anchor.diff:      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 xz openal openjpeg libpulseaudio rav1e svt-av1 rtmpdump opencore-amr
  +    libxcb libXv libXext libxml2 xz openal openjpeg libpulseaudio rav1e svt-av1 rtmpdump opencore-amr
       samba SDL2 soxr speex srt vid-stab vo-amrwbenc x264 x265 xavs xvidcore
       zeromq4 zimg zlib
     ] ++ optionals openglExtlib [ libGL libGLU ]
  
positive.code:     (enableFeature libxcbshmExtlib "libxcb-shm")
      (enableFeature libxcbxfixesExtlib "libxcb-xfixes")
      (enableFeature libxcbshapeExtlib "libxcb-shape")
      (enableFeature (xz != null) "lzma")
      (enableFeature nvenc "nvenc")
      (enableFeature (openal != null) "openal")
  
negative.code: , libxcbshapeExtlib ? true # X11 grabbing shape rendering
  , libXv ? null # Xlib support
  , libXext ? null # Xlib support
  , libxml2 ? null # libxml2 support, for IMF and DASH demuxers
  , xz ? null # xz-utils
  , nvenc ? !stdenv.isDarwin && !stdenv.isAarch64, nv-codec-headers ? null # NVIDIA NVENC support
  , openal ? null # OpenAL 1.1 capture support
  