How do you create these masks for live filter photo apps like this one?: https://www.youtube.com/watch?v=dmRJk0ZJsZk
What image editing program would you need? What kind of format are these?
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Your question has more to do with video than photography.
Anyway, if you want to add face masks on an existing video, you just need a video application with tracking capabilities (e.g. After effects, Hitfilm express, DaVinci Resolve etc.)
If you want to do it real time on a video stream you need some kind of video processing library and face detection library (e.g. OpenCV)