s->gob_number = mb_line;
s->gob_number = mb_line / s->gob_index;
int h263_encode_gob_header(MpegEncContext * s, int mb_line){    int pdif=0;        /* Check to see if we need to put a new GBSC */    /* for RTP packetization                    */    if (s->rtp_mode) {        pdif = s->pb.buf_ptr - s->ptr_lastgob;        if (pdif >= s->rtp_payload_size) {            /* Bad luck, packet must be cut before */            align_put_bits(&s->pb);            s->ptr_lastgob = s->pb.buf_ptr;            put_bits(&s->pb, 17, 1); /* GBSC */            s->gob_number = mb_line;            put_bits(&s->pb, 5, s->gob_number); /* GN */            put_bits(&s->pb, 2, 1); /* GFID */            put_bits(&s->pb, 5, s->qscale); /* GQUANT */            return pdif;       } else if (pdif + s->mb_line_avgsize >= s->rtp_payload_size) {           /* Cut the packet before we can't */           align_put_bits(&s->pb);           s->ptr_lastgob = s->pb.buf_ptr;           put_bits(&s->pb, 17, 1); /* GBSC */           s->gob_number = mb_line;           put_bits(&s->pb, 5, s->gob_number); /* GN */           put_bits(&s->pb, 2, 1); /* GFID */           put_bits(&s->pb, 5, s->qscale); /* GQUANT */           return pdif;       }   }   return 0;}