private void TestStreamNumFromPin()
        {
            int         hr;
            short       pNum;
            IBaseFilter ibf = m_asfw as IBaseFilter;

            IPin pPin = DsFindPin.ByDirection(ibf, PinDirection.Input, 1);

            hr = m_asfw.StreamNumFromPin(pPin, out pNum);
            DsError.ThrowExceptionForHR(hr);

            Debug.Assert(pNum == 1, "StreamNumFromPin");
        }