Using Camera with DirectShow in Windows Mobile

Headman · wrote on 15 Mar 2011, 11:34

Has anybody experience with this?

I used the CodeExample from Microsofts WM SDK, included all libs and call the functions in my own code in the same order. No Compiling error but it doesn´t work.

andre · wrote on 15 Mar 2011, 11:38

"It doesn't work" is way too vague to give any meaningful answer to.

tobias.hunger · wrote on 15 Mar 2011, 12:56

How is this Qt related?

Headman · wrote on 15 Mar 2011, 13:05

The CodeExample:
Windows Mobile 6 SDK\Samples\PocketPC\CPP\win32\CameraCapture

I included graphmanager.cpp and cpropertybag.cpp (and Headers) into my QT-Project.

In my QDialog i´ve a frame where I want to show the Preview of the Camera, todo this i included the code from the Example in a function called InitializeGraph()

@
bool Beladezustand::InitializeGraph()
{

HRESULT hr;
    wchar_t szDevicename[MAX_PATH] = L"\0";
    CPropertyBag PropBag;
    CComVariant varCamName;
    CComPtr<IGraphBuilder> pFilterGraph;
        CComPtr<ICaptureGraphBuilder2> pCaptureGraphBuilder;
        CComPtr<IBaseFilter> pVideoCaptureFilter;
        CComPtr<IPersistPropertyBag> pPropertyBag;
    CComPtr<IMediaControl> pMediaControl;
        IVideoWindow *pVidWin;

        //Capture Graph anlegen
        hr = CoCreateInstance(CLSID_CaptureGraphBuilder, NULL, CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2, (void **)&pCaptureGraphBuilder);
    hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,IID_IGraphBuilder, (void **)&pFilterGraph);
    hr = pCaptureGraphBuilder->SetFiltergraph( pFilterGraph );
        //Media Control abrufen
        hr = pFilterGraph->QueryInterface(IID_IMediaControl,(void **)&pMediaControl);
    //Video Window abrufen
        hr = pFilterGraph->QueryInterface(IID_IVideoWindow,(void **)&pVidWin);
    //Capture Filter anlegen
        hr = CoCreateInstance(CLSID_VideoCapture, NULL, CLSCTX_INPROC,IID_IBaseFilter, (void**)&pVideoCaptureFilter);
    //IPersistPropertyBag abrufen
        hr = pVideoCaptureFilter->QueryInterface( &pPropertyBag );
        //Kamera laden
    GetFirstCameraDriver(szDevicename);
    varCamName = szDevicename;
    hr = PropBag.Write( L"VCapName", &varCamName );
    hr = pPropertyBag->Load( &PropBag, NULL );
    hr = pFilterGraph->AddFilter( pVideoCaptureFilter, L"Video Capture Filter Source" );
   
    //Mit dem Preview PIN verbinden
        hr = pCaptureGraphBuilder->RenderStream(&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video, pVideoCaptureFilter, NULL, NULL);
        //Das Preview Fenster setzen

// CRect rc;
// ::GetClientRect(m_hWnd,&rc);

        hr = pVidWin->put_Owner((OAHWND)frame->winId());               //<-- QT Frame where i want to show the Camera-Preview in

    hr = pVidWin->put_WindowStyle(WS_CHILD | WS_CLIPSIBLINGS);
    long pWidth, pHeight;
    hr = pVidWin->get_Width(&pWidth);
    hr = pVidWin->get_Height(&pHeight);
        hr = pVidWin->put_Height(215);
        hr = pVidWin->put_Width(162);
    //hr = pVidWin->SetWindowPosition(0,0,162,215);
    //Den Stream abspielen (Preview anzeigen)
        hr = pMediaControl->Run();

}
@

I just wonder why the CodeExample from MS works and why not in my Qt-Project. Perhaps it works but the the delivered frame->winId() does not work for the MS functions...

EDIT: please sorround code by @-tags, Gerolf

andre · wrote on 15 Mar 2011, 13:14

Are you using the same compiler as the libs you link against?

Headman · wrote on 15 Mar 2011, 13:59

Hm, I compiled the CodeExample with VisualStudio 2008, my QT Projekt with QTCreator 1.3.0 (Qt 4.6.0) using nmake.exe (which is VS2008 or not?)

andre · wrote on 15 Mar 2011, 16:15

[quote author="Headman" date="1300197594"]Hm, I compiled the CodeExample with VisualStudio 2008, my QT Projekt with QTCreator 1.3.0 (Qt 4.6.0) using nmake.exe (which is VS2008 or not?)[/quote]
And your Qt libs are compiled with that as well, are they not?

Headman · wrote on 16 Mar 2011, 09:29

sure, they are

andre · wrote on 16 Mar 2011, 09:45

I have no experience with debugging on windows mobile. Is there a way to get some debug output when trying to start the application? Does that yield anything?

Are you sure all your libraries and your application are in the same compile mode (debug or release)? I am just giving some suggestions on what might be wrong here...