[LAU] Combining two stereo devices on one card into one four-channel device (M-Audio FastTrack Pro)

David Balch david at balch.co.uk
Mon Jul 19 11:46:39 UTC 2010


> From: Patrick Shirkey<pshirkey at boosthardware.com>

> Feel free to ask more questions on this list

Thanks!


> Well to start with you can create a device with a specific name and then
> see if it is found by jackd:
>
> jackd -d alsa -dhw:mycard
>
> pcm.mycard{
>
>      type hw
>      card 1
>      device 0
> }
>
> ctl.mycard{
>      type hw
>      card 1
> }

Great, thanks.

Created a new .asoundrc with just that in [0], did `alsa-utils
restart`, and got this:

----8<----
$ pasuspender -- jackd -d alsa -dhw:mycard
jackd 0.118.0
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben
Hohn and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details


Memory locking is unlimited - this is dangerous. You should probably
alter the line:
     @audio   -  memlock    unlimited
in your /etc/limits.conf to read:
     @audio   -  memlock    3043752
no message buffer overruns
JACK compiled with System V SHM support.
loading driver ..
SSE2 detected
creating alsa driver ...
hw:mycard|hw:mycard|1024|2|48000|0|0|nomon|swmeter|-|32bit
control open "hw:mycard" (No such device)
ALSA lib pcm_hw.c:1401:(_snd_pcm_hw_open) Invalid value for card
ALSA lib pcm_hw.c:1401:(_snd_pcm_hw_open) Invalid value for card
ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to
capture-only mode
cannot load driver module alsa

----8<----

...which looks like a definitive not picking it up.

I'll file a bug in Launchpad, and see if that gets anywhere.

[0] To be accurate I changed it to card 0, as I'm on a different
Ubuntu machine. I'll test my main one later, at home.

Cheers,
Dave

-- 
http://www.witchesband.com/


More information about the Linux-audio-user mailing list