clamp_mv(mv, xd->mb_to_left_edge - LEFT_TOP_MARGIN,
xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN,
xd->mb_to_top_edge - LEFT_TOP_MARGIN,
clamp_mv(mv, xd->mb_to_left_edge - LEFT_TOP_MARGIN,
xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN,
xd->mb_to_top_edge - LEFT_TOP_MARGIN,