Name: Opera (ffmpeg!)
Homepage: opera.com
License: Proprietary
Upstream has been contacted:
Please see now closed feature request, which was closed prematurely and without care:
NIXOS, similar to Arch offers option (opera.override { proprietaryCodecs = true; }), without this, Opera is pretty much useless as videos won’t play on X (Twitter) and many other platforms.
Consider offering option to include/install opera-ffmpeg-codecs.