So, it's no secret i've loved opera since the day i first installed it, I think i joined the opera revolution around the 3.62 mark in 1999 apparently! (man i'm old). Anyhow - read up more about the opera history here https://en.wikipedia.org/wiki/History_of_the_Opera_web_browser
Since i'm this fancy new software developer type person, i have it installed as my browser of choice at work, but we run linux here since the platforms we use are linux as well. I'm not complaining mind you, i like linux too!
But the support for playing videos is lacking :( (wuh waaahhh), I believe this is due to the license with Mpeg's and not being able to distribute the codec with the program.
From this post it appears that Opera doesn't have the rights to distribute the codec with the program. however! Google does (cos they probably have deeper pockets right?)
Anyhow - very easy to fix, we simply copy over the top of the libffmpeg.so that we have in our opera directory with one from the google chromium browser :)
sudo cp /usr/lib/chromium-browser/libffmpeg.so /usr/lib/x86_64-linux-gnu/opera/
Restart the browser and things should be all good again :)