It should compile easily on Redhat if you have the requirements. In fact, I would always recommend compiling mplayer. Of all applications I've tried around, mplayer is the one that truly makes a diffence in terms of performance when compiled.
Still, if you are going for the binaries, I think your best bet is to install apt-get for Redhat 9:
it's an awesome tool that you should have installed, not only for mplayer. Once installed, simply type:
apt-get install mplayer
apt-get will then connect to a mirror, download all packages, including codecs and dependencies and install mplayer for you. Works the same way with over 10k programs.