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

[John Goulah]

On Saturday 06 September 2003 8:59 pm, Ray Olszewski wrote:
> 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.
>
>
> 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).


mine is pointing at /dev/dsp which is a symlink to /dev/dsp0 . But if 
pre-recorded shows use that device why does it work fine outputting all other 
sound (music, tv, video) and work when I am recording in the background. 
Seems like a developer would know what would be "unlocking" it (for lack of 
better terms). 

I do have a /dev/audio (but no /dev/audio/dsp*). Never had dsp device pointing 
at that before and it had worked. I'm not sure what this device is.


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

i have fiddled with it to no end and am getting odd results. For example it 
seems like if the patch cable is plugged into the mic input it works, but if 
I use the line input I can't hear anything. Also, I have had this configured 
correctly in the past so I know what the settings are supposed to look like.

>
> >  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.


I am using an ATI TV Wonder. Worked with btaudio in the past. I'm not sure if 
I misspecified the device in myth or not, but I have tested the capture card 
both on /dev/dsp and /dev/dsp1 which both work with a patch cable for live tv 
but not with btaudio right now. My general sound settings use /dev/dsp as 
output and /dev/mixer for the PCM.



If anyone has any other ideas of anything i could try please let me know


Thanks
John