anchor.diff:  , youtubeSupport     ? true,  youtube-dl    ? null
   , vaapiSupport       ? true,  libva         ? null
   , drmSupport         ? true,  libdrm        ? null
  +, openalSupport      ? true,  openalSoft   ? null
   , vapoursynthSupport ? false, vapoursynth   ? null
   , archiveSupport     ? false, libarchive    ? null
   , jackaudioSupport   ? false, libjack2      ? null
  
positive.code:     ++ optional vdpauSupport       libvdpau
      ++ optional speexSupport       speex
      ++ optional bs2bSupport        libbs2b
      ++ optional libpngSupport      libpng
      ++ optional youtubeSupport     youtube-dl
      ++ optional sdl2Support        SDL2
  
negative.code:     (enableFeature archiveSupport "libarchive")
      (enableFeature dvdreadSupport "dvdread")
      (enableFeature dvdnavSupport "dvdnav")
      (enableFeature openalSupport "openal")
      (enableFeature vaapiSupport "vaapi")
      (enableFeature waylandSupport "wayland")
      (enableFeature stdenv.isLinux "dvbin")
  