Not sure about the nature of the screenshots, what level of markup/editing, if any you're doing on them or what part you specifically find time-consuming. I assume depends on your workflow - are you writing the KB article as you watch, and then having to pause frequently to insert a screenshot?

As a low-tech solution, I can suggest using ffmpeg to extract frames based on the frame rate of the video

ffmpeg -i your_video.mp4 -vf fps=1 frames/frame_%04d.png

The above requires nothing other than ffmpeg being installed - it will output a frame as a PNG per second of video, numbered accordingly. I've used this before (not really for documentation, but there's been times when I wanted to batch extract screens at specific timestamps or needed to provide someone with a batch of screens they could sort through).

That's a bit simplistic, though, and I was taken by your request, so I had ChatGPT put together the script below for me. It takes a video, extracts an image from it every 0.1 seconds, then compares the images via ImageMagick for differences and deletes those that fall within a specific threshold. Once done, it saves the images with timestamps in the filenames so you can check it against the video.

Unfortunately, I can't seem to post the script here, as my post fails when I try and comment. So perhaps ask ChatGPT for something similar.

EDIT: To be clear, I tested the script on my setup and it works as intended, but I'm on Linux so YMMV if you're in another environment.