[linux-audio-user] Recording from Line-In

Rocco linuxmedia4 at netscape.net
Sat Sep 6 22:58:00 EDT 2003

garyb at cotecorner.com wrote:
> I'm having problems recording from line in.
> Without knowing exactly what's going wrong, all I
> can say is that I can only playback "silence."
> As I'm recording, I can hear the audio being fed
> back through the external speakers. I can also use
> various mixers to mute/unmute and set the volume on
> the "Line" setting. So I'm pretty sure everything is
> hooked up right.

I'm not that savy, but I know that I had to play around (a lot) with the 
various setting in "alsamixer". It's command line, so type "alsamixer" 
in the shell.

I will tell you that (from what I understand) it lists things that 
probly don't even pertain to _your perticular card_. So that makes 
trying all the settings more confusing. Also, I have found that 
"unmuting" or toggling "capture" modes on certain settings can cause a 
high pitch sound. So I would suggest that you already prepare (in 
another shell) the command that will restore your original "state". My 
main "state" file is located at /etc/asound.state. So I will use that as 
the example. If you get in trouble, do...  "alsactl -f /etc/asound.state 
restore" (no quotes of course).

Here's the catch though (at least on my set up). I found that the 
"/etc/asound.state" file changes every time I change my alsamixer 
settings (even if I'm _not_ root). So I would suggest that You move the 
"asound.state" to a different location and do... "alsactl -f 
/NewLocation/asound.state restore" if You get into any trouble. Once I 
get the right settings, I save the file to a different location by doing 
(I hope the syntax is right) "alsactl -f /NewLocation/NewName.state 
store". With that quirk of it always writing over the original 
"asound.state", I have "/NewLocation/NewName.state" always handy. In 
fact, I have it load during bootup because the original 
/etc/asound.state is always different with every session. But you can do 
what you need to do.

In alsamixer, I toggle "mute/unmute" with the "m" key (if it's muted, 
you will see "MM" at the top of the slider)... toggle "capture" mode 
with the space bar (the "-----" above a slider indicates it has a 
"capture" mode, and the word "CAPTUR" above slider means it's 
activated)... increase volume sliders with the "up" and "down" keys... 
and move from slider control to slider control with "left" and "right" keys.

Good luck,

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