I tried to do a little research on Helix Player, but the website
to be down right now. It would be nice if dropping in a plugin of some
type was all it took to add MP3 (and Real) support.
I tried dropping the mp3 plugin files from RealPlayer in the HelixPlayer
plugin dir, and voilá! mp3 playback enabled.
I don't think the mp3 component is non-distributable, only the
RealAudio/RealVideo ones. A HelixPlayer-mpeg package might be possible
to host at rpm.livna.org
, for mp3 and mpeg4 playback.