[mythtv] pcm audio control while recording

Kevin Bowen mythtv-dev@snowman.net
Mon Jan 6 18:49:42 EST 2003

>No, I didn't say I was having problems hearing audio at any time, the issue
>is being able to play mutltiple pcm streams while being able to mute one.
Perhaps I'm not understanding your problem.... if you're recording a show
(and not watching it as it records) you should not be hearing any audio, so
there should be nothing to mute. The control names I listed are for
alsamixer, though it sounds like you probably are still using OSS... that
shouldnt be a problem AFAIK, the control names I listed will just be
different, though it sounds like you probably have it set right. DO you hear
audio while recording (but not watching live) in myth? or am I
misunderstanding you?

If you just mean you want a way to mute myth while its playing back video
(either live or prerecorded) without muting PCM out so that you can hear
XMMS, then no, theres no way to do that in the mixer - someone would have to
implement a mute function in myth... though I really don't see the point -
why would you want video to be playing back, muted?

-----Original Message-----
From: mythtv-dev-admin@snowman.net
[mailto:mythtv-dev-admin@snowman.net]On Behalf Of Harondel J. Sibble
Sent: Sunday, January 05, 2003 4:24 PM
To: mythtv-dev@snowman.net
Subject: Re: [mythtv] pcm audio control while recording

On Sunday 05 January 2003 02:05 pm, you wrote:
> If you're hearing audio from tv while recording (but not playing back)
> then you must have AC97 unmuted, and I would be surprised if you weren't
> therefore getting a feedback loop when watching live TV. You want to
> have 'Aux' and 'Capture' set as capture sources, 'AC97 Capture' and
> 'Capture' unmuted set to middle-ish volume, 'Aux' and 'AC97'
> muted/turned to 0. (this is assuming ALSA of course)

No, I didn't say I was having problems hearing audio at any time, the issue
is being able to play mutltiple pcm streams while being able to mute one. So
myth could happily be recording my shows without me hearing the audio and I
could concurrently listen to my mp3's.

As Isaac pointed out, the SBLive can play multiple streams, just can't seem
to audbly mute one of the streams.

I assume you are referencing the aumix settings above? I normally use kmix,
it doesn't have the items you mentioned. I have the creative desktop theatre
5.1 sound system and how one uses the mixer is rather odd....

What I have are

volume - ostensibly the master volume but has no impact on the rear speakers
pcm - I use this for volume control in mythtv and xmms
speaker - don't use
line - this controls the volume for xawtv, for myth, I normally have
muted, and record selected
mic - obvious
cd - can't remember what's hooked up to this, don't think anything is
lgain - controls volume in myth, if turned up more than say 20%, it results
in distorted audio as controlled by the pcm slider
ogain - this controls the volume on my rear speakers for most stuff and
the rear speaker live audio when I am watching tv in myth. If I shut down
mythtv and mythfrontend and then play a cd, I still get tv tuner audio out
the rear speakers unless I remove and reload the bttv drivers. If I mute
this,  that goes away but then I don't hear my music from the rear speakers
line1 - can't remember what this does, but it's important at some times ;-)
digital1 - controls volume for cdrom (plugged into aux on sound card)
phonein - never used
phoneout - never used
video - never used

So.... no I don't have any feedback issues and never have.

mythtv-dev mailing list

More information about the mythtv-dev mailing list