The following code illustrates how to restore motion to an area of the display frozen with MCI_FREEZE.

    MCI_VID_RECT_PARMS mciUnFreezeParms;
    USHORT  usUserParm = 0;
    ULONG   ulReturn;

    /* An example of unfreezing a sub-rectangle */
    memset (&mciUnFreezeParms, 0x00, sizeof (MCI_VID_RECT_PARMS));
    mciUnFreezeParms.hwndCallback = hwndNotify;
    mciUnFreezeParms.rc.xLeft   = lX1;
    mciUnFreezeParms.rc.yBottom = lY1;
    mciUnFreezeParms.rc.xRight  = lX2;
    mciUnFreezeParms.rc.yTop    = lY2;


    ulReturn = mciSendCommand(usDeviceID, MCI_UNFREEZE,
                   MCI_WAIT | MCI_OVLY_FREEZE_RECT,
                   (PVOID)&mciUnFreezeParms,
                  usUserParm);