anchor.diff:  { lib
   , stdenv
   , fetchurl
  -, fetchpatch
   , aalib
   , alsaLib
   , ffmpeg
  
positive.code: , libtheora
  , libv4l
  , libvorbis
  , perl
  , pkg-config
  , speex
  
negative.code:     libtheora
      libv4l
      libvorbis
      ncurses
      perl
      speex
      vcdimager
  