for i in 0..4 {
self.mc_block(i, 0, mb_x * 16 + (i & 1) * 8, mb_y * 16 + (i >> 1) * 8, cur_mv);
dist += sad(&cur_blk[i], &self.ref_blk[i]);
for i in 0..4 {
self.mc_block(i, 0, mb_x * 16 + (i & 1) * 8, mb_y * 16 + (i >> 1) * 8, cur_mv);
dist += sad(&cur_blk[i], &self.ref_blk[i]);