protected object setStreamConfigSetting(DShowNET.IAMStreamConfig streamConfig, string fieldName, object newValue)
{
if (streamConfig == null)
{
throw new NotSupportedException();
}
object returnValue = null;
IntPtr pmt = IntPtr.Zero;
DShowNET.AMMediaType mediaType = new DShowNET.AMMediaType();
try
{
// Get the current format info
int hr = streamConfig.GetFormat(out pmt);
if (hr != 0)
{
Marshal.ThrowExceptionForHR(hr);
}
Marshal.PtrToStructure(pmt, mediaType);
// The formatPtr member points to different structures
// dependingon the formatType
object formatStruct;
if (mediaType.formatType == DShowNET.FormatType.WaveEx)
{
formatStruct = new DShowNET.WaveFormatEx();
}
else if (mediaType.formatType == DShowNET.FormatType.VideoInfo)
{
formatStruct = new VideoInfoHeader();
}
else if (mediaType.formatType == DShowNET.FormatType.VideoInfo2)
{
formatStruct = new DShowNET.VideoInfoHeader2();
}
else
{
throw new NotSupportedException("This device does not support a recognized format block.");
}
// Retrieve the nested structure
Marshal.PtrToStructure(mediaType.formatPtr, formatStruct);
// Find the required field
Type structType = formatStruct.GetType();
FieldInfo fieldInfo = structType.GetField(fieldName);
if (fieldInfo == null)
{
throw new NotSupportedException("Unable to find the member '" + fieldName + "' in the format block.");
}
// Update the value of the field
fieldInfo.SetValue(formatStruct, newValue);
// PtrToStructure copies the data so we need to copy it back
Marshal.StructureToPtr(formatStruct, mediaType.formatPtr, false);
// Save the changes
hr = streamConfig.SetFormat(mediaType);
if (hr != 0)
{
Marshal.ThrowExceptionForHR(hr);
}
}
finally
{
//DShowNET.DsUtils.FreeAMMediaType(mediaType);
Marshal.FreeCoTaskMem(pmt);
}
return(returnValue);
}
// Thread entry point
public void WorkerThread()
{
int hr;
Guid cat;
Guid med;
// grabber
Grabber grabber = new Grabber(this);
// objects
object graphObj = null;
object grabberObj = null;
// interfaces
IGraphBuilder graphBuilder = null;
DShowNET.ICaptureGraphBuilder2 captureGraphBuilder = null;
IBaseFilter videoDeviceFilter = null;
IBaseFilter grabberFilter = null;
ISampleGrabber sg = null;
IMediaControl mc = null;
try
{
// Make a new filter graph
graphObj = Activator.CreateInstance(Type.GetTypeFromCLSID(DShowNET.Clsid.FilterGraph, true));
graphBuilder = (IGraphBuilder)graphObj;
// Get the Capture Graph Builder
Guid clsid = DShowNET.Clsid.CaptureGraphBuilder2;
Guid riid = typeof(DShowNET.ICaptureGraphBuilder2).GUID;
captureGraphBuilder = (DShowNET.ICaptureGraphBuilder2)DShowNET.DsBugWO.CreateDsInstance(ref clsid, ref riid);
// Link the CaptureGraphBuilder to the filter graph
hr = captureGraphBuilder.SetFiltergraph((DShowNET.IGraphBuilder)graphBuilder);
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
int rotCookie = 0;
DShowNET.DsROT.AddGraphToRot(graphBuilder, out rotCookie);
// Get the video device and add it to the filter graph
if (deviceMoniker != null)
{
videoDeviceFilter = (IBaseFilter)Marshal.BindToMoniker(deviceMoniker);
hr = graphBuilder.AddFilter(videoDeviceFilter,
"Video Capture Device");
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
}
// create sample grabber, object and filter
grabberObj = Activator.CreateInstance(Type.GetTypeFromCLSID(Clsid.SampleGrabber, true));
grabberFilter = (IBaseFilter)grabberObj;
sg = (ISampleGrabber)grabberObj;
// add sample grabber filter to filter graph
hr = graphBuilder.AddFilter(grabberFilter, "grabber");
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
// Try looking for an video device interleaved media type
IBaseFilter testFilter = videoDeviceFilter;
// grabberFilter (not supported)
object o;
cat = DShowNET.PinCategory.Capture;
med = DShowNET.MediaType.Interleaved;
Guid iid = typeof(DShowNET.IAMStreamConfig).GUID;
hr = captureGraphBuilder.FindInterface(ref cat, ref med, (DShowNET.IBaseFilter)testFilter, ref iid, out o);
if (hr != 0)
{
// If not found, try looking for a video media type
med = MediaType.Video;
hr = captureGraphBuilder.FindInterface(
ref cat, ref med, (DShowNET.IBaseFilter)testFilter, ref iid, out o);
if (hr != 0)
{
o = null;
}
}
// Set the video stream configuration to data member
videoStreamConfig = o as DShowNET.IAMStreamConfig;
o = null;
//modifies the stream size and frame rate
if (modifyStream)
{
//set size of frame
BitmapInfoHeader bmiHeader;
bmiHeader = (BitmapInfoHeader)getStreamConfigSetting(videoStreamConfig, "BmiHeader");
bmiHeader.Width = streamSize.Width;
bmiHeader.Height = streamSize.Height;
setStreamConfigSetting(videoStreamConfig, "BmiHeader", bmiHeader);
//set frame rate (not supported on the cameras we have)
/*
* long avgTimePerFrame = (long)(10000000 / framerate);
* setStreamConfigSetting(videoStreamConfig, "AvgTimePerFrame", avgTimePerFrame);
*/
}
// connect pins (Turns on the video device)
if (graphBuilder.Connect((IPin)AForge.Video.DirectShow.Internals.Tools.GetOutPin((AForge.Video.DirectShow.Internals.IBaseFilter)videoDeviceFilter, 0), (IPin)AForge.Video.DirectShow.Internals.Tools.GetInPin((AForge.Video.DirectShow.Internals.IBaseFilter)grabberFilter, 0)) < 0)
{
throw new ApplicationException("Failed connecting filters");
}
// Set the sample grabber media type settings
AMMediaType mt = new AMMediaType();
mt.majorType = MediaType.Video;
mt.subType = MediaSubType.RGB24;
sg.SetMediaType(mt);
// get media type and set sample grabber parameters
if (sg.GetConnectedMediaType(mt) == 0)
{
VideoInfoHeader vih = (VideoInfoHeader)Marshal.PtrToStructure(mt.formatPtr, typeof(VideoInfoHeader));
if (vih.BmiHeader.Compression != 0)
{
YUYV = true;
grabber.setYUYV(YUYV);
}
grabber.Width = vih.BmiHeader.Width;
grabber.Height = vih.BmiHeader.Height;
//mt.Dispose();
}
// Set various sample grabber properties
sg.SetBufferSamples(false);
sg.SetOneShot(false);
sg.SetCallback(grabber, 1);
if (!preventFreezing)
{
// render
graphBuilder.Render((IPin)AForge.Video.DirectShow.Internals.Tools.GetOutPin((AForge.Video.DirectShow.Internals.IBaseFilter)grabberFilter, 0));
// Do not show active (source) window
IVideoWindow win = (IVideoWindow)graphObj;
win.put_AutoShow(0);
win = null;
}
// get media control
mc = (IMediaControl)graphBuilder;
// run
mc.Run();
while (!stopEvent.WaitOne(0, true))
{
Thread.Sleep(100);
}
mc.StopWhenReady();
}
// catch any exceptions
catch (Exception e)
{
// provide information to clients
if (VideoSourceError != null)
{
VideoSourceError(this, new VideoSourceErrorEventArgs(e.Message));
}
}
// finalization block
finally
{
// release all objects
mc = null;
graphBuilder = null;
captureGraphBuilder = null;
videoDeviceFilter = null;
grabberFilter = null;
sg = null;
if (graphObj != null)
{
Marshal.ReleaseComObject(graphObj);
graphObj = null;
}
if (grabberObj != null)
{
Marshal.ReleaseComObject(grabberObj);
grabberObj = null;
}
}
}
