Re: [LAU] ALSA multi plugin woes, joining two cards

From: Len Ovens <len@email-addr-hidden>
Date: Sat Apr 20 2013 - 21:01:29 EEST

On Sat, April 20, 2013 10:06 am, Julien Claassen wrote:
> Hello everyone!
> I've still got problems joining my twosoundcards (Delta 1010LT and EMU
> 1212m). I've created the multi device for capture and playback, taken care
> of
> the bit width conversion and still it doesn't work. See the .asoundrc
> below.
> With Delta and EMU's analog I/O (device 0) JACK will start, but gives a
> lot
> of ALSA_PCM xruns. With the S/PDIF and/or ADAT/DSP part of the EMU card
> included JACK won't start or will shutdown immediately. Also
> ecasound/arecord
> won't work.
> Having tried the EMU S/PDIF on its own with arecord, I found, that it
> would
> only allow 8kHz samplerate, instead of the requested 48kHz. The EMU card
> is
> however setup to take the clocksource from the delta card, which works
> perfectly with 48kHz. OK, even it takes its clock from the outside (Lindy
> A/D
> converter).
> To test the S/PDIF in on the EMU I tried playing back something to the
> Delta's S/PDIF out, but only got silence.
> So it looks, like there is more than one problem. But I can't spot it.
> I've
> looked at the .asoundrc documentation again and the list of ALSA plugins.
> OK,
> there is the route plugin for creating interleaved audio, using the
> ttable,
> but for a start, I've read, that this will cause great latency. Anyway,
> I've
> built my JACK version myself and I don't see, why it shouldn't include
> complex

The first thing is that the problems with the 1212 should be looked at
separately. Also, there have been threads about pcm-multi on this list
before even with two "identical cards". Also, as far as I know, pcm-multi
and RT don't play well and even with a more relaxed kernel there are xruns
though they may not affect sound. Using alsa-in/out or zita-a2j and j2a
seem to have worked better in that case and may help in yours as well. Set
jack up as normal with the 1010 and add in the 1212 with alsa-in/out or
zita-a2j/j2a. (the zita package seems to use less CPU and is higher
quality... I am told, I haven't noticed one being bad) In this way it
should be easier to trouble shoot the 1212 problems because pcm-multi is
not involved and syncing is not involved either. So you should be able to
use the 1010 as a spdif input without interaction of the two kernel
drivers.

I'll think more... maybe look back in the LAU archives for other
pcm-multi/dual soundcard threads.

-- 
Len Ovens
www.OvenWerks.net
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Received on Sun Apr 21 00:15:01 2013

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