DIFFELEM_SIZE     170 libavfilter/vf_signature.c     uint64_t conflist[DIFFELEM_SIZE];
DIFFELEM_SIZE     320 libavfilter/vf_signature.c     qsort(conflist, DIFFELEM_SIZE, sizeof(uint64_t), (void*) cmp);
DIFFELEM_SIZE     321 libavfilter/vf_signature.c     fs->confidence = FFMIN(conflist[DIFFELEM_SIZE/2], 255);