[Imtoolkit-users] im_capture doubt

[cykt <cy...@aj...>]

Hi,

 

I’m trying to use im_capture library in order to capture one frame from USB
2.0 webcam (640x480 resolution).

I have followed capture guide basic program exactly the same way is written
in the document. I  mean:

 

      void capturaCamera(unsigned char *pImage)

      {

            imVideoCapture* vc = imVideoCaptureCreate();

            if (vc == NULL)

                  printf ("\nCreation error");

 

            if (!imVideoCaptureConnect(vc, 0)){

                  printf ("\nConnection Error");

 

            }

            int width=0, height=0;

            imVideoCaptureGetImageSize(vc, &width, &height);

 

printf ("\n width = %d, height = %d", width, height );

 

            if (!imVideoCaptureOneFrame(vc, pImage, 1))

                  printf ("\nCapture Error");

 

            imVideoCaptureDisconnect(vc);

            imVideoCaptureDestroy(vc);

                }

 

It works until imVideoCaptureOneFrame() procedure. But here, it returns a
NULL value.

I’m using Windows Vista Home, Eclipse CDT, MingW 3.4.5. The program  is
written in C language.

 

I have already tested imVideoCaptureLive() and imVideoCaptureFrame()
functions, but the results was the same.

Also, I have tested imVideoCaptureReloadDevices(), aiming to clear device,
but no result.

 

I have tested webcam using the following  applications: AMcap and ÑAUSA
(which uses im library). And it works well.

 

What is wrong ?

 

 

Thanks in advance

 

Luiz