anchor.diff:      "--enable-adpcmdec"
       "--enable-adpcmenc"
       "--enable-aiff"
  +    "--enable-videoframe_audiolevel"
       "--enable-asfmux"
       "--enable-audiofxbad"
       "--enable-audiomixer"
  
positive.code:     "--disable-apple_media"
      "--disable-bluez"
      "--disable-avc"
      (enFlag "shm" (xorg.libXext != null) null)
      #--disable-vcd
      #--disable-opensles
      #--disable-uvch264
      (enFlag "assrender" (libass != null) null)
      #(enFlag "voamrwbenc" (vo-amrwbenc != null) null)
      #(enFlag "voaacenc" (vo-aacenc != null) null)
  
negative.code:     (enFlag "gl" (mesa != null) null)
      #(enFlag "gtk3" ( != null) null)
      #(enFlag "qt" ( != null) null)
      #"--disable-vulkan"
      (enFlag "libvisual" (libvisual != null) null)
      #(enFlag "timidity" ( != null) null)
      #(enFlag "teletextdec" ( != null) null)
  