[mythtv-users] Simultaneous AC3/DTS passthrough & stereo analog output

[Gary Dawes]

On 18/10/2007, Bob <spam at homeurl.co.uk> wrote:
>
> I'm using an Audigy2 in one PC and an SB Live value in another (both
> Debian etch) and I output to a 5.1 speaker system over S/PDIF coax and
> to my headphones (via the TV) over analogue stereo.
>
> I have AC3 passthrough working when I call mplayer with -afm hwac3, (I
> think DTS will work but can't find a test clip) and I can soft decode
> and downmix the AC3 audio with -afm liba52, so that's all great, except
> that with -afm liba52 rear left and right are mixed and I don't get
> anything out of the LFE track.
>
> What I can't do is both at once which would make life easer for SWMBO.
>
> My google search (below) has reviled I'm not alone in wanting this
> (including a number of threads here) but hints that it may not be
> possible, however, my search skills are week so I thought I'd ask.
> "ac3 passthrough" "analog (output | stereo | downmix)" (simultaneous |
> "both at" | "same time")
>
> Has anyone got any suggestions on how to get this working?
>
> I can install more than one sound card, so if it can be done but only on
> a second card I'm still interested in the solution
>
> Thanks for any help.
>
> PS: Though the PCs in question aren't MythTV frontends at the moment,
> that is their destiny and since this community seems to be one of the
> most knowledgeable with regard to linux sound issues I thought I'd ask
> here.
>
> PPS: I asked the same question on the debian-user list 10 days ago but
> with no luck so sorry to those who, like me, are subscribed to both.
> _______________________________________________



I'm in a similar boat. I'd like to have analogue to the TV, as now for run
of the mill programmes such as the Wifey's soaps etc, and be able to have
AC3 piped over digital to the receiver when I'm watching a video or DVD.

Like you bob, I have googled extensively. I have also followed the guides on
knoppmythwiki and the general myth wiki, which suggest that it is possible,
but the examples shown do not work for me. I have a gigabyte MB with a
nforce2 chipset.

If anybody has got this working, example configs so the various solutions
can be compared would be very useful.

thanks also

Gary
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