anchor.diff:  
     buildInputs = [
       bzip2 fontconfig freetype gnutls libiconv lame libass libogg libssh libtheora
  -    libvorbis xz soxr x264 x265 xvidcore zlib libopus speex nv-codec-headers
  +    libvorbis xz soxr x264 x265 xvidcore zlib libopus speex srt nv-codec-headers
     ] ++ optionals openglSupport [ libGL libGLU ]
       ++ optional libmfxSupport intel-media-sdk
       ++ optional libaomSupport libaom
  
positive.code:     # Build flags
        "--enable-shared"
        (ifMinVer "0.6" "--enable-pic")
        (enableFeature runtimeCpuDetectBuild "runtime-cpudetect")
        "--enable-hardcoded-tables"
      ] ++
  
negative.code: , alsaLib, bzip2, fontconfig, freetype, gnutls, libiconv, lame, libass, libogg
  , libssh, libtheora, libva, libdrm, libvorbis, libvpx, xz, libpulseaudio, soxr
  , x264, x265, xvidcore, zlib, libopus, speex, nv-codec-headers, dav1d
  , srt ? null
  , openglSupport ? false, libGLU ? null, libGL ? null
  , libmfxSupport ? false, intel-media-sdk ? null
  , libaomSupport ? false, libaom ? null
  