*range = 8 * (1 << (f_code - 1));  if (s->out_format == FMT_H263 && !s->h263_msmpeg4) *range *= 2;
if(s->avctx->me_range) *range= s->avctx->me_range >> 1; else                   *range= 16;
static inline void get_limits(MpegEncContext *s, int *range, int *xmin, int *ymin, int *xmax, int *ymax, int f_code){    *range = 8 * (1 << (f_code - 1));    /* XXX: temporary kludge to avoid overflow for msmpeg4 */    if (s->out_format == FMT_H263 && !s->h263_msmpeg4)	*range *= 2;    if (s->unrestricted_mv) {        *xmin = -16;        *ymin = -16;        if (s->h263_plus)            *range *= 2;        if(s->avctx->codec->id!=CODEC_ID_MPEG4){            *xmax = s->mb_width*16;            *ymax = s->mb_height*16;        }else {            *xmax = s->width;            *ymax = s->height;        }    } else {        *xmin = 0;        *ymin = 0;        *xmax = s->mb_width*16 - 16;        *ymax = s->mb_height*16 - 16;    }}