Get register extensions for DirectShow automated rendering (e.g. 'avi mov mp4 ts mpg' etc.)

Sub ReaderRegisteredExtensionsGet( _
   ByRef _pbsExtensionsList As String _
) 

void ReaderRegisteredExtensionsGet( 
   out string _pbsExtensionsList
)

procedure ReaderRegisteredExtensionsGet( 
   Out  _pbsExtensionsList: String
); 

void ReaderRegisteredExtensionsGet( 
   [PARAMFLAG::Out] BSTR* _pbsExtensionsList
)