I really don’t understand what the full issue is with opera and video codecs, but every few weeks, it will stop playing videos on facebook, twitter and sometimes even youtube. People will surge into the forums to complain and largely be ignored. Here’s what I’ve been able to piece together.
The short reason for the problem is that Opera is based on a slightly time delayed version of Chromium. If the version of Chromium that Opera is using and the version of the libffmpeg.so library don’t match, then problems ensue. [The bit I can’t figure out is why Opera can’t match these up. But moving on …]