If you still can't find those repositories, you could install (or rather copy) the codecs manually. Another alternative is using VLC, I've never used it myself, but I heard it plays nearly everything without having to install any codec by yourself. But if you insist in installing the codecs manually, then read on.
In the first place, I've never used Suse so I don't know if this method will work for you. However, I know that the following works well at least for Debian and Arch Linux since it's quite a general method. Second, keep in mind that with these instructions you'll be making small changes as root, there shouldn't be any ugly surprises, but I feel I should warn you just in case.
Ok then, download the codec package from the following link
Choose wherever you want to save the compressed file. And from the terminal 'cd' into there.
Then, unpack the file that you've just downloaded with the following command:
tar xvvjf essential-20061022.tar.bz2
note that the last argument is the name of the file you've just downloaded. Now as root
do the following:
And then as root
again, copy all the contents of the 'essential-20061022' directory to the /usr/lib/win32. That's accomplished with:
cp essential-20061022/* /usr/lib/win32
Done! you should be good to go. Just launch either mplayer or xine and you should be able to play most, if not all, of the popular multimedia formats.