[mythtv-users] ALSA and SPDIF Out For nForce2 Motherboards

[KianTeck]

Michael T. Dean wrote:

> That's the problem.  The section that I just had you change was the 
> section that defined a device called "default" (not called 
> "dmix-digital").  In other words, the default device is the device 
> used when no device is specified (i.e. a program uses the ALSA API but 
> doesn't request a specific device) or when the "default" device is 
> requested (i.e. for Myth, "ALSA:default").
>
> I suppose I should have included a nice comment at the top of the 
> .asoundrc listing all the valid devices defined within.  Anyway, the 
> only devices you should ever use are:
>
> analog
> mixed-analog
> digital
> mixed-digital
> default
>
> Note that if you leave the entire definition of "pcm.!default" 
> commented, default will be identical to analog.  If you redefine 
> default by uncommenting the 4-line definition of "pcm.!default" 
> default will be identical to the device associated with the 
> uncommented slave definition (mixed-analog, digital, or mixed-digital 
> from top to bottom as shown in the .asoundrc I posted at 
> http://www.gossamer-threads.com/perl/mailarc/gforum.cgi?post=119212&t=search_engine#119212 
> ).
>
> All other names in the .asoundrc--including "dmix-digital" are for 
> internal use only--they are virtual devices created as aliases to 
> allow reuse within the file.
>
> So, try using "ALSA:digital" or "ALSA:mixed-digital" and see how it 
> works.  (Or you could use "ALSA:default"--if you leave your .asoundrc 
> as is (based on the change you just made), this will be the same as 
> using "ALSA:mixed-digital")
>
> Mike 


No joy again.  This is part of my .asoundrc as advised:
------------------ <snip>----------------------
pcm.!default {
  type plug
## Uncomment the following to use mixed analog by default
#  slave.pcm "dmix-analog"
## Uncomment the following to use unmixed digital by default
#  slave.pcm "digital-hw"
## Uncomment the following to use mixed digital by default
  slave.pcm "dmix-digital"
}
------------------ <snip>----------------------

I changed the "Audio Output device" in mythtv to "ALSA:mixed-digital" 
and tried to watch live TV again.  This is what the mythfrontend says:
------------------ <snip>----------------------
Opening ALSA audio device 'mixed-digital'.
Unable to set hw params for playback: Invalid argument
Error setting audio params: Invalid argument
------------------ <snip>----------------------

I get the same deal too, as above, if I change the "Audio output device" 
in mythtv to "ALSA:default".  Anyway, I do not get the "Device or 
Resource busy" message in both the above settings now.

Setting .asoundrc in mixed digital, while live TV is running, and 
issuing "aplay /usr/share/sounds/KDE_Startup.wav" (via ssh) run 
immediately without any queuing.

I also noticed TWO other settings in mythtv audio setting (Setup | 
General | Audio) "Mixer Device = /dev/mixer" and "Mixer Controls = 
PCM".  Do I  need to change any of one of these 2 values?

>
>
> BTW, that also means that there wasn't necessarily another program 
> using your audio device.  Therefore, you can try both "ALSA:digital" 
> and "ALSA:mixed-digital" and use whichever you prefer.  I recommend 
> testing by watching some TV and causing the computer to play other 
> noises (i.e. ssh to the computer and issue an aplay) to see how sound 
> behaves.  If using "digital," the sounds will "queue up" (most likely 
> causing the application waiting for sound--here aplay--to block), but 
> if using "mixed-digital," the sounds will play (so the applications 
> won't block).
>
> Also, when you finish watching TV with unmixed output, you'll hear all 
> the sounds that got queued up--on my system, they play back much 
> louder than my videos, so it's quite scary to stop a playing video.  
> Because of that (and because the other sounds usually mean something), 
> I'm using mixed output (analog in my case because I'm hooked directly 
> to the speakers).
> _______________________________________________

I believe setting to "ALSA:mixed-digital" in mythtv should be what I 
want just to avoid surprises/shock at the end of a video session. ;-)

KianTeck