How to change the transition point between two clips? (I.e. how to perform a rolling edit) Imagine I have a single clip, [clipA]. I now want to transition from normal colors to black and white. So I split the clip, and I add the black and white filter to the second clip [clipA1][clipA2]. Imagine the transition point is at time 1:20. Everything is great, and I continue editing. The clip transitions gracefully at 1:20 from normal color to black and white. [clipA1 0:00-1:20][clipA2 1:20-2:00]

Now imagine I want to change when the two clips transition point so that instead of doing a smooth transition at 1:20, it does it at 1:30. Naively, I may attempt to drag the transition point:



Problem is it only edits one clip when you drag the transition point and so I now have [clipA1 0:00-1:20][clipA2 1:30-2:00]. So there's a very drastic jump in the video from 1:20 to 1:30.

I could attempt to manually tweak clipA1, but I was hoping there is a GUI way to do this, similar to how in Final Cut Pro, I can tweak the transition point in multi-cam clips:



Update: In Premiere, they call this the "rolling edit" tool. As you drag one clip to the increase it's duration, it'll decrease the other the exact same amount.
There doesn't seem to be an easy way to do this either in iMovie nor in Final Cut Pro (except for Multicam clips).

Even these two methods will sometimes fail when they should have succeeded because the two clips might have gotten so out of sync that iMovie no longer recognizes them as two versions of the same clip.

Method 1 - rejoin clips

One way you can do this is to:


Select both clips
Join the clips
Re-split them somewhere else
Re-apply all the filters you had


Notably, this seems to be the only way to do it in Final Cut Pro as the following method only seems to work in iMovie...



Method 2 - dragging clips

Another way to do this is to drag the clip as you did normally. Notice how there is now a "break" between the two clips:



Drag the other clip until this "break" disappears:



This functionality does not seem to be available in Final Cut Pro, so this appears to be one instance where iMovie actually helps you more than Final Cut Pro.