[LAU] midi triggering delay

[hollunder at gmx.at]

On Thu, 17 Sep 2009 19:17:26 +0100
andy baxter <andy at earthsong.free-online.co.uk> wrote:

> Clemens Ladisch wrote:
> > andy baxter wrote:
> >   
> >> when I play notes on the keyboard into fluidsynth, the notes are
> >> slightly delayed. The delay is small (around 0.1s ?) but enough to
> >> be annoying.
> >>     
> >
> > Is the delay constant or random?
> >
> > If you monitor the keyboard's output with aseqdump at the same
> > time, do you see the same delay when the notes are printed?
> >
> >
> > Best regards,
> > Clemens
> >
> >   
> The delay is variable - sometimes the note will sound almost 
> immediately, but usually there is a slight delay.
> 
> I've tried with aseqdump, and as far as I can tell there is no delay
> - 'note on' seems to appear at the same moment that I press the key.
> 
> I've also tried using zynaddsubfx instead of qsynth / fluidsynth, and 
> the delay is still there.
> 
> Which seems odd - I would have expected that if aseqdump was not
> showing a delay then the problem must be with qsynth. Maybe there's
> some library or code snippet that zyn and qsynth both share?
> 
> I'm wondering if it would help to install the whole of ubuntu hardy
> on my new laptop and see if that cures the problem (that's what my
> old laptop is running, which works fine.)
> 
> andy

I don't remember whether you said if it's the same with a sequencer.
I just thought I could point you to a little app that shows midi jitter.
With that you could play some monotonous repetitive stuff from a
sequencer and see if there are huge delays or breakouts.
The test, originally to test the sequencers, is described here:
http://tapas.affenbande.org/wordpress/?page_id=56

The app midi_timer-1.tgz can be found on this page:
http://tapas.affenbande.org/wordpress/?page_id=40
the delta-thingy might be most useful.

Philipp