I am running ubuntu 8.04. I have a chaintech av-710 that I wish to output ac3/dts for movies. however, I cannot get it to work. In fact the only audio I get at all is from rhythmbox (with mp3s). No other program gives me sound, even in two channel pcm. I have googled the problem but no one else's solution works for me.

DId you enble IEC958 in the Volume COntrol Panel?

Did you enable AC3/DTS passthroug in either SMplayer or VLC?

I tried enabling ac3 on vlc...I did not try smplayer. I enabled IEC958, but it did not help.

Which mobo is it?

Is IEC958 unmuted in the Volume Control Panel?

when I try to access the volume control panel via the terminal, the audio device is the onboard sound. when I do the volume control from the os itself, chaintech does not have IEC958, if I remember correctly (currrently I am in vista, I will check on the iec958 later).

ok, I do not have iec958 under the playback tab, only under switches and options. It is checked in both those tabs.

wow, I finally got it to work. I updated my asound.conf to match one I found online, and EVERYTHING works now. The video stutters a little, but I am sure that can be fixed.

You should disable the onboard (motherboard?) audio chip in the BIOs, which may have made the av-710 (VIA Envy audio chip) work from the get go.