Hi! Here is solution for Opera 43. (Kubuntu 16.04 x64)
- We need to update Chromium browser to 56.0.2924.76 version (Opera 43 use this version of Chrome engine)
- Add repository - sudo add-apt-repository ppa:canonical-chromium-builds/stage
- Update system - sudo apt update
- Chromium must updated to 56 version
- As recently as advised tyrion-ua:
Copy the libffmpeg.so file from the library (/usr/lib/chromium-browser)
Replace the libffmpeg.so file in the browser folder (/usr/lib/x86_64-linux-gnu/opera) with this file.
Restart the browser.
Now Opera plays videos from Twitter, Instagram, etc.