/// <summary>
/// Enumerate the installed MediaFoundation transforms in the specified category
/// </summary>
/// <param name="category">A category from MediaFoundationTransformCategories</param>
/// <returns></returns>
public static IEnumerable <IMFActivate> EnumerateTransforms(Guid category)
{
IntPtr interfacesPointer;
int interfaceCount;
MediaFoundationInterop.MFTEnumEx(category, _MFT_ENUM_FLAG.MFT_ENUM_FLAG_ALL,
null, null, out interfacesPointer, out interfaceCount);
var interfaces = new IMFActivate[interfaceCount];
for (int n = 0; n < interfaceCount; n++)
{
var ptr =
Marshal.ReadIntPtr(new IntPtr(interfacesPointer.ToInt64() + n * Marshal.SizeOf(interfacesPointer)));
interfaces[n] = (IMFActivate)Marshal.GetObjectForIUnknown(ptr);
}
foreach (var i in interfaces)
{
yield return(i);
}
Marshal.FreeCoTaskMem(interfacesPointer);
}
