SoundKonverter

Il parait que ca marche

http://www.kde-apps.org/content/show.php?content=29024

"soundKonverter a frontend to various audio converters.

When all plugins are installed following backends can be used:
oggenc, oggdec, lame, gogo, faac, mppenc, mppdec, flac, mac, mplayer, ffmpeg, shorten, ofr, ofs, wavpack, wvunpack, lpac, speexenc, speexdec, ssrc, vorbisgain, mp3gain, replaygain, metaflac

And when all these backends are installed you can decode:
ogg, mp3, mp2, m4a, mp4, aac, mpc, mpp, mp+, flac, ape, wma, ac3, rm, ra, ram, shn, au, ofr, ofs, wv, la, pac, spx, wav
... and encode:
ogg, mp3, mp2, m4a, mpc, flac, ape, ac3, au, rm, shn, ofr, ofs, wv, la, pac, spx, wav"