What would best 4k transcode media for a 15 sec video?
MacBook Air (M1, 2020)
I have to say you are completely off the mark, here.
Creating proxies has nothing to do with upscaling.
It is meant to create smaller, easier files to edit inside FCP, not to export or convert anythings.
Once editing is done, one typically deletes these files, they are never used outside, and they are never bigger than the originals.
It seems to be that you are under the incorrect impression that 4K will be somehow "better". Most users on youtube will never see it. Youtube serves different versions depending on the device and network connection.
Even if you produce a marvelous 4K or 8K, no user on a phone or tablet will ever see them, and even those on a computer with a huge screen may or may not see them.
That aside, you could simply put the files in FCP in a 4K timeline, and export that. That would probably be good enough. Or you can spend money on software that tries to cleverly upscale, but that would be ill advised unless you really know what you are doing.
I can't see 4K bringing anything more to the table.
Be warned that Topaz etc. takes an eternity to render so is only really useful for short clips unless you don't mind prolonged waits.
Best Final Cut Pro Transcode Media
