fprintf(stderr, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);
av_log(s->avctx, AV_LOG_ERROR, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);
static int msmpeg4_decode_motion(MpegEncContext * s,                                  int *mx_ptr, int *my_ptr){    MVTable *mv;    int code, mx, my;    mv = &mv_tables[s->mv_table_index];    code = get_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2);    if (code < 0){        fprintf(stderr, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);        return -1;    }    if (code == mv->n) {//printf("MV ESC %X at %d %d\n", show_bits(&s->gb, 24), s->mb_x, s->mb_y);        mx = get_bits(&s->gb, 6);        my = get_bits(&s->gb, 6);    } else {        mx = mv->table_mvx[code];        my = mv->table_mvy[code];    }    mx += *mx_ptr - 32;    my += *my_ptr - 32;    /* WARNING : they do not do exactly modulo encoding */    if (mx <= -64)        mx += 64;    else if (mx >= 64)        mx -= 64;    if (my <= -64)        my += 64;    else if (my >= 64)        my -= 64;    *mx_ptr = mx;    *my_ptr = my;    return 0;}