public override List <string> Scan()
{
List <string> Devices = new List <string>();
List <MFDevice> vcDevices = WMFUtils.GetDevicesByCategory(MFAttributesClsid.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE, CLSID.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID);
foreach (MFDevice device in vcDevices)
{
Devices.Add(device.FriendlyName);
}
return(Devices);
}
public override void Load(string FriendlyName, int FrameRate, int Height, int Width, string Encoding)
{
HResult Return = MFExtern.MFStartup(0x00020070, MFStartup.Full);
if (Return != 0)
{
Console.WriteLine("Constructor: call to MFExtern.MFStartup returned " + Return.ToString());
}
List <MFDevice> vcDevices = WMFUtils.GetDevicesByCategory(MFAttributesClsid.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE, CLSID.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID);
foreach (MFDevice device in vcDevices)
{
if (device.FriendlyName == FriendlyName)
{
UnderlyingDevice = device;
break;
}
}
IMFStreamIndex = GetRequestedStreamFormat(FrameRate, Width, Height, Encoding);
IMFSnapIndex = GetRequestedSnapFormat(Width, Height, Encoding);
}
private List <MFVideoFormatContainer> GetSupportedFormats(int SourceIndex, string FriendlyName)
{
MFDevice UnderlyingDevice = null;
List <MFDevice> vcDevices = WMFUtils.GetDevicesByCategory(MFAttributesClsid.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE, CLSID.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID);
foreach (MFDevice device in vcDevices)
{
if (device.FriendlyName == FriendlyName)
{
UnderlyingDevice = device;
break;
}
}
if (UnderlyingDevice != null)
{
IMFPresentationDescriptor sourcePresentationDescriptor = null;
IMFStreamDescriptor videoStreamDescriptor = null;
IMFMediaTypeHandler typeHandler = null;
List <MFVideoFormatContainer> formatList = new List <MFVideoFormatContainer>();
HResult hr;
IMFMediaSource mediaSource = null;
try
{
// use the device symbolic name to create the media source for the video device. Media sources are objects that generate media data.
// For example, the data might come from a video file, a network stream, or a hardware device, such as a camera. Each
// media source contains one or more streams, and each stream delivers data of one type, such as audio or video.
mediaSource = WMFUtils.GetMediaSourceFromDevice(UnderlyingDevice);
if (mediaSource == null)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to mediaSource == null");
}
// A presentation is a set of related media streams that share a common presentation time.
// we don't need that functionality in this app but we do need to presentation descriptor
// to find out the stream descriptors, these will give us the media types on offer
hr = mediaSource.CreatePresentationDescriptor(out sourcePresentationDescriptor);
if (hr != HResult.S_OK)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to mediaSource.CreatePresentationDescriptor failed. Err=" + hr.ToString());
}
if (sourcePresentationDescriptor == null)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to mediaSource.CreatePresentationDescriptor failed. sourcePresentationDescriptor == null");
}
// Now we get the number of stream descriptors in the presentation.
// A presentation descriptor contains a list of one or more
// stream descriptors.
hr = sourcePresentationDescriptor.GetStreamDescriptorCount(out int sourceStreamCount);
if (hr != HResult.S_OK)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to sourcePresentationDescriptor.GetStreamDescriptorCount failed. Err=" + hr.ToString());
}
if (sourceStreamCount == 0)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to sourcePresentationDescriptor.GetStreamDescriptorCount failed. sourceStreamCount == 0");
}
// look for the video stream
// we require the major type to be video
Guid guidMajorType = WMFUtils.GetMajorMediaTypeFromPresentationDescriptor(sourcePresentationDescriptor, SourceIndex);
if (guidMajorType != MFMediaType.Video)
{
return(new List <MFVideoFormatContainer>());
}
// we also require the stream to be enabled
sourcePresentationDescriptor.SelectStream(1);
hr = sourcePresentationDescriptor.GetStreamDescriptorByIndex(SourceIndex, out bool streamIsSelected, out videoStreamDescriptor);
if (hr != HResult.S_OK)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to sourcePresentationDescriptor.GetStreamDescriptorByIndex(v) failed. Err=" + hr.ToString());
}
if (videoStreamDescriptor == null)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to sourcePresentationDescriptor.GetStreamDescriptorByIndex(v) failed. videoStreamDescriptor == null");
}
// if the stream is not selected (enabled) look for the next
if (streamIsSelected == false)
{
Marshal.ReleaseComObject(videoStreamDescriptor);
videoStreamDescriptor = null;
return(new List <MFVideoFormatContainer>());
}
// Get the media type handler for the stream. IMFMediaTypeHandler
// interface is a standard way of looking at the media types on an stream
hr = videoStreamDescriptor.GetMediaTypeHandler(out typeHandler);
if (hr != HResult.S_OK)
{
throw new Exception("call to videoStreamDescriptor.GetMediaTypeHandler failed. Err=" + hr.ToString());
}
if (typeHandler == null)
{
throw new Exception("call to videoStreamDescriptor.GetMediaTypeHandler failed. typeHandler == null");
}
// Now we get the number of media types in the stream descriptor.
hr = typeHandler.GetMediaTypeCount(out int mediaTypeCount);
if (hr != HResult.S_OK)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to typeHandler.GetMediaTypeCount failed. Err=" + hr.ToString());
}
if (mediaTypeCount == 0)
{
throw new Exception("DisplayVideoFormatsForCurrentCaptureDevice call to typeHandler.GetMediaTypeCount failed. mediaTypeCount == 0");
}
// now loop through each media type
for (int mediaTypeId = 0; mediaTypeId < mediaTypeCount; mediaTypeId++)
{
// Now we have the handler, get the media type.
hr = typeHandler.GetMediaTypeByIndex(mediaTypeId, out IMFMediaType workingMediaType);
if (hr != HResult.S_OK)
{
throw new Exception("GetMediaTypeFromStreamDescriptorById call to typeHandler.GetMediaTypeByIndex failed. Err=" + hr.ToString());
}
if (workingMediaType == null)
{
throw new Exception("GetMediaTypeFromStreamDescriptorById call to typeHandler.GetMediaTypeByIndex failed. workingMediaType == null");
}
MFVideoFormatContainer tmpContainer = MediaTypeInfo.GetVideoFormatContainerFromMediaTypeObject(workingMediaType, UnderlyingDevice);
if (tmpContainer == null)
{
// we failed
throw new Exception("GetSupportedVideoFormatsFromSourceReaderInFormatContainers failed on call to GetVideoFormatContainerFromMediaTypeObject");
}
// now add it
formatList.Add(tmpContainer);
Marshal.ReleaseComObject(workingMediaType);
workingMediaType = null;
}
return(formatList);
}
finally
{
// close and release
if (mediaSource != null)
{
Marshal.ReleaseComObject(mediaSource);
}
if (sourcePresentationDescriptor != null)
{
Marshal.ReleaseComObject(sourcePresentationDescriptor);
}
if (videoStreamDescriptor != null)
{
Marshal.ReleaseComObject(videoStreamDescriptor);
}
if (typeHandler != null)
{
Marshal.ReleaseComObject(typeHandler);
}
}
}
return(new List <MFVideoFormatContainer>());
}