Usando un filtro DirectShow sin registrarlo, a través de una CoCreateInstance privada

Así que básicamente leí esto,http://www.gdcl.co.uk/2011/June/UnregisteredFilters.htm.

Lo que te dice cómo usar los filtros sin registrarlos. Hay dos métodos, nuevos y que usan una CoCreateInstance privada. Estoy tratando de usar el método CoCreateInstance.

En la muestra del sitio, el código aparece como,

IUnknownPtr pUnk;
HRESULT hr = CreateObjectFromPath(TEXT("c:\\path\\to\\myfilter.dll"), IID_MyFilter, &pUnk);
if (SUCCEEDED(hr))
{
    IBaseFilterPtr pFilter = pUnk;
    pGraph->AddFilter(pFilter, L"Private Filter");
    pGraph->RenderFile(pMediaClip, NULL);
}

Mi código de la siguiente manera,

IUnknownPtr pUnk;
HRESULT hr = CreateObjectFromPath(TEXT("c:\\filters\\mp4demux.dll"), IID_BaseFilter, &pUnk);
if (SUCCEEDED(hr))
{
  //add functionality
}

Supongo que IID_BaseFilter es lo que se supone que debo usar, es lo que uso para otros filtros. Pero me aparece el error "ClassFactory no puede suministrar la clase solicitada".

¿Me estoy perdiendo de algo? Cualquier ayuda sería muy apreciada. ¡Gracias por adelantado!

EDITAR: código

IBaseFilter *pSrc = NULL, *pSrc2 = NULL, *pWaveDest = NULL, *pWriter = NULL;
IFileSinkFilter *pSink= NULL;
IGraphBuilder *pGraph;
ICaptureGraphBuilder2 *pBuild;
IMediaControl *pControl = NULL;
// This example omits error handling.

hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC_SERVER,
    IID_ICaptureGraphBuilder2, (void**)&pBuild);

hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void**)&pGraph);
//Initialize the Capture Graph Builder
hr = pBuild->SetFiltergraph(pGraph);

// Not shown: Use the System Device Enumerator to create the 
// audio capture filter.
hr = pMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)&pSrc);
hr = pGraph->AddFilter(pSrc, L"VideooCap");

hr = pMoniker2->BindToObject(0, 0, IID_IBaseFilter, (void**)&pSrc2);
hr = pGraph->AddFilter(pSrc2, L"AudioCap");

IBaseFilter *pMux;
//IFileSinkFilter *pSink;
hr = pBuild->SetOutputFileName(
    &MEDIASUBTYPE_Avi,  // Specifies AVI for the target file.
    L"C:\\wav\\Example2.mp4", // File name.
    &pMux,              // Receives a pointer to the mux.
    NULL);              // (Optional) Receives a pointer to the file sink.

IUnknownPtr pUnk;
//static CLSID const clsid = { 0x025BE2E4, 0x1787, 0x4DA4, { 0xA5,0x85,0xC5,0xB2,0xB9,0xEE,0xB5,0x7C } };

static CLSID const clsid = { 0x5FD85181, 0xE542, 0x4e52, { 0x8D,0x9D,0x5D,0x61,0x3C,0x30,0x13,0x1B } };
//5FD85181-E542-4e52-8D9D5D613C30131B
HRESULT hr = CreateObjectFromPath(TEXT("c:\\filters\\mp4mux.dll"), clsid, &pUnk);
if (SUCCEEDED(hr))
{
    IBaseFilterPtr pFilter = pUnk;
    HRESULT hr = pGraph->AddFilter(pFilter, L"Private Filter");
}

hr = pBuild->RenderStream(
    NULL,//NULL,//&PIN_CATEGORY_CAPTURE, // Pin category.
    NULL,//&MEDIATYPE_Interleaved,//NULL,//&MEDIATYPE_Audio,      // Media type.
    pSrc,                  // Capture filter.
    NULL,                  // Intermediate filter (optional).
    pMux);                 // Mux or file sink filter.

hr = pBuild->RenderStream(
    NULL,//NULL,//&PIN_CATEGORY_CAPTURE, // Pin category.
    NULL,//&MEDIATYPE_Interleaved,//NULL,//&MEDIATYPE_Audio,      // Media type.
    pSrc2,                  // Capture filter.
    NULL,                  // Intermediate filter (optional).
    pMux);                 // Mux or file sink filter.

    IMediaControl *pMC = NULL;
    hr = pGraph->QueryInterface(IID_IMediaControl, (void **)&pMC);
    printf("START");  
    hr = pMC->Run();
    Sleep(4000);
      hr = pMC->Stop();
    printf("END");  
CoUninitialize();
    }
}