"How does one convert adpcm files into mp3/wav etc" . Foobar with Vgmstream plugin can play back almost all gamerips now, and can also convert to several formats (
https://www.foobar2000.org/components/view/foo_input_vgmstream ). Generally I recommend keeping the music in the original format. One last thing, Adpcm is a type of wav, so it is highly compressible unlike most other music formats. Store it as a rar to save space.