[Updated for QLab 4.1 13 Jul 17 ]
Sometimes, it might be handy just to drag a whole bunch of video files into a QLab workspace and have an instant slide show with crossfades. Or to drag in audio files and crossfade through them with each GO trigger, without the need to set fades. And if there was random access, so the cues could be selected in any order and still crossfade, then so much the better. If you are using QLab 4 the tools to do this are built into QLab. In QLab 3 it’s a bit more difficult.
QLab 4 Method:
Here is a demo of a bunch of jpegs being dragged into a QLab workspace and being randomly accessed and crossfaded. (It would work just as well with audio cues or movies):
How it works:
We have to hijack the space bar so instead of it triggering a general QLab go as normal it triggers our OSC cue at the top of the list. We clear the GO in settings/Key Map
and assign the spacebar to the OSC cue in the cue list. In the same tab, we can also set the cue to ‘fade and stop’ all other cues every time it is triggered, in the time we set.
Then we set the OSC message that will be sent every time the spacebar triggers this cue. In this case, a simple go, to GO the cue that is selected. This is set in the settings tab next to the trigger tab.
Finally, before dragging in the video cues we need to set them so each time a video cue is triggered it is on the bottom layer, so it will be revealed slowly as the other cues fade. In settings/cue, templates/video set the layer to bottom
You can download the QLab 4 workspace here
QLab 3 Method:
Here’s a screen recording of a workspace with video cues:
And the same with audio:
How It Works:
First of all, we need to intercept all the GO triggers. (The on-screen GO button can’t be intercepted)
Disable the space bar GO; settings/key map:
Clear any MIDI triggers for GO:
Set the following triggers for a group cue numbered GO:
Hotkey Trigger: SPACE
Midi Trigger: Note 60 velocity >0
In the ‘fire first child and go next cue’ group is a script cue and a number of utility OSC cues:
These collapse nicely, hiding the workings from careless fingers.
The crossfade time is set in the post-wait of the group cue. This is a handy place to store user entered times used by AppleScript, as long as no auto continue or auto follow is set.
The only script is this:
The script sets the custom message for the fade to:
Where the 10 is whatever time is set in the post-wait of the cue numbered GO.
It then fires the fire all group which contains the OSC messages:
sets the layer of the selected cue, (if it is a video cue), to bottom
Panics the workspace, so everything currently running fades in the time set.
loads the selected cue
which is the OSC to GO the workspace and play the selected cue.
NB: If crossfade is running then any GO trigger is ignored (not queued).
You can download an example workspace here. This workspace requires QLab 3.1.10
The example workspace does not contain any sound or video content.
Put your own video and audio cues below the line in the workspace
Chapter Author: Mic Pool
Music in Demo Videos: “Dead Drop”, “Ominous Intro”, “Sapphire Isle”, “Supernatural”, “Time Passes” by Kevin MacLeod (incompetech.com)
licensed under a Creative Commons Attribution 3.0 Unported License.