Why don't you just install chromium-codecs-ffmpeg and chromium-codecs-ffmpeg-extra since you are on ubuntu? And please remove the oxideqt-codecs and oxideqt-codecs-extra you seem to have installed...

You cannot install both "chromium-codecs-ffmpeg" and "chromium-codecs-ffmpeg-extra" at the same time. The latter includes everything from the former and some additional codecs. However, as I pointed out in another thread, everyone had already had "chromium-codecs-ffmpeg-extra" installed when Twitter videos stopped playing, so it wasn't their lack that caused the problem.

Right now, christophffm's is the only solution that works.

@zhochaka That's why it is useful to understand the root of the problem. If you read the old @jimunderscorep's post, you will see that the problem is that the new version of the codecs is not yet in the Ubuntu repo. Since the repo is not maintained by Opera developers, there is no reason to blame them. In my opinion, Opera shouldn't release a new version to the stable channel until necessary codecs arrive, but this is an operational problem and has nothing to do with the quality of the product itself.

Similarly, although obtaining a new version of libffmpeg and copying it manually might work, it is not a good solution. However, if we take into account that Opera 54 was released to the channel too early (relative to codecs), the logical solution is to roll back Opera itself and put it on hold until the Ubuntu team pushes new libffmpeg to their repo, and this was exactly what I did 2 weeks ago and described in this post:

https://forums.opera.com/post/149314

Now that a new version of chromium-codecs-ffmpeg-extra is finally in the Ubuntu repo, it's time to unhold opera-stable and do an upgrade. I just did what I suggest in the above post, and Twitter videos work fine (and why wouldn't they?). You can always check that you have version 67 of chromium-codecs-ffmpeg-extra with the following:

$ dpkg -s chromium-codecs-ffmpeg-extra
Package: chromium-codecs-ffmpeg-extra
Status: install ok installed
Priority: optional
Section: web
Installed-Size: 4050
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Architecture: amd64
Source: chromium-browser
Version: 67.0.3396.99-0ubuntu0.16.04.2

@melangecounselling
If Opera 55 is based on Chromium 68, you'll likely need chromium-codecs-ffmpeg-extra version 68. Can you check what version you have currently installed?

@jimunderscorep Thanks! I just looked at Vivaldi's dependencies. They also include chromium-codecs-ffmpeg-extra as a recommended dependency, just as opera-stable does. However, the version from the repository plays Twitter videos without problems. According to its "About" window, the browser is based on ancient Chrome 65 and yet it somehow manages to use the latest (68) codecs. What's the trick? )

Thank you for the hint. It works now if you copy
libffmpeg.so
from
/usr/lib/x86_64-linux-gnu/oxide-qt/
to
/usr/lib/x86_64-linux-gnu/opera
with Ubuntu 14.04 LTS.
Sorry for being so upset. But if you want regular people to use this software then this "workaround" is already too much. Cause Opera is a excellent piece of software and if many people use it, it will be maintained in the future.

Cool! I have no idea why overwriting the newer version of libffmpeg.so with the old one works, but it solves the problem.

@vgharris Your problem reminds me of what I experienced a couple of years ago and described in this topic:
https://forums.opera.com/topic/26795/getting-logged-out-from-twitter-etc
You can try the solution from the third post and see how it goes.

I checked other browsers, and it seems that this regression comes from Chromium. Both latest versions of Chromium, Opera and Vivaldi are affected. Take a look at the screenshot (left - Firefox, right - Chromium 83):

The same goes for all images, internal PDF viewers, favicons, icons in menus etc.

I'm also on 20.04 Ubuntu, a different flavour.
It's not just the font that got smaller: all rendering is complete rubbish in 69. Just look at the AdBlock icon in the extension bar.
Also the PDF viewer renders everything as blur compared to a standalone PDF reader.

@jimunderscorep Vivaldi is not Electron-based. Brave is Electron-based, but Vivaldi is Qt-based, just like Opera. It is definitely slower than Opera though, not sure why.

@s4n-op You don't actually need to copy anything. As long as the installed Opera version is compatible with the installed Chromium codecs, everything works fine (except Netflix or Stan, but that's a different story).

@jimunderscorep Thanks! I just looked at Vivaldi's dependencies. They also include chromium-codecs-ffmpeg-extra as a recommended dependency, just as opera-stable does. However, the version from the repository plays Twitter videos without problems. According to its "About" window, the browser is based on ancient Chrome 65 and yet it somehow manages to use the latest (68) codecs. What's the trick? )

@jimunderscorep Yeah, I checked that today and updated both the codecs and the browser. Works perfectly. It seems that putting chromium-codecs-ffmpeg-extra and opera-stable on hold until both updates are definitely in sync is the most surefire way to never break video support.

Very interesting info on other distributions! Could you also explain why other Chromium-based browsers are different? As far as I know, Vivaldi is also based on Chromium and uses Chromium codecs, but its support for HTML5 video rarely breaks.

@messweb You should check the version of chromium-codecs-ffmpeg-extra. Since you're using Opera 54, which is based on Chrome 67, you need to make sure that the codecs are also at version 67.

@leocg Interesting idea, but I'm not sure how packaging Opera snaps is going to help with codec issues. As far as I understand it's still Canonical who publishes codec snaps, and Opera still has no control when it happens.

@jimunderscorep Seems like Ubuntu developers already pushed version 68 to the repository. I've just checked it:

$ apt-cache policy chromium-codecs-ffmpeg-extra
chromium-codecs-ffmpeg-extra:
  Installed: 67.0.3396.99-0ubuntu0.16.04.2
  Candidate: 68.0.3440.75-0ubuntu0.16.04.1

Putting it on hold until a new Opera (version 55) is released:

$ sudo apt-mark hold chromium-codecs-ffmpeg-extra

@skirual This is pretty strange. As far as I know, Opera repositories are maintained by Opera, not Ubuntu. Opera 53 was compatible with codecs 66, and Opera 54 is compatible with codecs 67 (both are in repositories for Ubuntu 16.04 now and work well). Probably Opera devs forgot to push a new version to the repo?

You can try downloading Opera 54 manually from here:
https://get.geo.opera.com/pub/opera/desktop/54.0.2952.64/linux/

@melangecounselling
If Opera 55 is based on Chromium 68, you'll likely need chromium-codecs-ffmpeg-extra version 68. Can you check what version you have currently installed?