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[Discuss-gnuradio] Sound card configuration
From: |
John R. Ackermann N8UR |
Subject: |
[Discuss-gnuradio] Sound card configuration |
Date: |
Tue, 09 Nov 2004 08:15:21 -0500 |
User-agent: |
Mozilla Thunderbird 0.9 (Windows/20041103) |
Hi All --
This may be a little off-topic, but (a) sooner or later I *will* be
using GnuRadio with this configuration, and (b) I figure the folks here
are quite likely to have been through this exercise.
Anyway, I am trying to get my SDR/spectrum analysis system rebuilt on a
Linux 2.6.9 kernel and am trying to get the sound system configured. My
applications will be GnuRadio, the SDR-1000 software once that's
release, and of most immediate importance, the "baudline" spectrum
analyzer software (http://www.baudline.com).
I have two sound devices -- the motherboard's VIA8233, which I only
intend to use for the occasional song played through the speakers, and
an M-Audio Delta44 which is going to be the main workhorse.
I'm having a dickens of a time getting everything to work.
First I tried the commercial OSS system from 4Front. With that, the
VIA8233 played the test file at about 1/4 speed. The Delta44 card
passed all the tests with flying colors, but when trying to run baudline
I got strange errors about requested fragsize being ignored.
After messing around with OSS for a while, last night I built the kernel
with ALSA support and downloaded all the Debian ALSA tools, plus
building the envy24control program from the alsa-tools package at the
ALSA website.
Now both cards seem to be working properly at the physical interface
level, but (a) getting both cards working simultaneously is a problem,
and (b) I can't figure out how to separate the 4 mono inputs from the
Delta44 into either two stereo pairs or 4 separate channels.
When both cards are installed, it seems that both want to use
/dev/audio0, and the first card loaded wins. How do I get each card to
talk (and listen) through its own device?
Second, what sort of magic do I need to make the individual inputs and
outputs on the Delta44 accessible? And, how do I direct a device to use
them? Right now, for example, baudline will display the signal from
hardware input 1, but it doesn't offer me any choice of input other than
"digital 1" on its device selector. How do I tell it that there are
multiple channels out there? I suspect the answer is in the asound.conf
or .asoundrc files, but cutting-and-pasting the samples I found on the
web don't seem to accomplish anything.
Any help would be *greatly* appreciated.
Thanks,
John
- [Discuss-gnuradio] Sound card configuration,
John R. Ackermann N8UR <=