[mythtv-users] Not the usual problem with digital passthrough.

[Michael T. Dean]

On 02/29/2008 11:59 AM, Robert Jones wrote:
>> Your ALSA mixer settings are incorrect for your card.  You need to
> It actually looks like the problem was either insufficient
> experimentation or user error, depending on how generous you're
> feeling.
>
> Messing with the upmix types didn't do anything.  However, while I was
> experimenting, I entered ALSA:plug:iec958:{AES0 0x02} to see what
> happened, because I wasn't sure if I'd tried that combination, and
> *that* did work.

Hmmm.  So you're saying that specifying the AES0 value--a value which is 
controlled using the ALSA toggle switches--fixed the problem?  ;)

http://www.gossamer-threads.com/lists/mythtv/users/319575#319575

> I now get the nice digital decode light on my amp
> when playing a DVD.
>
> I'm not exactly sure *why* this version worked when none other did,
> but I'm happy that it does work.  I need to find out more about ALSA.
>   

Because you changed the ALSA toggle switches...  Speaking of someone who 
doesn't understand what they're doing.

(Though, in truth, few ALSA users do understand what they're doing when 
it comes to ALSA configuration because they shouldn't need to understand 
it as much as ALSA requires them to understand it.  Therefore, I don't 
mean this as a jab at you, but as a jab at the ALSA configuration 
process, which expects users to be sound card/sound format engineers.)

To see how it works, start up alsamixer (preferably in a wide terminal 
window through an SSH connection) and start playback of one of these 
streams.  You'll see one or more (depending on your specific sound card) 
of the toggle switches change.  When you stop playback, it should change 
back.  If you didn't see any change the first time, scroll to expose 
different controls in alsamixer, then retry.  Eventually you'll find the 
control(s) affected.

Mike