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); } }