SetAlphaBitmap not working

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...

Code:

// 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....

Code:

//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; }