loopback in action!

loopback in action!

[Kai Vehmanen]

ALSA kicks ass! :) Seriously, I'm currently writing a ALSA plugin 
for Michael Krause's soundtracker. It's still in early beta (output
only, scopes aren't working, etc), but simple module playback works
nicely. Anyway, I decided to finally do some real testing with ALSA
pcm-loopback and it proved to work amazingly well...

First, configured sountracker to use ALSA card 0 and device 0. Then 
started playing some mod file and on to another console...:

 ecasound -i alsalb,0,0 -o alsa,1,0 -etr:40,0,60

A reverbed version of the module comes from my speakers! :) And...

 ecasound -i alsalb,0,0 -o alsa,1,0 -efl:2000 -kos:1,200,4000,0.2

A lowpass filtered version with a 0.2Hz sine oscillator controlling
the filter cutoff! Don't know how useful this is, but this sure put 
a big smile on my face. ;) 

Software versions used were ALSA 0.4.0, SoundTracker 0.3.1 (w/ patched 
ALSA support) and ecasound 1.5.6r5.

PS The biggest problem was that if I tried to capture output from 
   my AWE64G, the capturing program sometimes exited with a 
   "Interrupted system call" error...

-- 
Kai Vehmanen ----------------------------- CS, University of Turku, Finland
 : email                                 mailto:kaiv@wakkanet.fi
 : audio processing for linux            http://www.wakkanet.fi/ecasound/
 : my music (ambient-idm-rock-...mp3/ra) http://www.wakkanet.fi/sculpscape/

Re: loopback in action!

[Bill]

Kai Vehmanen wrote:
> 
> ALSA kicks ass! :) Seriously, I'm currently writing a ALSA plugin
> for Michael Krause's soundtracker. It's still in early beta (output
> only, scopes aren't working, etc), but simple module playback works
> nicely. Anyway, I decided to finally do some real testing with ALSA
> pcm-loopback and it proved to work amazingly well...

Kai,

	I recently had a customer who has a hearing disability and uses
voice emulation and we were in need of driver that would eliminate
the POP that he was experiencing during .wav, .au, and .voc files,
not .midi though.

	He has an on-board Crystal Sound chip set. I can't recall the exact
chip but it was mentioned on the ALSA page, in the howto's. We ended
up using OSS. Any input on this would be appreciated for you seem to
be doing some good work from what I read. Thanks.

-- 


                     " vivit post funera virtus "
                                 
                  Linuxcare, At the center of Linux.
                      http://www.linuxcare.com                    
                                                     
             Bill Schoolcraft    http://www.wiliweld.com