anchor.diff:      ++ stdenv.lib.optional xvidSupport xvidcore
       ++ stdenv.lib.optional faacSupport faac;
   
  +  enableParallelBuilding = true;
  +    
     crossAttrs = {
       dontSetConfigureCross = true;
       configureFlags = configureFlags ++ [
  
positive.code: assert xvidSupport -> xvidcore != null;
  
  stdenv.mkDerivation rec {
    name = "ffmpeg-0.7-rc1";
    
    src = fetchurl {
      url = "http://www.ffmpeg.org/releases/${name}.tar.bz2";
      sha256 = "07ma2b80nslwwy4ddfrz8k575dxyc8x9mvja55ghrwxys8lkhw2m";
    };
    
    # `--enable-gpl' (as well as the `postproc' and `swscale') mean that
  
negative.code: , mp3Support ? true, lame ? null
  , speexSupport ? true, speex ? null
  , theoraSupport ? true, libtheora ? null
  , vorbisSupport ? false, libvorbis ? null
  , vpxSupport ? false, libvpx ? null
  , x264Support ? true, x264 ? null
  , xvidSupport ? false, xvidcore ? null
  , faacSupport ? false, faac ? null
  }:
  
  