[PLUG] Sound card won't record

Carlos Konstanski ckonstan at lunarlogic.com
Tue Aug 16 16:54:16 UTC 2005


Just a shot in the dark here: Is it possible that some other app is
holding the /dev/audio device open?  I believe (though I'm no expert in
this field) that the sound card can be used by only one app at a time.
When you fiddled with the loudness, you must have used some app to do
so.  Is it still running?

Maybe set up fluxbox or GnuStep as a debugging environment, which
doesn't have all the panel applets and stuff, and will therefore be
less likely to interfere with everything you're trying to do.  Or use 
TWM.

Permissions on the /dev/audio device?  When I first switched from debian
to gentoo, I went through the whole song and dance.  In gentoo, you must
be a member of the audio group to use the sound devices.  I don't
suppose this is your problem, as you made no mention that you just
switched distros.  Still, who knows if some recent package upgrade made
a policy change like this on your machine.

Often, the "device" which your apps point to is actually just a symlink
to a real device.  /dev/audio could easily be a symlink to /dev/audio1,
for example. Is the symlink still present?

Sounds like you're using a fairly sophisticated app to test your sound
card.  Why not remove some variables from the equation by attempting to
record with a more straightforward app?  Use "wavrec" to record sound to
a raw wav file.  It may be called "rec" on some distros.  May need to
get a microphone.  If that works but MythTV doesn't, at least you know
it's not your hardware.

Carlos

On Tue, 16 Aug 2005, Vincent Yau wrote:

> Date: Tue, 16 Aug 2005 16:11:20 +0000
> From: Vincent Yau <v_yau3 at hotmail.com>
> Reply-To: "General Linux/UNIX discussion and help; civil and on-topic"
>     <plug at lists.pdxlinux.org>
> To: plug at lists.pdxlinux.org
> Subject: [PLUG] Sound card won't record
> 
>
> Hi:
>
> I have been using MythTV to record TV shows.  My capture
> card does not have sound input so I rely on my sound card to record sound.
> It has been working for several weeks.
>
> Yesterday, I tried to play with the sound quality (by adjusting just the 
> loudness).
> And then my sound card won't record.
> I used the gnome-panel which comes with a sound recorder and volume control.
> No matter what I pick/choose to check the "REC" option, no sound is
> recorded.  As testing, I am merely using that sound recorder
> to see if it works.  Nothing is captured by that sound recorder.
> I think my soundcard is working as I can hear my TV when I plug
> in the MIC-in or LINE-in feed from my TV.
>
> I believe my sound card is /dev/audio.
>
> Can someone suggest some tips on how I can debug why my sound
> card stops recording input?  I have also checked and nothing is on MUTE.
>
> thanks for any tips.
>
> --Vincent
>
> _________________________________________________________________
> On the road to retirement? Check out MSN Life Events for advice on how to get 
> there! http://lifeevents.msn.com/category.aspx?cid=Retirement
>
> _______________________________________________
> PLUG mailing list
> PLUG at lists.pdxlinux.org
> http://lists.pdxlinux.org/mailman/listinfo/plug
>
>



More information about the PLUG mailing list