I doubt there is a single format that Mplayer cannot play once it has 
the necessary codecs installed. The solution to your problem might just 
be a simple matter of getting the Real media codecs installed for 
Mplayer. And then, Mplayer plugin will be your single solution for all 
your media needs.

I don't use repositories like dag, and build programs like Mplayer from 
source. So I don't know what codecs those rpm packages come with. But if 
you just go the more basic route, you can get "codec packs" from 
Mplayer's website, which will surely do anything any normal person will 
ever need.
[ http://www.mplayerhq.hu/homepage/design7/dload.html ]

All you need to do is to download the ones you need and move them to 
your Mplayer plugins folder.

Harish

Benjamin Sher wrote:

>Dear Troy:
>
>I would appreciate your advice on RealPlayer. I recall from the article I read 
>yesterday on Yum that the author specifically advised users of yum never to 
>install any rpm the old fashioned way in /usr/local/. Unfortunately, since I 
>am a Russian translator, I need RealPlayer to play my Russian stations. I 
>thought Helix could do it, but it does not play any proprietary formats like 
>ra and rm. Only RealPlayer can play their own formats. Here is the URL for 
>the page listing the RealPlayer rpm for RHEL 4 (right after the list for 
>Helix):
>
>https://helixcommunity.org/project/showfiles.php?group_id=154
>
>What would be the best and safest way to install it? A straight install with 
>rpm -ivh or recompiling from source? Or is there a version of it especially 
>for SL? Would appreciate your advice.
>
>No problem with WMP and Quicktime. These are taken care of by the Mplayer 
>plugin (both audio and video), though I am having some minor configuration 
>issues on that, which I am sure will be resolved soon.
>
>Thank you.
>
>Benjamin
>
>  
>