Well I've made some great progress!
Amazing, you're single-handedly making this mod more realistic every day. Any chance of a detailed run down of the steps you've figured out so far (fixing up the .uasset and so on) or, if it's what you used to fix all the files, the updated version of NOTter?
Well it's actually not that difficult now I know how it works, might a bit difficult to explain all the steps in detail though, but basically all you really need to do is hex edit the .uasset of the sound you're replacing it with, and change the paths inside to match the path of the BGM you're replacing... well I wish it was that easy, but just a few bytes after the path is a hash the engine uses to ID the path, you also need to change that hash to the same hash that's inside the .uasset you're replacing.
I wasted literally hours because I didn't figure that out sooner >.>, without the updated hash the game won't be able to find the sound and you'll just get stuck with a black screen.
Maybe tomorrow I'll write a more detailed guide about it since I'm a little tired atm... but there might not actually be much point now, since I just figured out how the BGM is actually encoded too
It uses a codec called HCA, which is a Criware custom thing, completely different to the Ogg codec the other sounds use, that HCA is wrapped in a "SQEXSEAD" container, which gives all the info about the sample rate/channel count/etc.
Luckily for us there's a tool that can decode these into .wav: https://github.com/bnnm/vgmstream-build ... test-u.zip
To decode with that you need to extract it from the .uexp first, then run vgmstream like "test.exe -o output.wav input.sab", and you should get a .wav file with the BGM all decrypted
(attached a quick app which will extract the SQEXSEAD stuff from a .uexp, just drag+drop a non-Ogg .uexp into it)
There's a HCA encoder at https://github.com/OpenCGSS/DereTore/wiki/HCA-Encoder
too, which I'm hoping will work to put new sounds back in, since I think this HCA stuff is the only way to get looped music working... I'll have a play around with that tomorrow.
Also did make an update for Notter to detect NOT'd files too, but it's really really slow, took around 2 hours to go through an unpacked data.pak and fix everything :/
It did do a pretty decent job though, found ~17,000 NOT'd files and fixed them, there's probably some it missed though, but that doesn't really matter much since we don't have to run it unpacked now
I'll post that up tomorrow though since I still need to clean it up a little.