Lots of ^^
All ff7 specific tools to extract textures, extract fmv from psx cd, unpack/repack lgp, edits some of the scripts (for 3d models)...
To do the upscaling it's mostly based on esrgan with specifics AI model and mix several results with gimp to get the best of each AI model + manual correction (mostly signs done by Aavock) and looooots of ingame test to hunt for texture bugs and do manual correction.
It's not an "oneclicktooltodoallthejob" it was a complex and (very) long work to get this v5 textures and the AIO pack as it is now