if (s->mb_y == 0 || s->first_slice_line || s->first_gob_line) {
if ((s->mb_y == 0 || s->first_slice_line || s->first_gob_line) && block<2) {
INT16 *h263_pred_motion(MpegEncContext * s, int block,                         int *px, int *py){    int xy, wrap;    INT16 *A, *B, *C, *mot_val;    static const int off[4]= {2, 1, 1, -1};    wrap = s->block_wrap[0];    xy = s->block_index[block];    mot_val = s->motion_val[xy];    /* special case for first line */    if (s->mb_y == 0 || s->first_slice_line || s->first_gob_line) {        A = s->motion_val[xy - 1];        *px = A[0];        *py = A[1];    } else {        A = s->motion_val[xy - 1];        B = s->motion_val[xy - wrap];        C = s->motion_val[xy + off[block] - wrap];        *px = mid_pred(A[0], B[0], C[0]);        *py = mid_pred(A[1], B[1], C[1]);    }    return mot_val;}