This modified version of fs.mitm let you randomize redirections to loose files in LayeredFS (Atmosphere CFW, Nintendo Switch). I only made it because i wanted to be able to randomize musics (BFSTM files) played in Splatoon 2. For example, in the lobby, the same music is played every time.
Copy/Replace fs_mitm.kip from this repo to your /atmoshpere folder.
Create a new folder inside /atmosphere/titles/<title ID>/. For example :
/atmosphere/titles/0100F8F0000A2000/randomMusic
Copy all the *.bfstm files you want to randomly play inside that folder. Don't worry about file names.
Instead of a *.bfstm loose file you want to redirect, create a *.bfstm.redir file. For example :
/atmosphere/titles/0100F8F0000A2000/Sound/Resource/Stream/STRM_Matching_Versus.bfstm.redir
The *.redir file must contain the path to the folder to redirect to, in plain text. For example :
/randomMusic
Don't put any carriage return or line feed.
Repeat the operation for any file you want to redirect or folder you want to redirect to.
Launch Atmosphere & play.
This is WIP. I only tested it with splatoon 2 (and atmosphere 0.7.4) but it should work with other Nintendo franchises (MK8, BOTW, Arms, etc).
The module allocates enough memory in LayeredFS to play the biggest files. It should work for other formats but i never tested it.
USE WITH CAUTION