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Processing Libraries
6

processing JAVA does not know capture or videoEvent

but you can
after install processing 3.5.3
install a video library via contribution manager
PDE / Tools / Add Tool /
Libraries / Video /

Video 1.0.1 The Processing Foundation  GStreamer-based video library for Processing.

after that might need restart processing IDE
find:
PDE / File / Examples / Libraries / Video / Movies / Frame /

using

import processing.video.*;

a example what play a existing video file and show next frame on [->]

if that is not what you want, please try again to describe what you want to do.
but above you say:

while in the first post you say

for that ignore all the video things and just use

and start from example:
PDE / File / Examples / Topics / File IO / SaveFrames

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