anchor.diff:      ++ stdenv.lib.optional x264Support "--enable-libx264"
       ++ stdenv.lib.optional xvidSupport "--enable-libxvid"
       ++ stdenv.lib.optional vdpauSupport "--enable-vdpau"
  -    ++ stdenv.lib.optional faacSupport "--enable-libfaac --enable-nonfree";
  +    ++ stdenv.lib.optional faacSupport "--enable-libfaac --enable-nonfree"
  +    ++ stdenv.lib.optional dc1394Support "--enable-libdc1394";
   
     buildInputs = [ pkgconfig lame yasm zlib bzip2 ]
       ++ stdenv.lib.optional mp3Support lame
  
positive.code:     ++ stdenv.lib.optional x264Support x264
      ++ stdenv.lib.optional xvidSupport xvidcore
      ++ stdenv.lib.optional vdpauSupport libvdpau
      ++ stdenv.lib.optional faacSupport faac;
  
    enableParallelBuilding = true;
      
  
negative.code: , xvidSupport ? true, xvidcore ? null
  , vdpauSupport ? true, libvdpau ? null
  , faacSupport ? false, faac ? null
  , dc1394Support ? false, libdc1394 ? null
  }:
  
  assert speexSupport -> speex != null;
  