PTS_STEP         1191 libavfilter/avf_showcqt.c         s->next_pts += PTS_STEP;
PTS_STEP         1367 libavfilter/avf_showcqt.c     outlink->time_base = av_mul_q(av_inv_q(s->rate), av_make_q(1, PTS_STEP));
PTS_STEP         1535 libavfilter/avf_showcqt.c                     s->next_pts = pts + PTS_STEP;