Hello,
On Wed, 6 Dec 2006, Stephen Cameron wrote:
Well, I sorted out the routing problems within my AW4416,
so now I can record multiple tracks from the AW4416 to the
PC via ecasound and JACK, but, still having a bit of trouble.
that's good to here! Let's move on to the other issues:
ecasound -c -r -b:128 -a:1,2 -i jack -o drums.wav -a:3,4 -i jack -o guitar.wav
This will work, but some notes:
- you don't need to give "-r" (automatic if sufficient privileges) or
"-b:128" (learned from jackd)
- the routing is somewhat wrong, as chains 1-4 (defined with -a) are
by default all stereo, so you for instance end up routing audio from
"-i jack" (two channels) to two stereo chains (2x2 channels) which
are again mixed back to "drums.wav" (again two channel)
What you probably wanted is (mono track for drums and guitar)
sh> ecasound -c -f:32,1,44100 -a:drums -i jack -o drums.wav -a:guitar -i jack -o guitar.wav
More info about ecasound's JACK support and the routing logic can
be found at:
http://eca.cx/ecasound/Documentation/users_guide/html_uguide/users_guide.html#htoc50
http://eca.cx/ecasound/Documentation/examples.html
http://eca.cx/ecasound/Documentation/ecasound_manpage.html (search for JACK)
If you want to play with JACK and ecasound, try also ecasignalview:
ecasignalview jack_alsa null
ecasignalview jack null
ecasignalview jack_alsa foo.wav
ecasignalview -f:32,12,44100 jack_alsa jack_alsa
... and do use also other tools (like 'timemachine') to make sure the
problem is not in a bad installation/bug in ecasound.
This works, but it seems small sections of the audio are
being dropped here and there, so the result is that the
transferred data is mostly correct, but is kind of "jumpy"
as it skips these apparently dropped sections, which are
short, but definitely noticeable. I suppose it could be
some issue with my OS, scheduling, etc., or possibly
cable problems. That latter I can rule out by moving
my computer, and using different, shorter cables, I guess.
My first guess this is trouble with the JACK settings (too low latency
settings for your current system and how it is configured). I'd recommend
trying witCh slightly larger settings of jackd period size and retry
the tests. Simply connect your soundcard inputs back to its outputs with
qjackctl and verify that the audio is ok (make sure any analog loopbacks
are disabled -> you don't hear any audio from the outputs until you
connected them with qjackctl).
Some tips on how to debug/trace JACK performance can be found for
instance at:
- http://jackaudio.org/faq
- http://ccrma.stanford.edu/planetccrma/software/installtwosix.html#SECTION000201000000000000000
--
links, my public keys, etc at http://eca.cx/kv
