Transformer object- fix note problem

Question

Hi, my first post!
I'm using a transformer-object in the environment to transpose
some incoming midi-notes in real time.
This works so far, but somehow, all the notes that are played, 'hang'
for some reason, like no 'note-off' command is been given.
Also, when a note is triggered, a second note is triggered at release and
being displayed in the matrix-editor.
Is there anyone who can help me out?
I'm stuck!

Answer 1

How I'd probably tackle it is to filter out all the note offs from the input stream first, do my processing to modify/transform whatever notes etc I needed, and add back in the necessary noteoffs when I finally pass the converted notes to the instrument - this won't in general be a problem with drum voices because they largely ignore note-offs anyway, as drum voices don't generally respond to gate time.
That way I know I always have a matching note-off following a note, and it's easier than trying to process the note-offs separately to match your note on processing, and keep everything in sync.
To generate note offs for a note on event, pass your modified note-on only MIDI stream to a final transformer, and the use "copy matching events" in whichever order you need, leaving the note pitch to THRU, and setting the velocity to zero, so every incoming note will pass through the transformer, followed by it's associated transformed note off.
If you have problems setting this up, post back and I'll take a look...
Edit: Hmm, transformers won't let you fix a note velocity to zero, at least in LP8. That's annoying.
I know I've done stuff like this before - I need to wait until I've got some clear head time to look at this... I think I ended up converting notes into other data types before converting them back into notes, specifically to break Logic's attempt at handling notes atomically, but can't remember offhand...