[LAU] midi triggering delay

[hollunder at gmx.at]

On Tue, 08 Sep 2009 14:48:27 +0100
andy baxter <andy at earthsong.free-online.co.uk> wrote:

> James Cameron wrote:
> > On Tue, Sep 08, 2009 at 10:14:24AM +0100, andy baxter wrote:
> >   
> >> - using a program which turns the computer keyboard into a virtual
> >> midi device. This makes the sound much more immediate. Having
> >> tried this, the contrast makes it obvious that there is still a
> >> problem with delays from the edirol keyboard.
> >>     
> > ...
> >
> > Watch /proc/interrupts while trying to play, and see what counters
> > increment in the matrix.  Here's a fun way ... run this in a
> > terminal window while playing keys on the MIDI keyboard ...
> >
> > 	watch -d --interval=0.1 cat /proc/interrupts
> >
> > What is the kernel version?  You mentioned Debian Testing and Ubuntu
> > Jaunty.
> >   
> I'm using a hand compiled kernel under debian testing - 2.6.26.8 with 
> the rt16 patch. I also tried a 2.6.29 kernel with rt23, but this
> didn't work. (May have been my mistake but I ended up with a problem
> with repeating keys and also the jack daemon wouldn't start properly.)
> 
> Will try what you've suggested and let you know how it goes.
> 
> Many thanks for the time you've spent looking into this.
> 
> cheers,
> 
> andy

He, so I was not the only one who got the repeating key problems with
2.6.29-rt. I think I had other issues as well.
Now if only 2.6.31-rt was out already :)

I use a keyboard with midi over usb and the output is over a usb
interface, yet I haven't noticed any annoying delay. At the moment jack
is set to 16ms, which of course is more when you measure it, especially
with usb.
But besides saying that it should work I can't really help you :/

Regards,
Philipp