Question

AMcap is a app for capturing video or to preview from webcam. Its source code comes with Microsoft Windows SDK as sample.

I want to (bypass the following process of user interaction in amcap code or say want to) set it as default:

Ampcap menu

  Options

    Video Capture Pin ...

        Color Space/Compression: YUY2

        Output size: 1600x1200

I have a compatible webcam and works fine on changing manually to YUY2 and 1600×1200 in AMcap app.

By default it is:

    Color Space/Compression: MJPG

    Output size: 160x120

I tried to find ‘YUY2’ string in whole project, but I could not find it, so that I could hardcode it. It seems it is created dynamically and then operated; refer: in the file amcap.cpp nearby line no 3395.

Answer 1

Hey @Dani van der Meer: Thanks for the Pointer … I have done it by:
In the function BOOL InitCapFilters()

after

 if(hr != NOERROR)
{

    hr = gcap.pBuilder->FindInterface(&PIN_CATEGORY_CAPTURE,
                                      &MEDIATYPE_Video, gcap.pVCap,
                                      IID_IAMStreamConfig, (void **)&gcap.pVSC);

    if(hr != NOERROR)
    {
        // this means we can't set frame rate (non-DV only)
        ErrMsg(TEXT("Error %x: Cannot find VCapture:IAMStreamConfig"), hr);
    }
}

gcap.fCapAudioIsRelevant = TRUE;

Paste:

CMediaType *pmt;
// default capture format
if(gcap.pVSC && gcap.pVSC->GetFormat((AM_MEDIA_TYPE**)&pmt) == S_OK)
{
    // DV capture does not use a VIDEOINFOHEADER
    if(pmt->formattype == FORMAT_VideoInfo)
    {
     pmt->SetType(&MEDIATYPE_Video);
     pmt->SetFormatType(&FORMAT_VideoInfo);
     pmt->SetSubtype(&MEDIASUBTYPE_YUY2);
     pmt->SetTemporalCompression(FALSE);

     VIDEOINFOHEADER* lpvihin = (VIDEOINFOHEADER*) pmt->pbFormat;

        {

             //DWORD fccYUY2 =  'YUY2' ;
             //lpvihin->bmiHeader.biCompression  =fccYUY2;
            //'YUY2';// MAKEFOURCC('Y','U','Y','2');
            //lpvihin->bmiHeader.biBitCount = 16; 
            lpvihin->bmiHeader.biWidth =  1600;// 960; //1600;
            lpvihin->bmiHeader.biHeight =  1200;//  720; //1200;
            lpvihin->bmiHeader.biSizeImage =   1600*1200*3; 

            hr = gcap.pVSC->SetFormat(pmt);

            ResizeWindow(HEADER(pmt->pbFormat)->biWidth,
                     ABS(HEADER(pmt->pbFormat)->biHeight));
        }
    }
    if(pmt->majortype != MEDIATYPE_Video)
    {
        // This capture filter captures something other that pure video.
        // Maybe it's DV or something?  Anyway, chances are we shouldn't
        // allow capturing audio separately, since our video capture
        // filter may have audio combined in it already!
        gcap.fCapAudioIsRelevant = FALSE;
        gcap.fCapAudio = FALSE;
    }
    DeleteMediaType(pmt);
}

Thanks a lot