public HResult CreatePresentationDescriptor(out IMFPresentationDescriptor ppPresentationDescriptor)
{
ppPresentationDescriptor = null;
HResult hr = CheckShutdown();
if (MFError.Succeeded(hr) && (_eSourceState == SourceState.SourceState_Opening || _eSourceState == SourceState.SourceState_Invalid || null == _spPresentationDescriptor))
{
hr = HResult.MF_E_NOT_INITIALIZED;
}
if (MFError.Succeeded(hr))
{
hr = _spPresentationDescriptor.Clone(out ppPresentationDescriptor);
}
return(hr);
}