SetAlphaBitmap not working

[12oclocker]

I'm using directshow, using VMR-7 IVMRWindowlessControl video..
I can't get SetAlphaBitmap to work.
SetAlphaBitmap returns S_OK, and acts like a bitmap was set on the video, but I see nothing.

Anyone have any ideas?

code snip 1...

    // Set the rendering mode and number of streams.
    IVMRFilterConfig* pConfig;
    hr = m_pVmr->QueryInterface(IID_IVMRFilterConfig, (void**)&pConfig);
    if(FAILED(hr))
    {
        TRACE("\nFailed to get IVMRFilterConfig interface");
        CloseInterfaces();
        return FALSE;
    }
    pConfig->SetRenderingMode(VMRMode_Windowless);
    pConfig->SetNumberOfStreams(2);//must do this for VMR-7 to overlay a Bitmap image
    SAFE_RELEASE(pConfig);

now the alpha overlay function, which does not work for me....

//load test bitmap...
HBITMAP hBmp = LoadBitmap(GetModuleHandle(NULL), MAKEINTRESOURCE(IDR_VMR));
//HWND of video window
HRESULT video::BlendImage2(HWND hWnd, HBITMAP hbm)
{
    IVMRWindowlessControl* pWc = m_pWc;

    LONG cx, cy;
    HRESULT hr;
    hr = pWc->GetNativeVideoSize(&cx, &cy, NULL, NULL);
    if(FAILED(hr))
    { return hr; }

    HDC hdc = GetDC(hWnd);
    if(hdc == NULL)
    { return E_FAIL; }

    HDC hdcBmp = CreateCompatibleDC(hdc);
    ReleaseDC(hWnd,hdc);
    if(hdcBmp == NULL)
    { return E_FAIL; }

    BITMAP bm;
    if (0 == GetObject(hbm,sizeof(bm),&bm))
    { DeleteDC(hdcBmp); return E_FAIL; }

    HBITMAP hbmOld = (HBITMAP)SelectObject(hdcBmp, hbm);
    if (hbmOld == 0)
    { DeleteDC(hdcBmp); return E_FAIL; }

    VMRALPHABITMAP bmpInfo;
    ZeroMemory(&bmpInfo, sizeof(bmpInfo) );
    bmpInfo.dwFlags = VMRBITMAP_HDC;
    bmpInfo.hdc = hdcBmp;

    // Show the entire bitmap in the top-left corner of the video image.
    SetRect(&bmpInfo.rSrc, 0, 0, bm.bmWidth, bm.bmHeight);
    bmpInfo.rDest.left = 0.f;
    bmpInfo.rDest.top = 0.f;
    bmpInfo.rDest.right = 1.0;//(float)bm.bmWidth / (float)cx;
    bmpInfo.rDest.bottom = 1.0;//(float)bm.bmHeight / (float)cy;
    bmpInfo.fAlpha = 1.0f;// Set the transparency value (1.0 is opaque, 0.0 is transparent).

    IVMRMixerBitmap* pBmp;
    hr = pWc->QueryInterface(IID_IVMRMixerBitmap,(LPVOID*)&pBmp);
    if (SUCCEEDED(hr))
    {
        pBmp->SetAlphaBitmap(&bmpInfo);
        pBmp->Release();
    }

    DeleteObject(SelectObject(hdcBmp,hbmOld));
    DeleteDC(hdcBmp);
    return hr;
}