Does anyone know of a way to put metadata in an mpeg file? or if its even possible. mpeg official sites allude to the ability but I can't find any info on how to do this.

I've created an mp3 player which can also act as an interface to other media players (I currently have plugins written for xmms, mpd, rythm box, totem and mplayer). with minimal work i could extend functionality to include mpeg files but i can't find so much as a snippet of information on how to encode metadata in mpegs.

thanks.