It seems that my android phone seems to perform better when sending midi out over usb midi (I would have expected the opposite).
First I thought it was only external midi out, but I've been able to witness the same with virtual midi (in the box).
The testing setup I ended up with:
Basically 2 multisynths: midiout is sending notes to puredata, and midiin is receiving those midi-notes from puredata (which simply echo's back the notes).
Puredata is running on the same machine (so it's virtual midi).
Here you can see an audio-capture, which (in the top) shows midi-notes which made the roundtrip to/from puredata, and in the bottom exactly the same notes going immediately to a sunvox sampler.
It's not terribly bad, but it is enough to notice..again, interesting fact is that my moto g4 android phone has tighter miditiming compared to my beefy laptop.
What I tried to resolve the issue (but didn't help):
* installing lowlatency kernel (http://tedfelix.com/linux/linux-midi.html)
* ran this quick scan (which doesn't score too bad to explain the jitter): https://github.com/raboof/realtimeconfigquickscan
Ps. probably a bug in the realtimeconfigquickscan, but I am running a PREEMPT kernel:
Code: Select all
$ uname -a
Linux ls540 5.11.0-41-lowlatency #45-Ubuntu SMP PREEMPT Fri Nov 5 13:55:43 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Anyone experienced this? Ideas? Tips?
I have dualboot, so I should check whether windows has the same jitter.