# web example:
#   af=dynaudnorm=p=0.71:m=100:s=12:g=15
#   g = gausssize  (31 is default, must be odd)
#   p = peak       (0.95)
#   m = maxgain    (10)
#   s = compress   (0)
# these doesn't seem to do anything:
#   ad-lavc-ac3drc=6
#   audio-normalize-downmix