Directshow preview and save to avi file

IGraphBuilder * g_pGraph = NULL;
ICaptureGraphBuilder2 * g_pCapture = NULL;

IBaseFilter *pMux = NULL;
IFileSinkFilter *pSink = NULL;

///////////////////////////////////////////////////////////////////////////////////////

    // Render the preview pin on the video capture filter
    // Use this instead of g_pGraph->RenderFile

    hr = g_pCapture->SetOutputFileName(&MEDIASUBTYPE_Avi,L"C:\\Example.avi", &pMux, NULL);
    hr = g_pCapture->RenderStream (&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, pSrcFilter, NULL, pMux);
 if (FAILED(hr))
    {
        Msg(TEXT("Couldnt render the video capture stream.  hr=0x%x\r\n")
            TEXT("The capture device may already be in use by another application.\r\n\r\n")
            TEXT("The sample will now close"), hr);
        pSrcFilter->Release();
        return hr;
    }

    hr = g_pCapture->RenderStream (&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video, pSrcFilter, NULL, NULL);

 if (FAILED(hr))
    {
        Msg(TEXT("Couldnt render the video capture stream.  hr=0x%x\r\n")
            TEXT("The capture device may already be in use by another application.\r\n\r\n")
            TEXT("The sample will now close"), hr);
        pSrcFilter->Release();
        return hr;
    }