[mythtv-users] digital audio driving me crazy

[Phil Wild]

2009/11/9 Per Olausson <per.olauzzon at googlemail.com>:
> Hi. I am running Mythtv on ubuntu (mythubuntu) after getting rid of my
> previous setup based on gentoo (it was getting too demanding keeping up).
>
> On gentoo I used to (I believe) have digital audio all up and running fine,
> yet on this new setup I am scratching my head and becoming very frustrated.
>
> I have followed the wiki, other guides here and there and everywhere but not
> getting anywhere. I have 18 years experience on Unix/Linux so I know what I
> am doing. I think.
>
> Right. I cannot get digital audio playback working when watching something
> live on TV. Everything else appears to work.
>
> I get silence or cracks/squeaks. I have checked the board (DVB-C) and it is
> capable of AC3. Is there some kind of magic required to ensure that when
> recording or viewing something with AC3 the board is indeed getting the
> right sound out?
>
> I have played around with test.ac3 output and cannot get that to work
> neither. So I am assuming that something is wrong with my ALSA setup, but
> what I don't know. It is a nforce3 based board, I have an asoundrc file in
> my home directory etc.
>
> Does anyone have a minute/ideas or could point to a guide that certifiably
> works? It would be much appreciated.
>
> Regards,
>
> Per
I have the following also config file /etc/asound.conf

leave all mythtv settings as the defaults

phil at echo:~$ cat /etc/asound.conf
pcm.dmixer {
   type dmix
   ipc_key 1024
   ipc_key_add_uid false
   ipc_perm 0660
   slave {
      pcm "hw:0,3"
      rate 48000
      channels 2
      format S32_LE
      period_time 0
      period_size 1024
      buffer_time 0
      buffer_size 4096
   }
}

pcm.!default {
   type plug
   slave.pcm "dmixer"
}


Change the line that says pcm "hw:0,3" to match the output you are
using on your system (look at aplay -l and using card 0 device 3 on my
setup)

Cheers

Phil