@marek-online Worked well with my Xubuntu 22,04 LTS here. I just created a backup of this original shitty ffmpeg and changed the second command to the corresponding folder in my computer:

sudo cp /snap/chromium-ffmpeg/34/chromium-ffmpeg-111306/chromium-ffmpeg/libffmpeg.so /usr/lib/x86_64-linux-gnu/opera-beta/libffmpeg.so

Thank you all for the tips!