You could also put the file in a directory along with a unique file. The directory will have a unique hash (although the file will always have the same hash).
If you want every chunk of the file to have a different hash, you’ll need to either do what you’re doing there or, even better, just encrypt the file to each recipient.
Ive been reading about NFT music, where people are given the right to use their music without copyright infringement - I am assuming that they implement this 1 single file multiple hashes concept… but I am not entirely sure.
There’s no reason you’d need multiple hashes for what you’re doing. You could give out multiple NFTs, indicating that multiple parties have “licenses” to use the content. Of course, this won’t actually enforce anything but it will let people prove that they are licensed to “have” the content.
You’d only need a unique hash if you’re trying to sell unique “ownership” of the content (not license it to multiple parties). In that case, you’d have a unique hash by definition.
So if I were to create 100 licenses, I’d upload the song once, include the unique IPFS hash for that in the metadata, and in addition differentiate the 100 licenses in the NFT metadata e.g. an index between 0-100. So when someone purchases the license, they receive a metadata pointing to the same IPFS hash but different indices. Is that right?