De-/Encoder by onepiecefreak at 6:12 PM EDT on August 14, 2018
Hey there, I didn't test files from RE5, but I found FWSE files on some games by capcom on Android, that also didn't use standard encodings like OGG. And as Simon pointed out (as much as I dislike him), it's IMA ADPCM with a shifted index_table, that's the hack he mentioned.
Here's a link to a de-/encoder that at least can de-/encode this IMA ADPCM variation. If it doesn't work for the ones in RE5, open up an issue with some sample files and I will look into it. https://github.com/onepiecefreak3/SEWConverter
@onepiecefreak, Hey. Yeah, your tool does not support RE5.FWSE Some guys sent you some samples on github, so you can take a look. Thanks for your help!