[mythtv-users] Assistance with digital audio configuration requested

[Mike Perkins]

On 19/08/13 20:52, John Nissley wrote:
> On Fri, 2013-08-16 at 14:28 -0700, Karl Newman wrote:
>> On Fri, Aug 16, 2013 at 1:10 PM, Joseph Fry <joe at thefrys.com> wrote:
>>          On Fri, Aug 16, 2013 at 4:02 PM, John Nissley
>>          <jnissley at nissley.org> wrote:
>>          > I am running close to the latest trunk of mythtv and for the
>>          last few
>>          > months I have been having some interesting challenges with
>>          digital
>>          > audio.
>>          > I am running Fedora 18 and an intel CPU with intel graphics
>>          and sound
>>          > drivers.  A few months ago the digital sound stopped going
>>          out through
>>          > my spdif connector and started going through my DVI
>>          connector that is
>>          > connected with a DVI to HDMI connector to my TV.  My TV has
>>          a spdif out
>>          > but it only works for TV stations the TV tunes and not sound
>>          coming in
>>          > from an HDMI port.  I am trying to get the digital sound to
>>          go through
>>          > my SPDIF connection so I can get it to my tuner.
>>          > Can anyone point me in the direction to get this resolved?
>>          > Many thanks..
>>
>>
>>          If the sound is being carried VIA the graphics cable, then
>>          most likely
>>          you have two sound devices in your system.  One is probably a
>>          standard
>>          Intel or Realtek HDA hosting your spdif.  The other is likely
>>          associated with your video card.  In mythtv's playback menus,
>>          make
>>          sure that your explicitly telling it to use the standard sound
>>          card,
>>          not the video card.
>>
>> There was also a change to ALSA in kernel 3.8 which broke S/PDIF. It
>> was about device numbering or something. It was broken in favor of
>> fixing HDMI sound, but I think a newer version of alsa-lib can fix it,
>> but you'd need to re-scan in myth. It may not solve your problem, but
>> it might be something worth exploring.
>>
>>
>> Karl
>>
> Thanks for your response. I am on kernel version 3.10.7-100 fc18 and my
> alsa lib is alsa-lib-1.0.26-2.fc18.x86_64.  Do you have any idea if this
> is the offending lib version and if so what is the best way to replace
> it with a new one.  I have even tried installing a stand alone PCI sound
> card just to make sure it was not in internal motherboard issue and
> still no success.  I have basically tested with all available sound
> outputs that mythtv give me and found that only the HDMI and analog
> outputs work.
>
Despite the electrical match between DVI and HDMI, I don't believe that a DVI 
interface will carry sound. You have to be HDMI end to end for that to work.

-- 

Mike Perkins