The following code illustrates how to set the source and destination rectangle arrays for the transformation of the video.

  MCI_DGV_RECT_PARMS mciRectParms;
  USHORT  usUserParm = 0;
  ULONG   ulReturn;

  /* An example of changing the SOURCE area to a
     sub-rectangle of the total input */
  memset (&mciRectParms, 0x00, sizeof (MCI_DGV_RECT_PARMS));
  mciRectParms.hwndCallback = hwndNotify;
  mciRectParms.rc.xLeft   = lX1;
  mciRectParms.rc.yBottom = lY1;
  mciRectParms.rc.xRight  = lX2;
  mciRectParms.rc.yTop    = lY2;


  ulReturn = mciSendCommand(usDeviceID, MCI_PUT,
                 MCI_WAIT | MCI_DGV_PUT_RECT |
                 MCI_DGV_RECORD | MCI_DGV_PUT_SOURCE,
                 (PVOID)&mciRectParms,
                 usUserParm);