@sgaist Yep, I added a link to stack overflow. Concerning vlc I already looked at it but sadly there is some major drawbacks :

-the documentation is poor or inexistant.
-it does not allow fine tuning what you want at compile time as much as ffmpeg allows it (to reduce shared libs size).
-it is partially based on ffmpeg anyway and I try to reduce as much as possible the amont of dependencies (for future compatibility and maintaining on my free time).

Again thank you so much for the quick replies and the mailing list 🤩.