[mythtv-users] ALSA experts: Please help me configure SPDIF

[Juergen Botz]

On Mon, 2007-06-18 at 14:21 -0700, JDP DATA wrote:
> I've been try to get SPDIF output on my frontend with no success.  Please
> any kind souls out there help me.

I'm far from being an ALSA expert, and I have a different sound
card, but...

> aplay -L
> front:CARD=ICH5,DEV=0
>     Intel ICH5, Intel ICH5
>     Front speakers
> surround40:CARD=ICH5,DEV=0
>     Intel ICH5, Intel ICH5
>     4.0 Surround output to Front and Rear speakers
> surround41:CARD=ICH5,DEV=0
>     Intel ICH5, Intel ICH5
>     4.1 Surround output to Front, Rear and Subwoofer speakers
> surround50:CARD=ICH5,DEV=0
>     Intel ICH5, Intel ICH5
>     5.0 Surround output to Front, Center and Rear speakers
> surround51:CARD=ICH5,DEV=0
>     Intel ICH5, Intel ICH5
>     5.1 Surround output to Front, Center, Rear and Subwoofer speakers
> null
>     Discard all samples (playback) or generate zero samples (capture)

When I do this it shows (in addition to the above):

iec958:CARD=V8237,DEV=0
    VIA 8237, VIA 8237
    IEC958 (S/PDIF) Digital Audio Output

> aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: ICH5 [Intel ICH5], device 0: Intel ICH [Intel ICH5]
>   Subdevices: 0/1
>   Subdevice #0: subdevice #0
> card 0: ICH5 [Intel ICH5], device 4: Intel ICH - IEC958 [Intel ICH5 -
> IEC958]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0

Well, that shows that you have iec958 on card 0 device 4,
but for some reason the alsa config doesn't make an alias
for it.

What did you put in your Myth setup for audio output and
passthrough devices?  You might try "ALSA:hw:0,4".

> asound.conf
> #Generated by system-config-soundcard, do not edit by hand
> #SWCONF
> #DEV 4
> defaults.pcm.card 0
> defaults.pcm.device 4
> defaults.ctl.card 0

With this aplay should send audio to the digital out by
default.  There are some surround test .wav files out on
the net (I don't have a URL handy), what happens when you
play one of those with aplay?

:j