[LMMS-devel] Fwd: Massive XRUNS using LMMS with Jack

[Paul G. <dr...@gm...>]

Forwarding to mailing list.

Lars, in the future send mails to the mailing list instead of directly to me.

---------- Forwarded message ----------
From: Lars-Erik Helander <le...@gm...>
Date: Tue, Jul 21, 2009 at 4:39 PM
Subject: Re: [LMMS-devel] Massive XRUNS using LMMS with Jack
To: pg...@gm...


Hi Paul.

I have now tested using ALSA.
The fact is that the sound is crappy already from start in that case.
But it does sound crappy in the same way, but more like
that LMMS can not cope with the incoming midi stream so that midi
events are dropped. Using Jack that was not the case, the
sound got crappy due to drop outs in the audio stream.


Hope this helps.

/Lars

2009/7/21 Paul Giblock <dr...@gm...>
>
> Lars -
>
> Could you please try repeating your test (LMMS with the 4 tracks and
> using aplaymidi) but use ALSA instead? Is the problem still there?
>
> I'm not suggesting you switch. I just want to know if the problem is
> in LMMS's MIDI routines, or if it is actually in the JACK code.
>
> thanks,
> Paul
>
> On Tue, Jul 21, 2009 at 9:49 AM, Lars-Erik Helander<le...@gm...> wrote:
> > HI,
> >
> > I have found a repeatable scenario where LMMS enters a state where it create
> > massive xruns with Jack.
> >
> > My setup is as follows:
> >
> >    - A TinyCore Linux linux based system with a custom built kernel
> > 2.6.29.6-rt23.
> >    - LMMS 0.4.4
> >        - 3 midi tracks with the SF player (soundfont merlin_vienna.sf2)
> >        - 1 midi track with zynaddsubfx
> >    - Jack(2) version 1.9.3 (and also tested with 1.9.2)
> >    - aplaymidi feeding the LMMS midi inputs (same midi sequence sent to all
> > 4 tracks)
> >
> > When I start aplaymidi it all works fine for a couple of minutes. After
> > about 3 minutes xruns starts to show up and they are
> > increasing in frequency. After about 5 minutes from the start the xruns
> > comes every second (at least).
> >
> > I have tested various actions when LMMS has come into this mode of continous
> > xrun "creation".
> >    - stop/start aplaymidi : the problem remains
> >    - stop aplaymidi, reload the project, start aplaymidi: the problem
> > remains
> >    - exit the lmms application using the exit menu selection, start lmms
> > again: problem is gone but if I now start aplaymidi again
> >
> >                                      the same situation occurs after a few
> > minutes again
> >    - exit the lmms application by closing the main window: see previous line
> >    - kill the lmms application, start lmms again: the problem remains from
> > start
> >
> > My guess is that the lmms application runs out of some resource (either
> > provided by some file system or by the kernel) and when
> > the application terminates in a controlled way (not killed) the resource is
> > properly reclaimed. But what resource could it be in that
> > case?
> >
> > Do anyone have a guess on what the cause of this could be?
> >
> > Kind Regards
> >
> > Lars
> >
> >
> >
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