playing ac3 (Dloby Digital) sound with a G5

[Guest]

I've a G5.
Is it possible to listen to a dvd using the optic audio out?
I have a G5 connected to a 5.1 home theatre using optical out. It seems VLC can't handle ac3 dobly digital files.
I can play DVDs in dolby digital using apple dvd player.
I'd like to listen in dolby digital also divx files (the ones ac3 encoded, of course...)
VLC tells me "coreaudio: failed to set buffer size: [nope]" error.
Any idea on settings, maybe

Thanks

[The DJ]

You should search the forum before you ask questions.