anchor.diff:  , fdk_aac
   , flite
   , gsm
  +, json-glib
   , libaom
   , libdc1394
   , libde265
  
positive.code:     "-Dwasapi2=disabled" # not packaged in nixpkgs as of writing / no Windows support
      "-Dwpe=disabled" # required `wpe-webkit` library not packaged in nixpkgs as of writing
      "-Dzxing=disabled" # required `zxing-cpp` library not packaged in nixpkgs as of writing
    ]
    ++ lib.optionals (!stdenv.isLinux) [
      "-Dva=disabled" # see comment on `libva` in `buildInputs`
  
negative.code:     orc # for orcc
      python3
      gettext
      gstreamer # for gst-tester-1.0
      gobject-introspection
    ] ++ lib.optionals stdenv.isLinux [
      wayland # for wayland-scanner
  