hmm... This's a known ffmpeg's issue and I was pretty sure it was fixed in our latest build of mpv 0.28
Seems like it was fixed upstream so you can just get the latest "official" build there and it's working (replace mpv.exe in SVP 4/mpv64 folder).
(However that build misses some built-in encoders needed for SVPcode and SVPcast)
Hey! That did the trick! Thank you very much for your help.
At the moment I do not use or need SVPcode or SVPcast so it doesn't really affect me, so having a fully functional SVPtube2 is more than enough!
Thanks!