anchor.diff:        "--enable-libtheora"
         (ifMinVer "2.1" "--enable-libssh")
         (ifMinVer "0.6" (enableFeature vaapiSupport "vaapi"))
  +      (ifMinVer "3.4" (enableFeature vaapiSupport "libdrm"))
         "--enable-vdpau"
         "--enable-libvorbis"
         (ifMinVer "0.6" (enableFeature vpxSupport "libvpx"))
  
positive.code:     ++ optional vpxSupport libvpx
      ++ optionals (!isDarwin && !isAarch32) [ libpulseaudio ] # Need to be fixed on Darwin and ARM
      ++ optional ((isLinux || isFreeBSD) && !isAarch32) libva
      ++ optional isLinux alsaLib
      ++ optionals isDarwin darwinFrameworks
      ++ optional vdpauSupport libvdpau
  
negative.code: { stdenv, fetchurl, pkgconfig, perl, texinfo, yasm
  , alsaLib, bzip2, fontconfig, freetype, gnutls, libiconv, lame, libass, libogg
  , libssh, libtheora, libva, libdrm, libvorbis, libvpx, lzma, libpulseaudio, soxr
  , x264, x265, xvidcore, zlib, libopus, speex
  , openglSupport ? false, libGLU_combined ? null
  # Build options
  