Question about (tightness) incoming midi

[gentleclockdivider]

As you may know I'v been using the cirklon 2 to sequence vst''s in different hosts
Loomer architect and Reaper behave exceptionally well and have no problems processing dense midi input data and most important of at all , almost no jitter between notes , 32 , 64 th notes at 512 buffer size
Reason for this topic is perhaps you can give some insights in how you handled this , since one of my most beloved hosts 'Renoise' has problems when using the exact same buffer settings (512 samples ) all using assio 4 all driver .
Renoise needs a lot smaller buffer size (64 to 128 samples ) to accuratly process the incoming midi .
In all cases , the host are not sequencing anything
I am sorry to bother you with this , but perhaps you can give some info that I can then pass over to Taktik ( renoise dev )

[colin@loomer]

No problem: always happy to help where I can.

It sounds, from that description, that the MIDI message's sample offset is not being used. MIDI is a stream of events. As these events can occur at any time, they are tagged with an offset: the event's relative position in the buffer. Architect uses this sample offset to keep MIDI processing tight. (Caveat: eventually everything MIDI in Architect is squished to a PPQ of 960, which I think is accurate to about 8 samples at a tempo of 120 bpm.)

If this offset isn't used, another approach is just to treat each MIDI message as if it occured on the first sample of the buffer. For small buffer sizes, say 64 samples, this means that a MIDI message can at most be out by 63 samples. But as you have observed, once the buffer gets larger, so does the potential error.

[gentleclockdivider]

I've got another question
MIDI is serial , so in the hardware world , or daw -->hardware the packets are sended after one another , so there will always be a slight offest .
But what about the midi in daws triggering vst's ?
Multiple notes will always happen at the same time , does the midi uses the same protocol ( serial ) or not ?

[colin@loomer]

It's generally a different situation with DAWs, because they know ahead of time what notes are to be played at any position - they are on the piano roll, or in a MIDI file, etc - and so can ensure that all MIDI events for that sample are dispatched to the VST at once.