int pix_abs16x16_y2_c(UINT8 *blk1, UINT8 *blk2, int lx, int h);
int pix_abs16x16_xy2_c(UINT8 *blk1, UINT8 *blk2, int lx, int h);
int pix_abs16x16_y2_c(UINT8 *blk1, UINT8 *blk2, int lx, int h);
int pix_abs16x16_xy2_c(UINT8 *blk1, UINT8 *blk2, int lx, int h);