Mailing List Archive

Audio problem with line-in
Hello,

I have a problem with MythTV 0.7 which keeps me from using it.
I'm using an Avermedia AverTV card (bt878 based, mono, no radio tuner) and
an SB PCI 128 (ens1370). The TV card has an external cable that connects
to the sound card's line-in to get the audio.

The problem is that if I set the line-in as recording source and then start
MythTV, then when I pause the TV, the sound continues playing (through the
line-in) and when I make it continue playing, then I can hear both the
"old" audio (from the paused tv, played by MythTV) and the current TV
audio (which is directly played from the line-in).

I've read that I should mute the line-in channel, but then, there's no
audio at all (using both alsa 0.9.0_cvs20020320 and oss 3.9.7f). Yes, I've
tried to change the input gain, but it seems I cannot set it for my sound
card (?).

I've also tried to use the btaudio module to get the audio without having
to use the sound card's line-in, but it seems it doesn't work with my tv
card (bt878 rev17). All I get when loading that kernel module is a new
mixer with 3 channels which seem to do exactly the same, no matter from
which one I record (they're exclusive, I can only set the record source
from one of them each time). So, when I use
sox -c 1 -w -r 32000 -t ossdsp /dev/dsp2 -t ossdsp /dev/dsp
all I get is "clicks" and "pops" static noise (from every of the three
channels without any difference).

Can someone tell me if this can be solved somehow? or is my soundcard
defective?

Thanks, and congratulations for the great app.

--
Antonio Larrosa Jimenez
KDE core developer - larrosa@kde.org
http://devel-home.kde.org/~larrosa/
Furious activity is no substitute for understanding.
RE: Audio problem with line-in [ In reply to ]
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> I've read that I should mute the line-in channel, but then,
> there's no
> audio at all (using both alsa 0.9.0_cvs20020320 and oss
> 3.9.7f). Yes, I've
> tried to change the input gain, but it seems I cannot set it
> for my sound
> card (?).

Are you running KDE? (Note that it even though it says Mandrake 9.0
it's not really Mandrake specific) Here's an excerpt from the
mythtv-HOWTO in CVS: (section 6)

Mandrake 9.0
Open Kmix by K->Multimedia->Sound->Kmix

Click on Settings->Configure Make sure that "Tick Marks" and "Show
labels" have "X"'s in them. This will make it easier to find the
correct audio source. Click OK.

On the mixer page, look for Line-In on your sound card. You should
see two LED's - a green one at the top, and a red one at the bottom.
The green one at the top is for muting; you want to make sure that
the green LED is a dark green, meaning that it's "off". You also want
to click on the red LED so that it turns bright red, indicating that
it's "ON"; this insures that the Line-in is used as the source. Click
OK, and make sure that you save the settings so that this is your
default.

Does this help?

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