anchor.diff:      #(enFlag "mpeg2enc" ( != null) null)
       (enFlag "mpg123" (mpg123 != null) null)
       #(enFlag "mplex" ( != null) null)
  -    (enFlag "musepack" (libmpcdec != null) null)
  +    (enFlag "musepack" (musepack != null) null)
       #(enFlag "nas" ( != null) null)
       #(enFlag "neon" ( != null) null)
       #(enFlag "ofa" ( != null) null)
  
positive.code: , libbs2b
  , libmms
  , libmodplug
  , libmpcdec
  , libopus
  , librsvg
  , libsndfile
  
negative.code:     libbs2b
      libmms
      libmodplug
      libopus
      librsvg
      libvdpau
  