update_volume    1514 fftools/ffplay.c static void update_volume(VideoState *is, int sign, double step)
update_volume     144 libavfilter/af_compand.c static void update_volume(ChanParam *cp, double in)
update_volume     167 libavfilter/af_mcompand.c static void update_volume(CompBand *cb, double in, int ch)