System.InvalidCastException on FFDShow Video Decoder on "Standard User" account

2

Exception:

Unable to cast COM object of type 'System.__ComObject' to interface type 'DirectShowLib.IBaseFilter'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{56A86895-0AD4-11CE-B03A-0020AF0BA770}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).

My Graph:
Custom File Source (Async.) -> GDCL Mpeg-4 Demultiplexor -> ffdshow Video Decoder -> Video Renderer

My graph builds and plays correctly on an Administrator account. However when on a "Standard User" account it throws an exception on casting the FFDShow filter.

Code:

IBaseFilter pffdshowVideoDecoder = (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(CLSID_ffdshowVideoDecoder));

Creating the instance does not throw an exception, only when i attempt to cast it under Standard User account.

Additional Info:

  • My program is set to STAThread
  • The creation and casting of the object is on my Main thread
windows
directshow
directshow.net
ffdshow
asked on Stack Overflow Jul 18, 2016 by Michael Chi Lam • edited May 30, 2019 by avariant

0 Answers

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