The short version of my question is: is it possible somehow to replace an item in the project panel (not a clip on the timeline) with an AE comp? If yes, then how, and if no... then the next part of the question will be longer. I'll have to describe what I need to do and ask for alternative workflows.
No you cannot.
Open the feature Replace footage and see which formats are supported.
What's odd is that I already tried that... and when I choose "all supported files" the AE project icon is still in the window. But when I choose it and click Open, I get a dialog that says Premiere crashed and needs to close.
So here's what I'm trying to do:
I have two 4K clips of talking head on a green screen that are average 45 minutes long each. I keyed them in AE (using the Keylight triple effect combo) and then export them as Prores with Alpha to use in Premiere, but the file sizes were just so astronomical and the render time would have taken over 24 hours each. So Plan B... I decided to treat the original clips as "proxies", as in, use them to do the timeline editing: cutting/zooming/adding text, etc. Then, I was going to just "replace footage" with the AE comps right before exporting (dynamic link). I already did a ton of timeline chopping and then realized I don't know if replacing footage with AE comps is even possible!! HELLO I should have finished my coffee first.
I'm pouting because I don't understand why it can't be possible. I can import AE comps... I can replace a timeline clip with an AE comp... so why not replace footage in a bin with them? Whatever no one cares probably.
Bottom line... I need to figure out a way to get this done. I wish I would have nested the original clips, and then edited the nests together. But I didn't think of that. Is there a way to solve any of this retroactively, or do I have to start over?
Curious... since I've already done a ton of cutting, and I don't want to do it again... is there a way that I could use either EDL or XML files to help solve this? I'm only vaguely aware of them honestly.
I'm thinking... is it possible to somehow
1. Export one of those files that lists all the edits I've made to the original clips
2. And then create new nests with those (unedited) clips
3. And then somehow use those EDL/XML files to reproduce my edits onto the nests?
If this is possible somehow, then that means that when I'm ready to export the final video, I could open the nest up and replace it with the AE comp in the timeline. That would be awesome.
It's usually not a good idea to do After Effects work on source clips. This results in a lot of unused data, as you're only using a portion of the clip in the edit and working with such large files makes it nearly impossible.
However, you can import a Premiere Pro project into After Effects, so you can apply the desired effects to the edited clips: https://www.premiumbeat.com/blog/premiere-pro-to-after-effects/
Hope this helps.
Thank you! That does make sense. I can see the silliness of my original plan now... (process the source clips in AE, then edit those).