import stereo sound from blue socket

[jo...@wexfordpress.com]

The blue socket on e.g. a sound card or motherboard is alleged to be
line input.
I can set up a stereo device to send sound to this socket.

How do I coax Slack 14 to input this sound? Later on I can use some
ripper program to build up a file for burning a cdrom. But how does
Slackware recognize that I have an audio file to send and store?

John Culleton

[Henrik Carlqvist]

On Sat, 18 May 2013 12:53:45 -0700, jo...@wexfordpress.com wrote:
> The blue socket on e.g. a sound card or motherboard is alleged to be
> line input.
> I can set up a stereo device to send sound to this socket.
>
> How do I coax Slack 14 to input this sound?

man arecord

...might be a good place to start.

> Later on I can use some ripper program to build up a file for burning
> a cdrom.

Usually the term "ripping" is used the other way, when you get sound from
a audio CD to a file to your computer.

> But how does Slackware recognize that I have an audio file to send and
> store?

Does arecord answer your question on how to create a file from your
soundcard? Or do you need to know how to create a CD-DA-disc from your
audio files?

regards Henrik
--
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[Joe Rosevear]

It can be a little troubling. When it all works well you just set the
capture level by twiddling alsamixer. The display in alsamixer varies
from one sound card to another. I think it is safe to say that you
press F4 to see the capture choices, then find the control for line,
and press space bar to turn on capture for line. You'll see "capture"
in red when it is on. Use the up arrow to turn up the capture level.
Press M to toggle Mute on and off. MM means mute.

You'll need a cable to plug into the line-in connector on your
computer. A male-male, stero, miniature phono cable will do the job
nicely.

I record with rec (e.g., "rec test.wav") and use cntrl+c when done to
terminate the recording. I play back with play (e.g., "play
test.wav").

You'll want to pay attention to sound levels to get a good recording.
rec shows the levels while recording. ! means a "pegged meter" or
level too high, so adjust level with alsamixer to avoid this. The
normalize command is useful to give the recording a standardized level
after you have finished recording. E.g., "normalize test.wav".

Things get a little harder if you have more than one sound card.
Sometimes a sound card is hidden in a device such as a webcam.
Alsamixer's F6 allows you to choose which sound card you twiddle. The
choice of which sound card is used by rec and play is done with "export
AUDIODEV=hw:<n>" where <n> is the sound card number. E.g., choose
sound card 2 with "export AUDIODEV=hw:2".

This should get you started. Let me know how it goes.

-Joe
--
http://JosephRosevear.com
http://RosevearSoftware.com

[Joe Rosevear]

I was going to save the part about writing the CD until you asked. But
I have it handy now, so here it is.

1. Use rec as I described in my other post, but record to a file name
ending in ".cdr" and use a sample rate of 44100. Like this:

rec -r 44100 test.cdr

2. Burn it to CD with something like this:

cdrecord -v speed=16 dev=/dev/sr0 -audio test.cdr

Or specify multiple tracks:

cdrecord -v speed=16 dev=/dev/sr0 -audio test1.cdr test2.cdr test3.cdr

I think I got that right. If not, then let me know and I'll fix it.
Sometimes mistakes creep into my notes.