I would rather not do this project at all (or for now) for several reasons:
consumer UHD is in its infancy, and there’s a bunch of professional decoders, etc that aren’t available.
Also, I have conflicting information whether the 4K is upscale or not
http://realorfake4k.com/my-product/guardians-of-the-galaxy-vol-2/ < says yes
https://www.imdb.com/title/tt3896198/technical?ref_=tt_dt_spec < says no