update_volume    3307 fftools/ffplay.c                 update_volume(cur_stream, 1, SDL_VOLUME_STEP);
update_volume    3311 fftools/ffplay.c                 update_volume(cur_stream, -1, SDL_VOLUME_STEP);
update_volume     207 libavfilter/af_compand.c             update_volume(cp, fabs(src[i]));
update_volume     248 libavfilter/af_compand.c             update_volume(cp, fabs(in));
update_volume     547 libavfilter/af_mcompand.c         update_volume(l, fabs(ibuf[i]), ch);