How do you inspect the contents of an exe? Is there a program to do that?
Admittedly, I still use it frequently when I am too lazy to convert my CD rips to FLAC.
(Another fellow FB2k user here.)
All other image formats get parsed to recreate either an identical or approximate bitmap as would have been encoded into the BMP file, but usually with more features or smaller size, or both.
All other audio formats get parsed to recreate either an identical or approximate audiowave as would have been encoded into the WAV file, but usually with more features or smaller size, or both.
[1]: https://en.wikipedia.org/wiki/Resource_Interchange_File_Form...
https://docs.microsoft.com/en-us/previous-versions/dd183376(...
Also now that many sources provide 24bit audio you need to check for that and resample to 16bit to be certain it'll work.