if(val > 16)
if(val > 15)
static void h261_encode_motion(H261Context * h, int val){    MpegEncContext * const s = &h->s;    int sign, code;    if(val==0){        code = 0;        put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);    }     else{        if(val > 16)            val -=32;        if(val < -16)            val+=32;        sign = val < 0;        code = sign ? -val : val;         put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);        put_bits(&s->pb,1,sign);    }}