Need Need help outputting Midi mpe SLIDE values to midi port

[danewhero]

Hello!


I'm trying to output MIDI MPE Slide values through a loopback MIDI port, but I'm having difficulties.

First, I'll say that I'm able to output every other MIDI value from Ableton that I could possibly dream of--MIDI CC messages, Program/Bank messages, Note On/Off, even MPE Pressure... But MPE Slide seems to have rules of its own.

Next, the specs of what I'm working with:

• Ableton Live 12.1.11

• Windows 11

• LoopMIDI v1.0.16

• Expressive Choir by Spitfire Audio, as my MPE MIDI instrument pack https://www.ableton.com/en/packs/expressive-choir/

I've enabled the Track values in Link, Tempo, & MIDI for my MIDI port (called 'LightTrigger', see above), but despite doing this, MPE Slide values simply refuse to be output through my MIDI port. MPE Pressure values are displayed just fine however, taking the format of:
[160, <MIDI note value>, <MPE Pressure value>].

By using the built-in MPE Control M4L Device, I figured out how to force MPE Slide to put out a MIDI message for its corresponding note by checking the box "Slide to Mod". But in all honesty, I don't understand what that checkbox means, or why I have to do it this way??
See below:



And, unfortunately, for my use case I need the MPE Slide value output to precisely match what's specified in Live. In a somewhat random manner, certain Slide values are off by +-1 (so even when the Slide Curve is a straight line from 0 to 127, certain values are still being skewed as if there's an unseen 'curve' that I'm not able to straighten.)

Lastly I'll say that the MIDI Monitor appears to be capturing the accurate values that I need, so I know all this is possible, somehow...

So does anybody know what I'm missing, or what I need to do to output MPE Slide MIDI values to my MIDI port reliably?

[pottering]

You select MPE in the 2nd drop-down menu in the "MIDI To" section of MIDI Tracks (WITHOUT instruments or audio FX).

So I think in your case you need an extra empty MIDI Track, with MIDI From set to that Expressive Choir track (probably Pre FX), then its MIDI To set to Lightrigger in the 1st drop-down box and MPE in the 2nd drop-down box.

EDIT: Oh, forgot the External Instrument device, you can use it instead of an extra track, its "MIDI To" works the same.

https://www.ableton.com/en/live-manual/ ... ngs-dialog

EDIT 2: "Slide to Mod" MPE Control is meant to be used with non-MPE instruments, it converts MPE Slide to the old non-MPE mod wheel.

[danewhero]

Hey pottering,

Thanks for your reply!!
Your suggestions didn't directly help me with the issue, but it prompted me to look deeper and I managed to figure it out.

Essentially:
Your suggestions and the MPE Control device were all doing what they were supposed to do in displaying the MPE Slide values... but, the reason why the values were sometimes off by +1 (never minus) was because when adjusting a MPE curve manually from within Live, the number might display "53" in an absolute manner. But in actuality, EVERY PIXEL COUNTS and even just 2-3 pixels higher could still show "53" but would actually be "53.87" or something. And all MIDI outputs will round this number up to 54 lol. So this is why my numbers were off.

I solved the problem by typing in the numbers specifically, so that they'd actually be absolute numbers.
You can do this by right-clicking the notes and selecting "Add Note" or "Edit Note" at the top of the options menu that pops up.

Thanks!

[Rivanni]

It's not the pixels, but rather the fact that the parameter internally uses decimals while only showing whole numbers in the interface. So small movements can change a value from 8.47 to 8.51, which rounds differently as you noticed.

You'll see this a lot in Live, unfortunately.