Carl0745 wrote:
.... what about smooth fast motion (speeding up parts of clips), would it be the same thing just opposite? (retiming and then OP).
there's very little need/makes no sense to apply Optical Flow to a sped-up sequence ... just retime to 150, 200, 600% and you're done. Sidenote: you can drag the end of the Retime Bar to adjust the length = speed automatically...
Carl0745 wrote:
...How do you get those cuts in sync, ...
Read again my advice about the 'Dancing Finger' (I was quoted with this phrase, should probably patent it ... LOL)
look, a project, my main clip in the storyline, waiting anxious for cut-aways ...
music track is applied, I hit Play/space bar, music plays, and I hit here&there, now&then M
this sets the blue dots onto my main clip.
you can compare to the waveform: mostly close to the beat, but not every beat, #4 is (intentionally) off-beat, #5 is just off (me no good piano player), #6 back again, looks like 5+6 mark some 'epicness', ta-DAHHH! ... kinda ... sort-of
sidenote: yes, you look hysterically funny, muttering the music and tapping stupendously with one finger one key on the keyboard… probably, you should exercise this procedure in absence of spouse, kids or other persons who should respect you the following years ...
The dots igives you orientation, where to edit. What to edit, jump-cuts, 2framers, 5framers, slowmo, speed-up, flip pic, color changes, ... - that is your artist's decision
no, there's no 'easy' way accomplishing what we see & hear in your example. As said before: no witchcraft, but excellence in execution.... That was no beginners project ...