Here is the solution, if you want the easy way out.
download apt-get at
http://apt.freshrpms.net and then after apt is installed you should type the following things in console as root
apt-get update
and then type
apt-get install mplayer
APT-GET is a program that automatically looks for and fetches the RPMs for a program and then will install them for you.
This is better because the apt get also fetches all the divx codecs and such and installs them too. Megaman taught me about apt-get.
It can also install a lot of other stuff too.... before you go looking for RPMs on something just try apt-get install programname
also apt-get update packagename will update a program
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freshrpms.net has the apt for red hat linux and yellow dog linux.... if you're not using one of those, I don't know what you can do.
I hear apt is available for SuSe too. Apt is on debian of course, because thats where it was invented