/// <summary>
/// 工作线程
/// </summary>
private void WorkerThread()
{
VideoSourceFinishedReasonType reasonToStop = VideoSourceFinishedReasonType.StoppedByUser;
// grabber
Grabber grabber = new Grabber(this);
// objects
object graphObject = null;
object grabberObject = null;
// interfaces
IGraphBuilder graph = null;
IBaseFilter sourceBase = null;
IBaseFilter grabberBase = null;
ISampleGrabber sampleGrabber = null;
IMediaControl mediaControl = null;
IMediaEventEx mediaEvent = null;
try
{
// get type for filter graph
Type type = Type.GetTypeFromCLSID(Clsid.FilterGraph);
if (type == null)
throw new VideoSourceException("Failed creating filter graph");
// create filter graph
graphObject = Activator.CreateInstance(type);
graph = (IGraphBuilder)graphObject;
// create source device's object
graph.AddSourceFilter(Source, "source", out sourceBase);
if (sourceBase == null)
throw new VideoSourceException("Failed creating source filter");
// get type for sample grabber
type = Type.GetTypeFromCLSID(Clsid.SampleGrabber);
if (type == null)
throw new VideoSourceException("Failed creating sample grabber");
// create sample grabber
grabberObject = Activator.CreateInstance(type);
sampleGrabber = (ISampleGrabber)grabberObject;
grabberBase = (IBaseFilter)grabberObject;
// add grabber filters to graph
graph.AddFilter(grabberBase, "grabber");
// set media type
AMMediaType mediaType = new AMMediaType();
mediaType.MajorType = MediaType.Video;
mediaType.SubType = MediaSubType.RGB24;
sampleGrabber.SetMediaType(mediaType);
// connect pins
int pinToTry = 0;
IPin inPin = PinHelper.GetInPin(grabberBase, 0);
IPin outPin = null;
// find output pin acceptable by sample grabber
while (true)
{
outPin = PinHelper.GetOutPin(sourceBase, pinToTry);
if (outPin == null)
{
Marshal.ReleaseComObject(inPin);
throw new VideoSourceException("Cannot find acceptable output video pin in the given source");
}
if (graph.Connect(outPin, inPin) < 0)
{
Marshal.ReleaseComObject(outPin);
outPin = null;
pinToTry++;
}
else
{
break;
}
}
Marshal.ReleaseComObject(outPin);
Marshal.ReleaseComObject(inPin);
// get media type
if (sampleGrabber.GetConnectedMediaType(mediaType) == 0)
{
VideoInfoHeader vih = (VideoInfoHeader)Marshal.PtrToStructure(mediaType.FormatPtr, typeof(VideoInfoHeader));
grabber.Width = vih.BmiHeader.Width;
grabber.Height = vih.BmiHeader.Height;
mediaType.Dispose();
}
// let's do rendering, if we don't need to prevent freezing
if (!PreventFreezing)
{
// render pin
graph.Render(PinHelper.GetOutPin(grabberBase, 0));
// configure video window
IVideoWindow window = (IVideoWindow)graphObject;
window.put_AutoShow(false);
window = null;
}
// configure sample grabber
sampleGrabber.SetBufferSamples(false);
sampleGrabber.SetOneShot(false);
sampleGrabber.SetCallback(grabber, 1);
// disable clock, if someone requested it
if (!ReferenceClockEnabled)
{
IMediaFilter mediaFilter = (IMediaFilter)graphObject;
mediaFilter.SetSyncSource(null);
}
// get media control
mediaControl = (IMediaControl)graphObject;
// get media events' interface
mediaEvent = (IMediaEventEx)graphObject;
IntPtr p1, p2;
DsEvCode code;
// run
mediaControl.Run();
while (!stopEvent.WaitOne(0, false))
{
Thread.Sleep(100);
if (mediaEvent != null)
{
if (mediaEvent.GetEvent(out code, out p1, out p2, 0) >= 0)
{
mediaEvent.FreeEventParams(code, p1, p2);
if (code == DsEvCode.Complete)
{
reasonToStop = VideoSourceFinishedReasonType.EndOfStreamReached;
break;
}
}
}
}
// stop
mediaControl.Stop();
}
catch (Exception ex)
{
// provide information to clients
if (VideoSourceException != null)
{
VideoSourceException(this, new VideoSourceExceptionEventArgs(ex.Message));
}
}
finally
{
// release all objects
graph = null;
grabberBase = null;
sampleGrabber = null;
mediaControl = null;
mediaEvent = null;
if (graphObject != null)
{
Marshal.ReleaseComObject(graphObject);
graphObject = null;
}
if (sourceBase != null)
{
Marshal.ReleaseComObject(sourceBase);
sourceBase = null;
}
if (grabberObject != null)
{
Marshal.ReleaseComObject(grabberObject);
grabberObject = null;
}
}
if (VideoSourceFinished != null)
{
VideoSourceFinished(this, new VideoSourceFinishedEventArgs(reasonToStop));
}
}
private void WorkerThread(bool runGraph)
{
VideoSourceFinishedReasonType reasonToStop = VideoSourceFinishedReasonType.StoppedByUser;
bool isSapshotSupported = false;
// grabber
Grabber videoGrabber = new Grabber(this, false);
Grabber snapshotGrabber = new Grabber(this, true);
// objects
object captureGraphObject = null;
object graphObject = null;
object videoGrabberObject = null;
object snapshotGrabberObject = 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;
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.RGB24;
videoSampleGrabber.SetMediaType(mediaType);
snapshotSampleGrabber.SetMediaType(mediaType);
if (videoControl != null)
{
// find Still Image output pin of the vedio 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);
isSapshotSupported = ((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, desiredFrameSize, desiredFrameRate, ref videoCapabilities);
if (isSapshotSupported)
{
GetPinCapabilitiesAndConfigureSizeAndRate(captureGraph, sourceBase,
PinCategory.StillImage, desiredSnapshotSize, 0, ref snapshotCapabilities);
}
else
{
snapshotCapabilities = new VideoCapabilities[0];
}
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 ((isSapshotSupported) && (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 ((isSapshotSupported) && (provideSnapshots))
{
startTime = DateTime.Now;
videoControl.SetMode(pinStillImage, VideoControlFlags.ExternalTriggerEnable);
}
while (!stopEvent.WaitOne(0, false))
{
Thread.Sleep(100);
if (mediaEvent != null)
{
if (mediaEvent.GetEvent(out code, out p1, out p2, 0) >= 0)
{
mediaEvent.FreeEventParams(code, p1, p2);
if (code == DsEvCode.DeviceLost)
{
reasonToStop = VideoSourceFinishedReasonType.DeviceLost;
break;
}
}
}
if (needToSimulateTrigger)
{
needToSimulateTrigger = false;
if ((isSapshotSupported) && (provideSnapshots))
{
videoControl.SetMode(pinStillImage, VideoControlFlags.Trigger);
}
}
if (needToDisplayPropertyPage)
{
needToDisplayPropertyPage = false;
try
{
// retrieve ISpecifyPropertyPages interface of the device
ISpecifyPropertyPages pPropPages = (ISpecifyPropertyPages)sourceObject;
// get property pages from the property bag
CAUUID caGUID;
pPropPages.GetPages(out caGUID);
// get filter info
FilterInfo filterInfo = new FilterInfo(deviceMoniker);
// create and display the OlePropertyFrame
Win32.OleCreatePropertyFrame(parentWindowForPropertyPage, 0, 0, filterInfo.Name, 1, ref sourceObject, caGUID.cElems, caGUID.pElems, 0, 0, IntPtr.Zero);
// release COM objects
Marshal.FreeCoTaskMem(caGUID.pElems);
}
catch
{
}
}
}
mediaControl.Stop();
}
}
catch (Exception exception)
{
// provide information to clients
if (VideoSourceException != null)
{
VideoSourceException(this, new VideoSourceExceptionEventArgs(exception.Message));
}
}
finally
{
// release all objects
captureGraph = null;
graph = null;
sourceBase = null;
mediaControl = null;
videoControl = null;
mediaEvent = null;
pinStillImage = 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 (VideoSourceFinished != null)
{
VideoSourceFinished(this, new VideoSourceFinishedEventArgs(reasonToStop));
}
}
