increase PortMidi's input poll freqency from 20ms "Coarse" timer into 1ms "Precise" timer.
as I mentioned in https://musescore.org/en/user/57401/blog/2016/08/07/gsoc-2016-week-11-a…, the current PortMidi polling timer is only 20ms "Coarse" timer (giving maximum resolution of 21ms for received midi messages). I think that decision was made long ago considering that MuseScore didn't have a "semi-realtime" note input mode, but I think needs to be upgraded into 1ms "Precise" timer, to help prevent quantization noise.
Comments
I think I tried a precise timer on my machine and it made no difference, so I kept it as a course timer. But if it does make a difference for you then feel free to change it. (I was using PortMidi on Linux, not Mac or Windows.)
it may not be terribly perceiptible, but I think it makes a big significant when playing near or on the beat at faster tempos and need to determine which beat it goes on.