NB_SCALES          31 libavfilter/avf_ahistogram.c enum DisplayScale   { LINEAR, SQRT, CBRT, LOG, RLOG, NB_SCALES };
NB_SCALES          49 libavfilter/avf_showspectrum.c enum DisplayScale { LINEAR, SQRT, CBRT, LOG, FOURTHRT, FIFTHRT, NB_SCALES };
NB_SCALES          40 libavfilter/vaf_spectrumsynth.c enum MagnitudeScale { LINEAR, LOG, NB_SCALES };
NB_SCALES          63 libavfilter/vf_waveform.c     NB_SCALES