@citizenjoe said:
Damn. I wonder how QLab does it?
QLab's cues (to the best of my knowledge) can't change the media target of a cue programmatically (and if it is possible, I'd wager it's much less common), so it's either not possible or very unlikely to run into the problem I described with QLab.
Consider the QLab file and the Isadora Scene in this screenshot (forgive me for whipping out QLab 4, I'm testing something in Isadora on Mojave and QLab 5 requires macOS 11.x Big Sur):
Both cycle through the same five pictures, but QLab has/requires a video cue for each of the five pictures. With Isadora you can combine the Get Media Count, Pulse Generator, Counter, Picture Player, and Projector actors to cycle through the same five pictures, but if you look at the file in a static state, only one picture is "in use" by the Picture Player actor at a time.
I use both QLab and Isadora and have programmed many simple and complex shows using both (sometimes utilizing both applications on the same show), so I'm not trying to praise one and bash the other here. Both have their strengths, weaknesses, benefits, and drawbacks. Example: Because of the way QLab requires a video cue for each of the five pictures, it knows that all five pictures are used in the project, whereas Isadora doesn't. However, if I wanted to add 600 more pictures to the loop, with QLab I'd need to either add 600 more video cues or change my approach and figure out a way to cycle through all the pictures with a script cue changing the target of a video cue every second (or something similar), whereas with Isadora, the patch in the screenshot would already work and cycle through all 606 pictures as soon as you imported the new pictures (because the Get Media Count actor would automatically up the 'maximum' on the Counter actor).
QLab is excellent to use for linear cueing simply because it already provides you with pre-built functionality and structure intended to make linear cueing easier (though it can handle programmatic control of cues and non-linear cueing using the play, stop, pause, load, reset, devamp, goto, target, arm, disarm, wait, and script cues). Isadora files start as a blank slate which, while it allows for lots of flexibility, means that you don't immediately start off with as much pre-built structure focused on linear cueing (though there is the default spacebar go trigger, you can drag media into the Scene Editor to create a Player actor already connected to a Projector actor, you can set scene fade times, etc.). Instead, Isadora's flexibility makes it possible to go in the direction of linear cueing if you want, but also easily allows for non-linear cueing (e.g. the Activate/Deactivate/Activate Scene Amount actors), programmatically-controlled cueing (e.g. using the Get Media Count actor), and live changes to cueing (e.g. with Control Panels and MIDI controllers). Neither software is better than the other in every case (in my opinion) though one can be a better idea to use than the other depending on the needs of a specific project. Overall I think it's extremely valuable to know how to use both.
