Epiphan Pearl Mini Live Video Production System - Manual (Page 248)

Pearl Mini User Guide Custom system variables for text overlays
Custom system variables for text overlays
You can create your own custom system variables using the HTTP API, which you can then use in text
overlays. This is useful to add custom overlay text that changes throughout the course of your live stream or
recorded program.
For example, using the HTTP API you can create a system variable for the current GPS co-ordinates, then use a
script to update the GPS co-ordinates in your custom variable as the physical location in your stream changes.
Here's an example custom variable called "gpsvar1" that has a value of "N103 68201 W765 29712". To insert
the "gpsvar1" variable into a text overlay, you'd simply type
%(gpsvar1) into the Text field.
System variable commands are issued at a frequency of 5 per second . You can include up to 6 variables in a
single set command. After issuing a set command, all channels using the specified variables are updated.
System variables are considered volatile and are deleted when the system reboots. See
Controlling Pearl Mini
using HTTP/HTTPS commands to learn more about global variable HTTP command syntax for custom layouts.
If you use a non-monospaced font, the size of the text overlay changes depending on the
characters in the content and the number of characters. To maintain a consistent size for the text
overlay in the layout area, use a monospaced font and make sure the number of characters
doesn't change.
For more informatoin about sizing and positioning elements in the custom layout editor area, see About the
custom layout editor .
Crop a video source
You can crop a video source to change the size and shape of your video as it appears on screen using the
custom layout editor. Cropping a source gives you a lot of advantages and can help to conserve the overall
amount of processing CPU usage for your Pearl Mini.
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