I"m helping someone with a video for their tutorial channel for tiktok editing. The premise, Can you actually create decent slow motion from 30/60fps video if you forgot to use it in camera at the time. My role to source material, convert it normal playback speeds, for it to then be converted to slow motion with optical flow. The material should be current viral tiktoks.

The source video to contain material that will fail dramatically, fail a little/work a little, and work well. Trampoline girl is what I expect to fail due to severe perspective shift, gymnastic guy I expect to work (I haven't tested these examples yet)

The problem I am having is trying to revert the slow motion to normal, because I can't see the speed curve, I am zoomed up on timeline stepping frame by frame looking for something obvious, and then pick where I approximate the curve is and do a speed change. As you can see both examples do not look natural at normal speed.

Is there a better way of seeing where the speed curve starts and ends in Vegas in pre-rendered video?

An assumption is made that slow motion video on tiktok is mostly recorded by iphone at 240fps, possibly 180fps, so I test this idea running the video at both speeds, to me Trampoline girl seems 240fps but ofcourse doesn't have to be, but if edited on a phone and not a pro editor it's unlikely to be higher than 240fps. Gymnastic guy I feel confident is 240fps slow motion.

I'll show you the examples plus an original file with many speed changes if anyone wants to try to revert slow motion to normal speed using a simple procedure.

This test file I've just noticed is 24fps, not the 30fps, but that's only a problem for optical flow, not reverting it to normal motion.