Caveat: When you start installing audio-video software it's like pulling a loose
thread on your sleeve. The dependencies explode into a rather large tree.
These days it's easier to install YUM and use it:
yum install mplayer
Yum will chase down the dependencies and make a list of them, then ask if it's OK to download and install all that slop. Say "yes" and it will.
If mplayer isn't available from the standard archives, update the yum repository list to go to the DAG repository. The Red Hat/Fedora crew are rather conservative when it comes to supplying apps which contain proprietary resources (especially MP3 playing capabilities), so their RPM repositories aren't always sufficient.