[mythtv-users] Asus M3N78-VM SPDIF

[Allen Edwards]

On Wed, Mar 25, 2009 at 12:42 AM, Phil Wild <philwild at gmail.com> wrote:
>
> 2009/3/25 Allen Edwards <allen.p.edwards at gmail.com>:
> > On Tue, Mar 24, 2009 at 6:36 AM, Phil Wild <philwild at gmail.com> wrote:
> >>
> >> >
> >> > this is OT ... can you switch between HDMI-audio and S/PDIF (IEC958)
> >> > in alsamixer?
> >> >
> >>
> >> I have the Asus M3N78-EM which is very similar to the mobo mentioned
> >> above and have been able to switch between the two audio outputs using
> >> alsa by simply changing the entries in /etc/asound.conf.
> >>
> >> I needed to add the following entry at the end of the file
> >> /etc/modprobe.d/alsa-base
> >>
> >> options snd-hda-intel model=6stack-dig
> >>
> >> Without it, I could not get the port to light...
> >>
> >> my /etc/asound.conf is below and I can switch between audio ports by
> >> changing the entry "hw:0,1" to "hw:0,3"
> >>
> >> ---start file----
> >> pcm.dmixer {
> >>   type dmix
> >>   ipc_key 1024
> >>   ipc_key_add_uid false
> >>   ipc_perm 0660
> >>   slave {
> >>      pcm "hw:0,1"
> >>      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"
> >> }
> >> ---end file----
> >>
> >> Cheers
> >>
> >> Phil
> >> _
> >
> > Hi Phil,
> > I am trying to understand digital sound as much as I can and wonder if
> > I could ask you to try some things.  If I have already asked you
> > please forgive me as I deal with digital sound with so many people.
> > Can you try this asound.conf file?
> >
> >  pcm.!default {
> >     type plug
> >     slave {
> >        pcm "hw:0,3"
> >        format S32_LE
> >     }
> > }
> >
> > Another one I have been wanting someone to try is this:
> >
> >  pcm.!default {
> >     type plug
> >     slave.pcm "hdmi"
> >  }
> >
> > If the later one works, I would suggest using it.  Finally, where did
> > you get the asound.conf file you are using?
> >
> > I will update my wiki,
> > http://www.mythtv.org/wiki?title=AllensDigitalAudioHowto, with the
> > results of your efforts.  This wiki is being widely quoted lately and
> > has helped a lot of people.  It isn't perfect yet and I will shortly
> > update it with the information Doug just gave and want to thank him
> > for revisiting this post.
> >
> > Allen
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> >
>
> Hi Allen,
>
> I recently purchased an MSI 8400GS graphics card so am no longer using
> HDMI for sound (have not investigated jumpering from the SPDIF riser
> to the card). I am running audio through the SPDIF optical port. I'll
> see if I can look at this tonight, depending on when I can get the TV.
>
> I can not remember where I got the configuration from for asound.conf.
> I have a feeling I found it following through some instructions for
> setting up xbmc.
>
> I do have one issue with audio at the moment in that it is running
> about 100ms faster than the video with vdpau enabled. It has been
> suggested that the x2 interlacers cause this but I have not had the
> time to confirm it. I am compensation by setting an audio delay in my
> receiver.
>
> Phil


I have been having good luck with this asound.conf file for spdif.
You might try it as it is possible your conf file is introducing delay
by resampling the signal.


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


Allen