" you can use the smartphone to re-record a pre-recorded fake video."

I assume the intent is not to store solely a direct hash of the original video, but also the original file which can be fingerprinted, or the fingerprint itself that will be matched if a later duplicate is uploaded.

Fingerprint differing from hashing in that two non-identical, but similar files (e.g. an original video and deepfake) can have the same fingerprint, but differing checksums.