nostr:npub1gajvsj4vhehzjtpq9sax45j49qa623vtl6fu6djjrjzm05w48l8srt78dz What about this then? Someone made a context menu converter (for Windows) for FFMPG that can extract wav, aac, m4a, mp3 etc from MKV.

https://forum.cockos.com/showthread.php?p=2347240