MIDI Duplicate Filter stop accepting notes after receiving two note offs (FIXED)

[cfillion]

I've been chasing around a seemingly random issue in my live setup where MIDI_DuplicateFilter would suddenly decide to stop accepting specific notes until it's manually reset.

Here's an easy way to trigger the symptoms:

1. Put the included MIDI_DuplicateFilter JSFX on a track with MIDI input
2. Press a note on the keyboard (don't release it)
3. Start transport -> REAPER sends a note off
4. Release the note previously held -> another note off is sent
5. Current: MIDI_DuplicateFilter won't accept that note anymore
   Expected: MIDI_DuplicateFilter ignores the second note off so further note on are accepted

Suggested fix:

Line 80, original:
tracker[note] -= 1;

Modified:
tracker[note] > 0 ? tracker[note] -= 1;

[X-Raym]

What is the purpose of the JSFX ?

[EvilDragon]

It filters duplicate notes?

[X-Raym]

@evildragon


What makes a note marked as duplicate ? What isbthe timing threshold for note of same pitch ? is it 0 ? or maybe duplicates notes is when two note on signal for same pitch are send one after the other ?

what become filtered none ?
do you use it ?
what can make duplicated note in a first place ?


Thx for your expertise :P

[cfillion]

It's a real-time equivalent to "automatically correct overlapping notes". It only lets trough the first note-on and the last corresponding note-off. It's very useful when routing multiple keyboards together. The bug described here happens when it receives more note-off than note-on events (the internal counter goes negative...).

[X-Raym]

@cfillion
Many thanks for your detailed explanation :P