// Set the Framerate, and video size
private void SetConfigParms(DirectShowLib.ICaptureGraphBuilder2 capGraph, DirectShowLib.IBaseFilter capFilter, int iFrameRate, int iWidth, int iHeight)
{
int hr;
object o;
DirectShowLib.AMMediaType media;
// Find the stream config interface
hr = capGraph.FindInterface(
DirectShowLib.PinCategory.Capture, DirectShowLib.MediaType.Video, capFilter, typeof(DirectShowLib.IAMStreamConfig).GUID, out o);
DirectShowLib.IAMStreamConfig videoStreamConfig = o as DirectShowLib.IAMStreamConfig;
if (videoStreamConfig == null)
{
throw new Exception("Failed to get IAMStreamConfig");
}
// Get the existing format block
hr = videoStreamConfig.GetFormat(out media);
DsError.ThrowExceptionForHR(hr);
// copy out the videoinfoheader
DirectShowLib.VideoInfoHeader v = new DirectShowLib.VideoInfoHeader();
Marshal.PtrToStructure(media.formatPtr, v);
// if overriding the framerate, set the frame rate
if (iFrameRate > 0)
{
v.AvgTimePerFrame = 10000000 / iFrameRate;
}
// if overriding the width, set the width
if (iWidth > 0)
{
v.BmiHeader.Width = iWidth;
}
// if overriding the Height, set the Height
if (iHeight > 0)
{
v.BmiHeader.Height = iHeight;
}
// Copy the media structure back
Marshal.StructureToPtr(v, media.formatPtr, false);
// Set the new format
hr = videoStreamConfig.SetFormat(media);
DsError.ThrowExceptionForHR(hr);
DirectShowLib.DsUtils.FreeAMMediaType(media);
media = null;
}
