anchor.diff:  , libcdio
   , libdvdread
   , libmad
  -, mpeg2dec
  +, libmpeg2
   , orc
   , x264
   }:
  
positive.code:     "--enable-realmedia"
      # External plugins
      (enFlag "a52dec" (a52dec != null) null)
      (enFlag "amrnb" (amrnb != null) null)
      (enFlag "amrwb" (amrnb != null) null)
      (enFlag "cdio" (libcdio != null) null)
      (enFlag "dvdread" (libdvdread != null) null)
      (enFlag "lame" (lame != null) null)
      (enFlag "mad" (libmad != null) null)
      (enFlag "mpeg2dec" (mpeg2dec != null) null)
      #(enFlag "sidplay" (sidplay != null) null)
      #(enFlag "twolame" (twolame != null) null)
      (enFlag "x264" (x264 != null) null)
  
negative.code: , python
  
  , a52dec
  #, amrnb
  #, amrwb
  , glib
  , gst-plugins-base
  , gstreamer
  