Normal MIDI recording doesn't pick up already playing notes

[TubularCorpration]

Discussed in #1268

Summary of the issue:

-When recording a MIDI clip, any MIDI notes that were already playing when recording started aren't recorded.
-If such a note is released while recording, the note off isn't recorded
-Any additional notes that are played after recording starts are recorded correctly, regardless of any already-sustaining notes that don't get recorded

I've been able to consistently reproduce the issue in a fresh, empty project and it persists after restarting Reaper and after a full system reboot.

Reaper v7.24 and 7.25 and Playtime v2.16.10, under Windows 10 x64.

[helgoboss]

Ah, now I get it. You are playing the note not just before recording starts but even before the recording countdown starts, with quantized start timing. That's technically not a bug, but I guess it makes sense to add that, yes.

Here's an overview of what currently works and what not:

1. Holding a note before triggering a normal recording with immediate start timing: ✅ (synthesizes note-on)
2. Holding a note before triggering a normal recording with quantized start timing: 🚫 (to be added!)
3. Holding a note after triggering a normal quantized recording but before countdown reaches zero: ✅ (captures note-on)
4. Holding a note before starting to overdub: 🚫 (I guess that's not important?)

In order to implement 2, I would use the same technique as with "Immediate" start timing: I synthesize the note-on, not actually capture it. This means that I detect that there's a note-off without a corresponding note-on and then simply insert a note-on with a velocity that's similar to other notes that have been played during the recording (the actual velocity is unknown, since the note has not actually been captured).

[TubularCorpration]

What you describe as "synthesizing" the note is what I was also describing as the expected behavior, I just didn't do a very good job. It makes recording behave more consistently between MIDI and audio, which is more intuitive and personally I can't think of any scenarios where behaving thew ay it does now would be preferable.

Anyway, thanks for all the work you've been doing on it, it's already working very well and becoming a pretty indispensable tool for me even though I've never really gotten much from Ableton Live.