QueryInterface on Filter in DirectShow.NET

Question

I use filters from Video Processing Project and want to set settings of the filters. In c++ it works via ISettingsInterface.

ISettingsInterface * pSettingsInterface = NULL;
pRotateFilter->QueryInterface ( IID_ISettingsInterface, ( void ** ) &pSettingsInterface );
hr = pSettingsInterface->SetParameter ( "rotationmode", "3" );
hr = g_pGraph->AddFilter ( pRotateFilter, L"RotateFilter" );

In the DirectShowlib c# wrappers there is no such interface? There is also no QueryInterface function on the filter.

Answer 1

I solved it by declaring the interface:

 [ComImport, System.Security.SuppressUnmanagedCodeSecurity,Guid("388EEF20-40CC-4752-A0FF-66AA5C4AF8FA"),InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    public interface ISettingsInterface
    {
        [PreserveSig]
        int GetParameter(
            [MarshalAs(UnmanagedType.LPStr)] String type,
            [MarshalAs(UnmanagedType.I4)] int buffersize,
            [In, Out, MarshalAs(UnmanagedType.LPStr)] String value,
            [In, Out, MarshalAs(UnmanagedType.I4)] ref int length
            );

        [PreserveSig]
        int SetParameter(
            [MarshalAs(UnmanagedType.LPStr)] String type,
            [MarshalAs(UnmanagedType.LPStr)] String value
            );

        [PreserveSig]
        int GetParameterSettings(
            [MarshalAs(UnmanagedType.LPStr)] ref String szResult,
            [In] int nSize
            );
    }