Fedora Core4 comes with little multimedia support by default. Read this http://www.fedorafaq.org
for info, unfortunately, that requires your Linux machine to be connected to the Internet. You can, of course, use this site http://www.pbone.net
to get your Fedora RPMs downloaded such as Realplayer and Xine but it won't be able to fetch dependencies this way so you will have to get them yourself!!