anchor.diff:  , libvorbis
   , libvpx
   , libwebp
  -, xorg
   , libxcbshmExtlib ? true
   , libxcbxfixesExtlib ? true
   , libxcbshapeExtlib ? true
   , libzimg ? null
  +, mesa_noglu
   , mfx-dispatcher
   , mmal ? null
   , netcdf ? null
  -, nvencExtLib ? false
  -  , nvidia-video-codec-sdk
  +, nvidia-cuda-toolkit
  +, nvidia-video-codec-sdk
   , openal
   #, opencl
   #, opencore-amr
   , opencv
  -, mesa_noglu
   #, openh264
   , openjpeg
  -, opensslExtlib ? false, openssl
  +, openssl
  +, opus
   , pulseaudio_lib
   , rtmpdump
   , rubberband
  
positive.code:      *  Hardware accelerators
       */
      (fflag "--disable-audiotoolbox" "3.1") # darwin
      (fflag "--${boolEn cudaExtLib}-cuda" "3.1")
      /**/(fflag "--disable-cuvid" "3.1")
      "--disable-d3d11va" # windows
      "--disable-dxva2" # windows
  
negative.code: , celt
  #, chromaprint
  #, crystalhd
  , dcadec ? null
  #, decklinkExtlib ? false
  #  , blackmagic-design-desktop-video
  , fdk_aac
  #, flite
  , fontconfig
  , freetype
  