if(!(IS_FIL (h->mtype))) return;
void ff_h261_loop_filter(H261Context * h){    MpegEncContext * const s = &h->s;    const int linesize  = s->linesize;    const int uvlinesize= s->uvlinesize;    uint8_t *dest_y = s->dest[0];    uint8_t *dest_cb= s->dest[1];    uint8_t *dest_cr= s->dest[2];        s->dsp.h261_loop_filter(dest_y                   , linesize);    s->dsp.h261_loop_filter(dest_y                + 8, linesize);    s->dsp.h261_loop_filter(dest_y + 8 * linesize    , linesize);    s->dsp.h261_loop_filter(dest_y + 8 * linesize + 8, linesize);    s->dsp.h261_loop_filter(dest_cb, uvlinesize);    s->dsp.h261_loop_filter(dest_cr, uvlinesize);}