https://repo.herecura.eu/herecura/x86_64/opera-beta-ffmpeg-codecs-97.0.4692.36-1-x86_64.pkg.tar.zst下载并解压把
里面/usr/lib/下的libffmpeg.so复制到/usr/lib/x86_64-linux-gnu/opera/下重启opera浏览器