Function FindIntefaceInGraph

common/DSUtilLite/DShowUtil.cpp:374–415

pPin - pin of our filter to start searching refiid - guid of the interface to find pUnknown - variable that'll receive the interface

// refiid - guid of the interface to find
// pUnknown - variable that'll receive the interface
HRESULT FindIntefaceInGraph(IPin *pPin, REFIID refiid, void **pUnknown)
{
    PIN_DIRECTION dir;
    pPin->QueryDirection(&dir);

    IPin *pOtherPin = nullptr;
    if (SUCCEEDED(pPin->ConnectedTo(&pOtherPin)) && pOtherPin)
    {
        IBaseFilter *pFilter = GetFilterFromPin(pOtherPin);
        SafeRelease(&pOtherPin);

        HRESULT hrFilter = pFilter->QueryInterface(refiid, pUnknown);
        if (FAILED(hrFilter))
        {
            IEnumPins *pPinEnum = nullptr;
            pFilter->EnumPins(&pPinEnum);

            HRESULT hrPin = E_FAIL;
            for (IPin *pOtherPin2 = nullptr; pPinEnum->Next(1, &pOtherPin2, 0) == S_OK; pOtherPin2 = nullptr)
            {
                PIN_DIRECTION pinDir;
                pOtherPin2->QueryDirection(&pinDir);
                if (dir == pinDir)
                {
                    hrPin = FindIntefaceInGraph(pOtherPin2, refiid, pUnknown);
                }
                SafeRelease(&pOtherPin2);
                if (SUCCEEDED(hrPin))
                    break;
            }
            hrFilter = hrPin;
            SafeRelease(&pPinEnum);
        }
        SafeRelease(&pFilter);

        if (SUCCEEDED(hrFilter))
        {
            return S_OK;
        }
    }
    return E_NOINTERFACE;
}

// pPin - pin of our filter to start searching
// refiid - guid of the interface to find