[mythtv-users] audio issues (was: sounds when playing back recordings)

[Ray Olszewski]

At 08:41 PM 9/6/2003 -0400, John Goulah wrote:
>  Since nobody has a response for the post below, maybe someone can at least
>tell me what device is being used when watching pre-recorded shows and
>exactly what happens when a program is recording that would cause sound on
>pre-recorded programs to work all of a sudden.  Its as if it magically
>unlocks it and lets sound work.

John, this really is just repeating your original question in less direct 
form. If anyone had a good answer for you, based on the information you 
provided, you would have gotten it the first time around. Since you asked a 
second time, I'll take a shot at a not-so-good answer. Myabe it will be 
enough to help you.

The device used for playback is something you set up in mythfrontend, but 
it usually is /dev/dsp . This is often a symlink to /dev/dsp0, or maybe to 
/dev/audio/dsp0 (depends on the particularities of your Linux setup, not on 
Myth).  The actual device should be pointing to your sound card driver 
(alsa-something-or-other in your case), NOT the btaudio driver (from what 
you report below, this part seems fine).

As a general matter, I'd suggest checking your alsamixer settings and 
looking for something there that's causing the oddity you describe.

>  Also, does anyone know why btaudio appears to be correctly loaded but I 
> can't
>get sound from the line even when its muted and captured? Should I try a
>different alsa version?

As to btaudio itself, it is notoriously unreliable, in that many vidcap 
cards appear to support it but in fact do not. Search the list archives for 
many discussions of this problem with respect to specific cards; the HowTo 
may also discuss this problem by now. Since you don't seem to mention what 
vidcap cars you are using, I don't know if your problem with btaudio is 
this one or a misspecification of the audio device in Myth.


>Thanks!
>John
>
>
>On Saturday 06 September 2003 1:04 pm, John Goulah wrote:
> > For some reason I am not getting any sound when playing back a recorded
> > program UNLESS I set myth to record something while I want to watch
> > something I previously recorded. Other wise it doesn't work, but it works
> > everywhere else just fine (live tv, music, video).
> >
> > I had originally been using btaudio, but it doesn't seem to be working
> > correctly so I plugged the TV sound out to the mic input and am capturing
> > from that. (aplay /dev/dsp in xawtv with the mic captured and muted works
> > and thus live tv works fine in myth).
> >
> >
> > Btaudio seems to load ok (see dmesg below), but if I unhook the patch cable
> > I don't even get sound from live tv anymore.... Seemed to work before.
> > Maybe someone notices a problem here, but btaudio isn't the main problem
> > anyway.
> >
> > btaudio: driver version 0.7 loaded [digital+analog]
> > btaudio: Bt878 (rev 17) at 00:0b.1, irq: 10, latency: 32, mmio: 0xe6001000
> > btaudio: using card config "default"
> > btaudio: registered device dsp1 [digital]
> > btaudio: registered device dsp2 [analog]
> > btaudio: registered device mixer1
> >
> >
> >
> >  I'm really just wondering how I can get sound during playback of recorded
> > shows without having to record something in the background. I don't really
> > care about btaudio if I get this working. If anyone needs to see more
> > output let me know.