[linux-audio-user] connecting soundcards using JACK

[Jeroen Wijnhout]

On Tuesday 09 November 2004 05:29, Nathan Callahan wrote:
> It's not possible to start jackd on more than one soundcard.  You can,
> however use ecasound's jack output to kind of simulate it.
>
> Start jackd on the AC97 card, then issue the command:
>
> ecasound -B:rtlowlatency -f:s16,2,44100 -z:nomultitrack -z:nointbuf
> -o:jack -i:alsa,<iMic ALSA device>
>
> This is based on a script that I had set up to do something similar.  I
> can't quite remember why all of those options are there, so they might
> not be necessary.
>
> This may be a little unstable, but it's much better than trying to keep
> the soundcards synced properly.  No guarantees, YMMV.

Thanks for the tip. It sounds promising, but I don't get it to work properly. 
I've started jackd with:
jackd -Rv -d alsa -d default -p 512 -n 3 -r 44100
Everything runs fine (no xruns).

Then I start ecasound as you mentioned, which after a 10 seconds or so says:
- [ Engine init - Driver start ] -------------------------------------------
(eca-engine) Using realtime-scheduling (SCHED_FIFO).
(audioio-alsa) warning! playback overrun - samples lost!  Break was at least 
6.66 ms long.
zombified - calling shutdown handler
- [ Controller/Batch processing finished ] ---------------------------------
- [ Engine exiting ] -------------------------------------------------------
(eca-controller) Disconnecting chainsetup:  "command-line-setup".
(audioio-jack-manager) Connection closed!
- [ Chainsetup disconnected ] ----------------------------------------------
(audioio-alsa) WARNING! While reading from ALSA-pcm device C0D0, there were 1 
overruns.

At the same time I the jackd responds with:
subgraph starting at ecasound timed out (subgraph_wait_fd=9, status = 0, state 
= Running)
at 618674458 client waiting on 9 took 12732 usecs, status = 1 sig = 618661179 
awa = 618661187 fin = 0 dur=0
client ecasound error: awake_at = 618661187 state = 2 timed_out = 2
client failure: client ecasound state = Running errors = 1
*&*&*&*&** senor ecasound - you are a ZOMBIE
++ jack_rechain_graph():
client alsa_pcm: internal client, execution_order=0.
-- jack_rechain_graph()


**** alsa_pcm: xrun of at least 1.152 msecs

load = 1.3967 max usecs: 39.000, spare = 11570.000
load = 0.8965 max usecs: 46.000, spare = 11563.000
load = 0.5774 max usecs: 30.000, spare = 11579.000
removing failed client ecasound state = Not triggered errors = 0
adios senor ecasound
++ jack_rechain_graph():
client alsa_pcm: internal client, execution_order=0.
-- jack_rechain_graph()

Maybe I have to fiddle around with the settings of jackd and ecasound, however 
I have no idea what to change to what.

best,
Jeroen
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