MIDI triggering next scene only works once

[bugsduggan]

Hi folks. Long time lurker, first time poster etc.

I'm on Ubuntu 24.04
Qlc+ 4.12.7

I'm attempting to get Linux Show Player (LiSP v0.6.4) to output MIDI signals to trigger the next scene in my qlc cue list in the VC.

I have MIDI signal coming in to universe 2 (can see the joystick) and no profile loaded (I like to live on the wild side). My MIDI plugin is listening on channel 1 for control change signals.

In my VC, I have successfully auto detected the correct universe and input channel. Once I switch to operate mode and fire my MIDI cue from LiSP, qlc correctly steps to the next cue in the list. If I fire the same cue again, qlc ignores it. Switching back to the inpus/outputs tab, I can see the universe is still receiving MIDI data.

I've also tried sending MIDI signals using SendMIDI in place of LiSP (to prove it wasn't LiSP causing the issue) and that has the same behaviour: works once after a restart but only once.

If I save everything, close qlc and re-open it, firing the cue from LiSP will work again but only once. All subsequent MIDI signals are seemingly ignored.

I'm fully prepared to accept that this could be user error (I actually kinda hope it is at this point) but if this is a bug (especially one that might have already been squashed), I'd love to have some more context for what's going on (or even how I could fix it).

Thanks in advance

[edogawa]

You have to find a way to reset the control message, i.e. send a second message with value 0 right after the first one with value 127.

I've just tested with LiSP 0.6.4 and sending CC1 on channel 1 with value 127 does just what you describe.
After adding a second MIDI cue with the same controller and value 0, and combining this in a collection cue, it works as advertised.

I found out by looking at the MIDI output from a NanoKontrol2 button with Drumstick MIDI Monitor. The buttons send whatever CC, ch 1, value 127 at button press, and value 0 at release.

[MichelSliepenbeek]

... and no profile loaded (I like to live on the wild side).

If you are willing to use an Input Profile, you can also set the "Generate an extra Press/Release when toggled" option.

If you read the on-lne manual (https://docs.qlcplus.org/v4/input-outpu ... profiles ) and read the "Button Properties" section, you will find:

Generate an extra Press/Release when toggled: this is a quite specific option used for example when dealing with TouchOSC or the Behringer BCF2000.
QLC+ toggle events are triggered when a high+low sequence is received. This means that QLC+ expects a non zero value (typically 255) followed by a zero value to toggle, for example, a button.
Devices like BCF2000 or software like TouchOSC, instead, send just a non zero value when activating a button, and a zero value when deactivating it.
When checking this option, QLC+ will generate the "missing" events to standardize the way some controller work. So, for example, the BCF2000 will look like sending 255+0 when pressing a button, and another 255+0 when pressing it again.

[bugsduggan]

Thank you both so much for your help. The problem seems so obvious now that you've explained it.