The following example is a simple frame callback function. Register this callback by using the capSetCallbackOnFrame macro.
// FrameCallbackProc: frame callback function
// hWnd: capture window handle
// lpVHdr: pointer to struct containing captured
// frame information
//
LRESULT PASCAL FrameCallbackProc(HWND hWnd, LPVIDEOHDR lpVHdr)
{
if (!ghWndMain)
return FALSE;
wsprintf(gachBuffer, "Preview frame# %ld ", gdwFrameNum++);
SetWindowText(ghWndMain, (LPSTR)gachBuffer);
return (LRESULT) TRUE ;
}