[linux-audio-user] 8ins/8outs (analog) plus MIDI Audio card ?

Florian Schmidt mista.tapas at gmx.net
Mon May 9 18:20:55 EDT 2005


On Mon, 09 May 2005 10:16:43 -0500
Jan Depner <eviltwin69 at cableone.net> wrote:

>     You're supposed to be able to connect the 1010s together.  There was
> a thread on the list a while back about doing that but I don't remember
> what the result was.

I was wondering for a while about this. While it is possible to
synchronize the sample clocks of these cards probably by either sp/dif
or by wordclock, i do not know if this synchronizes interrupts, though.
I don't even know if ALSA has a mechanism to start two devices at the
same time (or as close as possible).

I suppose that when opening and starting a "multi" pcm device, the two
devices are started closely in time. How close is an interesting
question. So it's probably a matter of luck, but once started ok, it
might work very well.

I would love to be proved wrong though :)

The other question is: How well does jack for example work with a multi
pcm device? Could the userspace nature of pcm plugins possibly interfere
with the low latency requirements? Does it "inherit" the SCHED_FIFO
scheduling of jackd (in case it was started with -R)? What about
mmap'ing and additional latencies?

Flo

-- 
Palimm Palimm!
http://affenbande.org/~tapas/



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