[mythtv-users] 0.24 upgrade, audio buffer underruns

[Jean-Yves Avenard]

Hi

On 24 January 2012 08:48, James Orr <james.orr7 at gmail.com> wrote:
>
> After the upgrade and experiencing this problem I did do a scan audio device
> and that option disappeared.  The comments for iec958 say ...
>
> SiS SI7012, SiS SI7012
> IEC958 (S/PDIF) Digital Audio Output
> Device supports up to 5.1 (digital output, AC3, DTS, multi-channels LPCM)
>
> This was the only item that mentioned S/PDIF, so it's the one I chose.
>  Should I pick something else?

If you are connected via digital coax or optical, then yes, this is
the device to use.

That it reports multi-channels LPCM indicates a bug in ALSA, myth goes
by what ALSA allows: and multi-channels LPCM should never be there
with iec958 device


> /proc/asound/card0/pcm0p/sub0/prealloc is set to 128
> prealloc_max is also 128

ok.. that's good
> StereoPCM resulted in no sound at all, but I seem to have it working now.
>
> I changed my device to ALSA:default:CARD=SI7012 and everything seems to be
> working now.  I guess I did pick the wrong one.  Thrown off by it not
> mentioning S/PDIF I guess.

You should be using ALSA:iec958 ; with StereoPCM checked to prevent
the issue of ALSA reporting incorrectly 6 channels PCM.

With ALSA:default, it's likely you will not get digital audio working properly.

I'd be interested in reading the logs when you select the iec958 one,
with stereoPCM checked.