; // set/check current input type of a video card (frame grabber) if (isCrossbarAvailable.Value) { SetCurrentCrossbarInput(crossbar, crossbarVideoInput); crossbarVideoInput = GetCurrentCrossbarInput(crossbar); } } if (needToSimulateTrigger) { needToSimulateTrigger = false; if ((isSnapshotSupported) && (provideSnapshots)) { videoControl.SetMode(pinStillImage, VideoControlFlags.Trigger); } } if (needToDisplayPropertyPage) { needToDisplayPropertyPage = false; DisplayPropertyPage(parentWindowForPropertyPage, sourceObject); if (crossbar != null) { crossbarVideoInput = GetCurrentCrossbarInput(crossbar); } } if (needToDisplayCrossBarPropertyPage) { needToDisplayCrossBarPropertyPage = false; if (crossbar != null) { DisplayPropertyPage(parentWindowForPropertyPage, crossbar); crossbarVideoInput = GetCurrentCrossbarInput(crossbar); } } } while (!stopEvent.WaitOne(100, false)); mediaControl.Stop(); } } catch (Exception exception) { // provide information to clients if (VideoSourceError != null) { VideoSourceError(this, new VideoSourceErrorEventArgs(exception.Message)); } } finally { // release all objects captureGraph = null; graph = null; sourceBase = null; mediaControl = null; videoControl = null; mediaEvent = null; pinStillImage = null; crossbar = null; videoGrabberBase = null; snapshotGrabberBase = null; videoSampleGrabber = null; snapshotSampleGrabber = null; if (graphObject != null) { Marshal.ReleaseComObject(graphObject); graphObject = null; } if (sourceObject != null) { Marshal.ReleaseComObject(sourceObject); sourceObject = null; } if (videoGrabberObject != null) { Marshal.ReleaseComObject(videoGrabberObject); videoGrabberObject = null; } if (snapshotGrabberObject != null) { Marshal.ReleaseComObject(snapshotGrabberObject); snapshotGrabberObject = null; } if (captureGraphObject != null) { Marshal.ReleaseComObject(captureGraphObject); captureGraphObject = null; } if (crossbarObject != null) { Marshal.ReleaseComObject(crossbarObject); crossbarObject = null; } } if (PlayingFinished != null) { PlayingFinished(this, reasonToStop); } }
// Set type of input connected to video output of the crossbar private void SetCurrentCrossbarInput(IAMCrossbar crossbar, VideoInput videoInput) { if (videoInput.Type != PhysicalConnectorType.Default) { int inPinsCount, outPinsCount; // gen number of pins in the crossbar if (crossbar.get_PinCounts(out outPinsCount, out inPinsCount) == 0) { int videoOutputPinIndex = -1; int videoInputPinIndex = -1; int pinIndexRelated; PhysicalConnectorType type; // find index of the video output pin for (int i = 0; i < outPinsCount; i++) { if (crossbar.get_CrossbarPinInfo(false, i, out pinIndexRelated, out type) != 0) continue; if (type == PhysicalConnectorType.VideoDecoder) { videoOutputPinIndex = i; break; } } // find index of the required input pin for (int i = 0; i < inPinsCount; i++) { if (crossbar.get_CrossbarPinInfo(true, i, out pinIndexRelated, out type) != 0) continue; if ((type == videoInput.Type) && (i == videoInput.Index)) { videoInputPinIndex = i; break; } } // try connecting pins if ((videoInputPinIndex != -1) && (videoOutputPinIndex != -1) && (crossbar.CanRoute(videoOutputPinIndex, videoInputPinIndex) == 0)) { crossbar.Route(videoOutputPinIndex, videoInputPinIndex); } } } }
// Get type of input connected to video output of the crossbar private VideoInput GetCurrentCrossbarInput(IAMCrossbar crossbar) { VideoInput videoInput = VideoInput.Default; int inPinsCount, outPinsCount; // gen number of pins in the crossbar if (crossbar.get_PinCounts(out outPinsCount, out inPinsCount) == 0) { int videoOutputPinIndex = -1; int pinIndexRelated; PhysicalConnectorType type; // find index of the video output pin for (int i = 0; i < outPinsCount; i++) { if (crossbar.get_CrossbarPinInfo(false, i, out pinIndexRelated, out type) != 0) continue; if (type == PhysicalConnectorType.VideoDecoder) { videoOutputPinIndex = i; break; } } if (videoOutputPinIndex != -1) { int videoInputPinIndex; // get index of the input pin connected to the output if (crossbar.get_IsRoutedTo(videoOutputPinIndex, out videoInputPinIndex) == 0) { PhysicalConnectorType inputType; crossbar.get_CrossbarPinInfo(true, videoInputPinIndex, out pinIndexRelated, out inputType); videoInput = new VideoInput(videoInputPinIndex, inputType); } } } return videoInput; }
// Collect all video inputs of the specified crossbar private VideoInput[] ColletCrossbarVideoInputs(IAMCrossbar crossbar) { lock (cacheCrossbarVideoInputs) { if (cacheCrossbarVideoInputs.ContainsKey(deviceMoniker)) { return cacheCrossbarVideoInputs[deviceMoniker]; } List<VideoInput> videoInputsList = new List<VideoInput>(); if (crossbar != null) { int inPinsCount, outPinsCount; // gen number of pins in the crossbar if (crossbar.get_PinCounts(out outPinsCount, out inPinsCount) == 0) { // collect all video inputs for (int i = 0; i < inPinsCount; i++) { int pinIndexRelated; PhysicalConnectorType type; if (crossbar.get_CrossbarPinInfo(true, i, out pinIndexRelated, out type) != 0) continue; if (type < PhysicalConnectorType.AudioTuner) { videoInputsList.Add(new VideoInput(i, type)); } } } } VideoInput[] videoInputs = new VideoInput[videoInputsList.Count]; videoInputsList.CopyTo(videoInputs); cacheCrossbarVideoInputs.Add(deviceMoniker, videoInputs); return videoInputs; } }