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How to utilize Midi Beat Clock to sync lights

Posted: Wed Feb 22, 2023 2:48 am
by isoparmesan
I'm currently using QLC+ to program a fully automated light show for my band's live performance. The problem, is my current workflow is very tedious. In order to get chases or anything else to sync to the BPM of the section of the song, I map out each song section (verse, chorus, bridge, etc.) as a show, and set the BPM accordingly. I then assign each section a midi note, and have my sequencer send that note on beat 1 of that section.

I'm looking to switch from using the Show functionality, to triggering individual functions via faders that listen to midi CC which would come from a midi track in Logic Pro. This would be greatly simplified if there were some way to adjust my various chases (most of which are actually RGB Matrices) to adjust to the current bpm. The way I do this currently in the show manager is that any time I need a function to run at a different BPM, I duplicate it, and adjust the fade in/duration/fade out before adding it to the show. But if I were to continue doing this, I would end up with an exponentially growing mess of functions, tied to faders, tied to midi cc... you get the idea. at the very least I'd run out of Midi cc channels very quickly.

I've figured out that I can map the Midi Beat Clock channel (midi cc 531) to the Tap function of a speed dial widget in the virtual console, and then have that adjust the fade in/duration/fade out of whatever function I want. This only sort of works, since the tap function needs a few measures to "settle" on the tempo. So if the verse is 120 bpm, and the chorus is 125bpm, the first few measures end up registering as somewhere around 123BPM.

Is there some better way to detect the bpm and adjust my functions accordingly? Seems like this may be a feature planned for QLC 5, but I know that's not done yet.

Re: How to utilize Midi Beat Clock to sync lights

Posted: Wed Feb 22, 2023 9:21 am
by GGGss
Nice analyses of your problem - I hear ya.

QLC+ is not a timecode machine nor will it ever be IMHO. I stopped using the show part at all.
This brings us back to the essentials: being able to set the pace.
The catch-up of the beat by tapping is what is normal in the industry. If I have a 'running' drummer, I will quickly notice this and re-tap accordingly. For this, you need to be musically trained a bit...

Question here is now: how does your tempo come in? Does it seem to me with the use of a click track? So you already are quite synced. The difference in the tempo of the lights on stage won't be noticed between 120, 123 and 125 at last. And if you feel so: add some fade times (ex 160ms) and you'll love the new outcome. In the end there IS latency between stage and FOH...

I don't think there will be a direct setting possible of the BPM in v5. What if I want to have 123,2 bpm?

Re: How to utilize Midi Beat Clock to sync lights

Posted: Wed Feb 22, 2023 4:56 pm
by isoparmesan
Yeah, In my tests, the "catch up" that happens isn't super noticeable for a bunch of functions. I guess in situations where I really need things to be exactly on the beat, especially after a tempo change, I just need to have my console set up so I can control lights individually via Midi. then I can create those sequences in Logic, instead of as functions in QLC.

Beta 2 of QLC 5 does have a bpm counter at the top that is able to listen to midi clock, but I haven't quite figured out what it's tied to.

Re: How to utilize Midi Beat Clock to sync lights

Posted: Thu Feb 23, 2023 10:34 am
by GGGss
The BPM part of v5 is still under status 'partial' - So I wouldn't lay my eggs yet into the basket declaring 'because the is a midi sign on the BPM widget, there will be a possibility to use midi as an instrument to set a fixed BPM'.
Midi as tap source yes, a midi value for a BPM value no. Simply because midi is 7b whereas QLC+ internals are 8b / 16b. Midi has too less of a resolution to be precise.

Code: Select all

Say 60bpm to 400 = range of 340 -> 2,656 BPM per midi value.
120 BPM translates to 120/2.656 = 22,6 and because of 7bit
22 = 118,4 BPM (22 * 2.656 +60).
23 = 121BPM
24 = 123,7
25 = 126,4
Now I'm not sure about how the midi-clock works?

[edit] Very interesting article: https://support.redpandalab.com/support ... al%20tempo.
And even more interesting is how the jitter mechanism works (and how it mimics the beat tapping we perform as an LD).
Because MIDI timing clock sends 24 clock ticks per quarter note instead of 1 tap per quarter note, it enables tighter synchronization between equipment.
There you have it ;-)
[/edit]

Re: How to utilize Midi Beat Clock to sync lights

Posted: Wed Mar 01, 2023 1:14 am
by isoparmesan
Yeah, not banking on it at the moment. Just something that would be nice. As I'm moving more and more of my programming into logic, I'm realizing that I can just recreate the functions that I'd like to sync to beat in the piano roll there. Slightly more tedious than using the RGB Matrix, but it syncs perfectly.

Re: How to utilize Midi Beat Clock to sync lights

Posted: Wed Apr 12, 2023 7:51 pm
by mojo321
WOw, I just posted this same question... Geeesh, this is practically a deal breaker for QLC+ for me. It can receive MIDI triggers from Ableteon, but not use the MIDI clock to set the Chase tempo? Uhhhg.

Re: How to utilize Midi Beat Clock to sync lights

Posted: Wed Apr 12, 2023 11:21 pm
by prophy17
Pangolin laser company synchronized its laser soft Beyond and Quickshow with music by Laserbeat plugin of the Virtual DJ. And there are two ways for beat synchronization audio and light between Virtual DJ and QLC+ 4 version - os2l plugin and DmxArtnet plugin. They both are working good. And I don't understand - why there are so many fights))) in this theme.

Re: How to utilize Midi Beat Clock to sync lights

Posted: Thu Jun 08, 2023 1:17 pm
by mojo321
The thing is, I would like to set up one chase and use it on several different songs, each with different tempos. IT would seem a simple thing to connect the speed dial to match a tempo sent from midi. BUt It doesn't sound like that can happen. SOmebody mentioned loopback magic, and I have not explored it yet, so I am still hopeful.