Enca package now has new upstream, you might want to include newly released version and update links to website. You can find downloads at <http://dl.cihar.com/enca/>, as website is currently used <http://gitorious.org/enca>. If your package contained any patches for enca, feel free to send them to me so that I can merge it in next release.
Thanks, successfully built in rawhide: http://kojipkgs.fedoraproject.org/packages/enca/1.10/1.fc12/