Le Lundi, 28 Décembre 2009 22:06:47 +0100,
Guido Scholz <guido.scholz(a)bayernline.de> a écrit :
Am Mon, 28. Dec 2009 um 15:24:02 -0500 schrieb lanas:
Not really. And I forgot to mention jackmix
which looks like
another quick hack.
Hm, yes that sounds pretty persuading.
Well, one or both (jackmix, QARecord) are doing it. Now, I think it is
clear, without looking at the code, that there's more effort put in
Ardour than jackmix, not on the amount of features obviously, but on
making it well-behaved in the context of Linux audio/jack apps. I'm
not certain, but I think the author of jackd is also author of Ardour.
Do not quote me on that.
> This is because it was not much of an experiment
to start with but
> rather an observation derived from finding a way to record the song
> without so many xruns.
I am aware of that and chose this wording to encourage
you to discover
the real root cause. Currently we suffer from hypotheses (at least I
do).
If, when I start my little project, I face the same number of xruns,
then I'll take a look. if not, my purpose is not to debug jackmix
and/or QARecord. I simply made an orbservation.
As such, the
observation was quite clear: kernel real-time
capabilities, although they might play a role somewhere, had nothing
to do in producing xruns since switching applications resolved the
problem. From that observation then a question arose: there must
be a bad way and a good way of writing a Linux audio/jack
application: what is it ?
So did you get the answer?
Yes. See the first two replies in ths thread, by David and Dominic.
As I added, treating jack callbacks as bottom part ISRs could certainly
improve performance and who knows (not I so far, do you ?) avoid a good
deal of xruns ?
> For
mathematical reasons I would like to get your result from this
> alternative setup (also giving better access to a root cause):
>
> 3) noise -> jackmix -> Ardour -> wav-file
Indeed. That's the possibility I haven't
explored since I think the
result of the observation was to see that there's a bad and good
way of writing such applications.
I see, so you are more interested from a philosophical (or moral?)
point of view.
I always tend to approach projects with a high-level overview before
delving into the details. As such I get a first round on how to define
objects, data paths, responsibilities, etc... Of course these will get
refined when details come in. That's how I do it.
Now, that the
bad way lies with jackmix
and/or Qarecord is a second point that has more to do with technical
performance in the context of writing such an audio/jack
application. Which is not the case at the moment.
Hm sorry, I didn't get that.
In other words, this is not about debugging jackmix and/or QARecord.
are you the author of QARecord by any chance ?
> > Some other interesting information would be,
what program versions
> > (jackmix, QARecord) are you using?
> Hmmm.. I'd disagree with this insofar as
debugging these apps is
> certainly not the matter.
So yes well, but are you sure, you understood my
question?
Yes. Program versions do not matter in that observation.
Tschüß.