FF_MERGE_MARKER   435 libavcodec/avpacket.c         bytestream_put_be64(&p, FF_MERGE_MARKER);
FF_MERGE_MARKER   447 libavcodec/avpacket.c     if (!pkt->side_data_elems && pkt->size >12 && AV_RB64(pkt->data + pkt->size - 8) == FF_MERGE_MARKER){