[ecasound] ALSA hints for multitrack recording

From: Cassettes2CDs <cassettes2cds@email-addr-hidden>
Date: Sat Feb 19 2005 - 06:45:27 EET

Dear ecasounders,

OK, just one more, honest.

(Allow me to disclaim that this is -not- an ecasound
issue, but an ALSA issue, and that I can be said to be
"hijakking" the ecasound list just a tad.)

This is about doing multitrack recording with ALSA.
Back in the OSS days I'd just fire off multiple
ecasound processes, each recording from a different
/dev/dsp#, and that was it.

But in ALSA, I can only record from the first of an M
Audio Delta 1010LT's stereo pairs:

     ecasound -i alsahw,0,0 -o file.raw

and trying to access anything else

     ecasound -i alsawhw,0,1 -i file.raw
     ecasound -i alsawhw,0,2 -i file.raw
     ecasound -i alsawhw,0,3 -i file.raw

gets me the same error:

(eca-control) ERROR: Connecting chainsetup failed:
"Enabling chainsetup: AUDIOIO-ALSA: Unable to open
ALSA--device for capture; error: No such file or

Here's a CC of what I asked to the ALSA-user list:

I'm another idiot who can't configure his sound cards.
This is a computer running the brand new CCRMA/Fedora
3 distribution with ALSA, and a couple M-Audio Delta
1010LT sound cards, which each have four stereo pairs
of input.
(Back when this old brick ran Fedora 7.2 and the
commercial OSS sound driver, everything worked A-OK.)
I need to be recording from each of those eight stereo
pairs (four per card) at the same time, into eight
separate stereo RAW files. Back in the OSS days, I
used ecasound for this, with eight separate processes
running at the same time.
My deal is that I can record from the first pair
(FWIW, it's -not- the everything-mixed-together pair
that comes from the hardware mixer):
      ecasound -i alsahw,0,0 -o file.raw
but trying to access the second, third, or fourth
      ecasound -i alsahw,0,1 -o file.raw
      ecasound -i alsahw,0,2 -o file.raw
      ecasound -i alsahw,0,3 -o file.raw
don't work.
So. Maybe a look at /proc/asound/cards and
/proc/asound/devices might be useful:
[craig@email-addr-hidden proc]$ cd /proc/asound
[craig@email-addr-hidden asound]$ cat cards
0 [M1010LT ]: ICE1712 - M Audio Delta 1010LT
                     M Audio Delta 1010LT at 0x8000,
irq 18
1 [M1010LT_1 ]: ICE1712 - M Audio Delta 1010LT
                     M Audio Delta 1010LT at 0x9000,
irq 19
[craig@email-addr-hidden asound]$ cat devices
  8: [0- 0]: raw midi
 16: [0- 0]: digital audio playback
 24: [0- 0]: digital audio capture
  0: [0- 0]: ctl
 33: : timer
 40: [1- 0]: raw midi
 48: [1- 0]: digital audio playback
 56: [1- 0]: digital audio capture
 32: [1- 0]: ctl
(BTW, what do those numbers mean?)
So anyway, folks, I KNOW that this is something dumb
and simple, but not dumb and simple enough for me to
figure out. I suspect that .asoundrc and/or
etc/modprobe.conf are involved.
I would feel much better if I can make this go without
having to "go through" any plugins or extra layers of
software, as I'm super-paranoid about minimizing the
load on the processor. Plus, I don't want to go
through any inadvertent/accidental amplifications or
rate-conversions between the card and the ecasound
Well. Cheers everyone, and thanks very much for your

--Craig Meyer
  Customer Service

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Received on Sat Feb 19 08:15:08 2005

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