// Retrieve capabilities of a video device
internal VideoCapabilities(IAMStreamConfig videoStreamConfig, int index)
{
AMMediaType mediaType = null;
VideoStreamConfigCaps caps = new VideoStreamConfigCaps();
try
{
// retrieve capabilities struct at the specified index
int hr = videoStreamConfig.GetStreamCaps(index, out mediaType, caps);
if (hr != 0)
Marshal.ThrowExceptionForHR(hr);
if (mediaType.FormatType == FormatType.VideoInfo)
{
VideoInfoHeader videoInfo = (VideoInfoHeader)Marshal.PtrToStructure(mediaType.FormatPtr, typeof(VideoInfoHeader));
FrameSize = new Size(videoInfo.BmiHeader.Width, videoInfo.BmiHeader.Height);
BitCount = videoInfo.BmiHeader.BitCount;
AverageFrameRate = (int)(10000000 / videoInfo.AverageTimePerFrame);
MaximumFrameRate = (int)(10000000 / caps.MinFrameInterval);
}
else if (mediaType.FormatType == FormatType.VideoInfo2)
{
VideoInfoHeader2 videoInfo = (VideoInfoHeader2)Marshal.PtrToStructure(mediaType.FormatPtr, typeof(VideoInfoHeader2));
FrameSize = new Size(videoInfo.BmiHeader.Width, videoInfo.BmiHeader.Height);
BitCount = videoInfo.BmiHeader.BitCount;
AverageFrameRate = (int)(10000000 / videoInfo.AverageTimePerFrame);
MaximumFrameRate = (int)(10000000 / caps.MinFrameInterval);
}
else
{
throw new ApplicationException("Unsupported format found.");
}
// ignore 12 bpp formats for now, since it was noticed they cause issues on Windows 8
// TODO: proper fix needs to be done so ICaptureGraphBuilder2::RenderStream() does not fail
// on such formats
if (BitCount <= 12)
{
throw new ApplicationException("Unsupported format found.");
}
}
finally
{
if (mediaType != null)
mediaType.Dispose();
}
}
// Set resolution for the specified stream configuration
private void SetResolution(IAMStreamConfig streamConfig, VideoCapabilities resolution)
{
if (resolution == null)
{
return;
}
// iterate through device's capabilities to find mediaType for desired resolution
int capabilitiesCount = 0, capabilitySize = 0;
AMMediaType newMediaType = null;
VideoStreamConfigCaps caps = new VideoStreamConfigCaps();
streamConfig.GetNumberOfCapabilities(out capabilitiesCount, out capabilitySize);
for (int i = 0; i < capabilitiesCount; i++)
{
try
{
VideoCapabilities vc = new VideoCapabilities(streamConfig, i);
if (resolution == vc)
{
if (streamConfig.GetStreamCaps(i, out newMediaType, caps) == 0)
{
break;
}
}
}
catch
{
}
}
// set the new format
if (newMediaType != null)
{
streamConfig.SetFormat(newMediaType);
newMediaType.Dispose();
}
}
