anchor.diff:      opencv3
       openexr
       openh264
  +    rtmpdump
       pango
       sbc
       soundtouch
  
positive.code:     "-Dopenmpt=disabled" # `libopenmpt` not packaged in nixpkgs as of writing
      "-Dopenni2=disabled" # not packaged in nixpkgs as of writing
      "-Dopensles=disabled" # not packaged in nixpkgs as of writing
      "-Drtmp=disabled" # `librtmp` not packaged in nixpkgs as of writing
      "-Dsctp=disabled" # required `usrsctp` library not packaged in nixpkgs as of writing
      "-Dteletext=disabled" # required `zvbi` library not packaged in nixpkgs as of writing
      "-Dtinyalsa=disabled" # not packaged in nixpkgs as of writing
  
negative.code: , openexr
  , openh264
  , pango
  , rtmpdump
  , sbc
  , soundtouch
  , spandsp
  