anchor.diff:   *
    * Not packaged:
    *   aacplus avisynth cdio-paranoia crystalhd libavc1394 libiec61883
  - *   libnut libquvi nvenc opencl oss shine twolame
  + *   libnut libquvi nvenc oss shine twolame
    *   utvideo vo-aacenc vo-amrwbenc xvmc zvbi blackmagic-design-desktop-video
    *
    * Need fixes to support Darwin:
  
positive.code:     (enableFeature (xz != null) "lzma")
      (enableFeature nvenc "nvenc")
      (enableFeature (openal != null) "openal")
      #(enableFeature opencl "opencl")
      (enableFeature (opencore-amr != null && version3Licensing) "libopencore-amrnb")
      #(enableFeature (opencv != null) "libopencv")
      (enableFeature openglExtlib "opengl")
  
negative.code:     bzip2 celt dav1d fontconfig freetype frei0r fribidi game-music-emu gnutls gsm
      libjack2 ladspaH lame libaom libass libbluray libbs2b libcaca libdc1394 libmodplug libmysofa
      libogg libopus librsvg libssh libtheora libvdpau libvorbis libvpx libwebp libX11
      libxcb libXv libXext libxml2 xz openal ocl-icd opencl-headers openjpeg libpulseaudio rav1e svt-av1 rtmpdump opencore-amr
      samba SDL2 soxr speex srt vid-stab vo-amrwbenc x264 x265 xavs xvidcore
      zeromq4 zimg zlib openh264
    ] ++ optionals openglExtlib [ libGL libGLU ]
  