@devtiagofranca said in FFMPEG installation instructions:

# Ubuntu/Debian or based
# Install package chromium-codecs-ffmpeg

sudo apt install -y chromium-codecs-ffmpeg

## Make a link
sudo ln -sf /snap/chromium-ffmpeg/current/chromium-ffmpeg-103551/chromium-ffmpeg/libffmpeg.so /usr/lib/x86_64-linux-gnu/opera/

!!Warning!!

I tried this and it broke my installation, so be careful if you try it. Initially, it just broke YouTube, which I was using for testing, but when I tried restarting the browser it would no longer launch. Foolishly, I didn't back up the original libffmpeg.so file in the opera folder, so I had to reinstall the whole package. Always take backups, folks!