anchor.diff:  in
   
   assert openglSupport -> libGLU_combined != null;
  +assert libmfxSupport -> intel-media-sdk != null;
  +assert libaomSupport -> libaom != null;
   
   stdenv.mkDerivation rec {
   
  
positive.code:     bzip2 fontconfig freetype gnutls libiconv lame libass libogg libssh libtheora
      libvdpau libvorbis lzma soxr x264 x265 xvidcore zlib libopus speex nv-codec-headers
    ] ++ optional openglSupport libGLU_combined
      ++ optional vpxSupport libvpx
      ++ optionals (!isDarwin && !isAarch32) [ libpulseaudio ] # Need to be fixed on Darwin and ARM
      ++ optional ((isLinux || isFreeBSD) && !isAarch32) libva
  
negative.code:       (ifMinVer "0.6" (enableFeature vpxSupport "libvpx"))
        (ifMinVer "2.4" "--enable-lzma")
        (ifMinVer "2.2" (enableFeature openglSupport "opengl"))
        (ifMinVer "4.2" (enableFeature libmfxSupport "libmfx"))
        (ifMinVer "4.2" (enableFeature libaomSupport "libaom"))
        (disDarwinOrArmFix (ifMinVer "0.9" "--enable-libpulse") "0.9" "--disable-libpulse")
        (ifMinVer "2.5" (if sdlSupport && reqMin "3.2" then "--enable-sdl2" else if sdlSupport then "--enable-sdl" else null)) # autodetected before 2.5, SDL1 support removed in 3.2 for SDL2
        (ifMinVer "1.2" "--enable-libsoxr")
  