MacOS - Midi decoding problem with two notes received at exactly the same time [fixed]

[jschultz16]

Background: I'm a show choir dad who's designing a light show for his daughter's team. This is my first attempt at this. I'm playing a click and cue track for our band, and syncing the lights to the music and the choreography. The click, cues, and MIDI notes come out of Ableton Live 12 Light. Those are mapped to ShowXpress LIVE Tab flash buttons in ShowXpress that are set up for MIDI input on specific channels. I've got an Xpress 512s pushing the DMX out to the rig.

While this is my first time doing this, I'm a software engineer by profession so the programming aspect of this has mostly "made sense" to me throughout. I've done the entire show on my work PC. However the school is providing a Mac as the system that will run the show at competitions. Considering Macs are used for all the tutorials I've watched on YouTube, and the Imagine series which I purchased to teach myself, I thought switching over would be a slam dunk. It is not.

I have this running successfully on two different Windows PCs. One running Windows 10, another running 11. I use LoopMidi to handle the communication between Ableton and ShowXpress, and it has been flawless.

On the Mac side, it's a Macbook Air 2020 M1. I'm using the built in IAC driver there. And Ableton can talk to ShowXpress, but it's dropping half of the Notes that are sent. By dropping, I mean to say that I've watched the MIDI logs and Notes are missing all over the place. I've also watched my LIVE tab, and of course there are button pushes missing everywhere.

Full admission, I'm a PC guy, so maybe I lack some kind of institutional knowledge on the Mac side that just makes this work for everyone else but me? What's further perplexing is seeing examples on YouTube of folks pulling this off on Macs, and in some cases the videos were posted over 10 years ago. Which means their hardware is certainly worse than the hardware I have now from the school.

Here's the show run from my work PC so you can see it's actually functional.

https://www.youtube.com/playlist?list=P ... I5i7SctmXu

I hope I'm missing something painfully obvious here and that someone will have the magic answer for me. I am willing to install anything necessary to help troubleshoot this, and am also happy to provide screenshots and logs from both systems if it would help.

Thank you in advance for any assistance!

Jon Schultz

[support]

The "Midi log" window of our software shows all midi messages our software receives.
So for an unknown reason, the system does not send some messages to our software.

[Niffo]

It sounds like what was said on this thread (in french) https://forum.thelightingcontroller.com ... php?t=8216

[jschultz16]

It sounds like what was said on this thread (in french) https://forum.thelightingcontroller.com ... php?t=8216

Niffo thanks for dropping in and trying to help. I've translated that thread and looked through it, and unfortunately it is not the problem I am having. All of my MIDI commands are transmitting on Channel 1. And I only need data from 0-127. I believe the user in that thread wanted an additional 128 data on a second data channel.

[jschultz16]

The "Midi log" window of our software shows all midi messages our software receives.
So for an unknown reason, the system does not send some messages to our software.

I don't know if you have different people running your support account on this forum? This non-helpful response above, I've seen quite a bit of in other threads. And then in still others, the support account has been both extremely responsive and helpful. It's like flipping a coin on any given day as to whether the response from your support is going to be useful.

We've spent $2000 on Chauvet lights (purchased first by our choir director without any technical knowledge). It's been up to me to figure this out, and the initial light purchase is how we wound up in your ecosystem. On top of that, another $300 on your proprietary DMX controller just to be able to send commands from ShowXpress to our rig. We're $2,300 in right now, so my expectation going forward is that you try a little harder to help.

I installed a MIDI logger on the MAC. Sure enough Ableton is sending ALL of the notes I've programmed. ShowXpress is the issue here; it's not picking them up.

More specifically, if multiple notes are sent simultaneously (in the test I'm doing right now, I'm sending 3 notes), ShowXpress gets ONE of them. And the ONE it gets is whatever note is lowest. If I send 0, 1, 2, it only gets 0. If I send 1, 2, 3, it only gets 1. I've tried adding additional busses in the Mac IAC configuration. They all behave the same way. At this point it's not even random. I can repeat the problem every single time. And now I've tried with just TWO simultaneous notes, and still the same behavior. The lowest note is received, and nothing else. I'm going to follow this post up with screenshots to prove what I'm telling you, but for now I'm going to hit "submit" on this message.

[jschultz16]

My IAC Driver on the Mac. I literally configured nothing here, just gave it a name:



My MIDI preferences in ShowXpress. These mimic what I've configured on the Windows side.



My MIDI settings in Ableton Live. Again, this is a carbon copy of what I'm doing on the WIndows side.



Here are the MIDI notes that actually get played. They are C-2 (which is 0) and C#-2 (which is 1)



Here are the MIDI logs from ShowXpress on the left, and Snoize MIDI Monitor on the right. As you can see, ShowXpress is completely missing C#-2 (1). If you want to see what it's supposed to look like, check the next screenshot from ShowXpress in Windows.



And here's the ShowXPress MIDI monitor on a PC, again, capturing all the output.

[jschultz16]

Is there somewhere I can download older minor and patch versions of ShowXpress 9? Perhaps this got broken in a more recent build and I can find something that will actually work on the Mac in a prior version?

Also, digging around I found a thread about a problem with the M1, however that just links over to the standard download page now which has the most current version. The initial post is also over 4 years old and claims to be fixed now.

https://forum.thelightingcontroller.com ... php?t=6901

The only prior versions I've been able to find are earlier MAJOR versions (8, 7, and so on), which are here:

https://forum.thelightingcontroller.com ... =85&t=4553

[Niffo]

We need to be able to reproduce this problem (which has apparently never been reported before) to be able to understand it.
You say that when you send several midi notes simultaneously, they are received in ShowXpress under Windows, but only one is received under MacOS.
Thanks for the clear report, we will do some tests on our side.

[Niffo]

We found an issue in midi decoding under MacOS when two notes are received at exactly the same time.
This will be fixed in the next Fix File.

[jschultz16]

This is welcome news! Thank you so much for digging in on this!