[mythtv-users] no audio on an fc6 myth 0.20 system

[Carlos Puchol]

hi guys,

it turns out that capitalization matters!!

	ALSA:default

works!

for the benefit of others, here is the way we found out.

xine could play the recorded files in /myth/recordings/*.mpg
just fine, with audio. however mplayer could not, initially. i.e.

 	mplayer file.mpg

did not produce audio. then i did

	mplayer -ao alsa file.mpg

and audio worked! ... then, doing this again:

 	mplayer file.mpg

audio worked ... no new messages in /var/log/messages or anything.
looking around, we found this by logging the frontend:

2006-11-04 23:30:58.118 Opening ALSA audio device 'Default'.
ALSA lib pcm.c:2143:(snd_pcm_open_noupdate) Unknown PCM Default
2006-11-04 23:30:58.120 AudioOutput Error: snd_pcm_open(Default): No such file or directory
2006-11-04 23:30:58.120 NVP: Disabling Audio, reason is: snd_pcm_open(Default): No such file or directory

changing "Default" to "default" in the frontend general setup for
audio device made it work.

it seems like there is some bit of state somewhere in the audio
subsystem. i'd need to know more about alsa to figure what this
namespace is all about (is it listed in /proc/ somewhere?)

we cannot get the mixer to work now, i.e. we cannot change the
volume in myth. we get this while logging the frontend now:

2006-11-04 23:56:48.040 Opening ALSA audio device 'default'.
ALSA lib control.c:910:(snd_ctl_open_noupdate) Invalid CTL mixer
2006-11-04 23:56:48.079 AudioOutput Warning: Mixer attach error -2: No such file or directory
                        Check Mixer Name in Setup: 'mixer'
2006-11-04 23:56:48.079 NVP: Enabling Audio

we have "ALSA:mixer", we have tried "default" and /dev/mixer also
but not "ALSA:Mixer" yet.

any ideas/pointers on that?

pointers on the general namespace for alsa devices, etc. would be
appreciated. i do notice some files in /dev/snd/* however,
they do not match "default" or "mixer" etc.

thanks!

-c

Carlos Puchol <cpg at users.sourceforge.net> wrote:
> in that menu, aside from /dev/dsp, it also offered something like
> this for the mixer:
> 
> 	ALSA:iec958:{ AES0 0x02}
> 
> note that i am not in front of the machine.
> 
> does capitalization/spacing matter?
> 
> i.e. is "ALSA: Default" different
> than "ALSA: default" and "ALSA:Default"?
> 
> what's this namespace in
> 
> 	ALSA:<X>
> 
> ??
> 
> i am not familiar to what can go in <X>.
> 
> one side note, which could potentially be related, is that
> in the soundcard recorgnition under FC6 there are two pcm
> devices, an analog and a digital for the nvidia chipset we have.
> the analog is selected by default, the other, when selected,
> does not render any audio. 
> 
> however, the more puzzling thing here is that all worked
> (somewhat briefly - for a few minutes)
> at my place _before_ we moved the machine to his place.
> 
> we're considering uninstalling the myth rpms, cleaning
> the database and starting over to see if the configuration works
> as the first time we did.
> 
> bian said:
> 
> > Also, remember that the HD-3000 does not embed the audio into the
> > MPEG stream like a PVR does. You have to handle it yourself.
> > I meant it does not encode mpeg if used for analog, obviously
> > if you;re using it for ATSC/QAM the audio is already there.
> 
> yes, atsc. we're picking up the channels off the air.
> we do know that the hdtv we have connected this to receives
> them well (i.e. audio works just fine).
> 
> we're trying to test the output off the card in isolation
> (no myth involvement) with dvb tools, such as what is
> suggested here:
> 
> http://pchdtv.com/forum/viewtopic.php?t=688&highlight=alsa+hd3000+audio
> 
> however, this is not working as smoothly as we would have
> thought. there is azap, czap, szap and tzap. they have
> slightly different formats for their channels.conf file
> (which is inconvenient and confusing). then there is the jargon,
> which we're catching up to...
> 
> thanks much for your suggestions!!
> 
> -c
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users