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.