Re: [Jack-Devel] Considering JamRouter, a low-jitter MIDI bridge for all Jack versions

On 07/10/2017 10:31 PM, Ralf Mardorf wrote:
> To reduce MIDI jitter for apps such as .e.g Qtractor, jack2 provides
> the "-X alsarawmidi" option sine many years and in the meantime jack1
> got something similar, too.
Yes that driver is nice, IIRC basically same code as the old external 
a2jmidi.
I seem to recall also someone recently posted they had fixed hot-plugging
  for that driver in jack(2?). Nice.
> To reduce MIDI jitter, there are other issues to consider, too, the
> kernel, the timer and what kind/s of interface/s is/are used, let alone
> the mobo.
>
I think the project mentions some of that, specifying to use an rt kernel.
It sure helps ensure the tightest possible timing.

(Hm, I have not used an rt kernel in a very long time, and I didn't use one
  when writing and testing MusE's midi external clock sync input support.
I was getting a lot of frustrating clock jitter! It forced me to write heavy
  multi-stage filtering and all o' that stuff, with user-selectable 
heaviness.
I really must go back and test with rt kernel. Wonder how it'll fare.
Funny I'm actually working in this area now...)

Cheers.
Tim.

1499745450.20597_0.ltw:2,a <c1a86e62-af32-df24-aba6-1b4332fe1bff at rogers dot com>