@trawglodyte :-
Mm.....there's a wee bit more to the "libffmpeg.so thing" than ya realize.
Fredx181 started the ball rolling with all these portable Puppy apps 5 or 6 years ago, with a portable version of mainline Firefox. My own very first attempt at these - following Fred's method - was a portable build of PaleMoon. Having found success with that, I then did a portable build of Thunderbird. Then, it was time to turn my attention to the Chromium 'clones'.
I've used Chrome since day 1, all the way back in the autumn of 2008. My ultimate aim was always to create a Puppy 'portable' build of Chrome itself; as it turned out, it was pretty much the last one I created.....having "learnt the craft" through building several others before I got around to Chrome itself!
One thing you soon learn about with the Chromium-based browsers (and even Chrome itself is simply a 'clone' of Chromium, albeit with Google's proprietary stuff added in), and that is this; IF you want audio/video stuff in any of the clones, you soon learn about libffmpeg.....because they require a build of libffmpeg to run at all. Some have it as a separate component; others, like Google, actually build it into the main shared library when they re-compile the source code themselves. That's why you can't see libffmpeg.so anywhere in Chrome; it's there, but it's 'built-in'.
Libffmpeg.so gets re-compiled for every major release of Chromium by various folks who host their builds on Github. Only subtle differences between builds, but often enough to prevent the browser from playing-back audio & video......sometimes, even from launching in the first place. If you've been using the same version for a long time, you've been extraordinarily lucky, 'cos it doesn't normally work like that.
Opera was my first 'portable' Chromium-based 'clone'.......and, I soon discovered, one of the fussiest. The 'lib_extra' directory is built-in to the 'opera' main directory, and the 'LAUNCH' script tells it where to find it. One of our veteran members - seaside - figured-out that a couple of files in the 'resources' sub-directory also needed tweaking to point things to the right location. And Opera themselves officially approve only ONE specific individual's libffmpeg.so builds for their browser......and go so far as to warn you that other builds probably won't work.
They're right, too. They won't.
Unless you regularly read/lurk around/join up to the Opera community forums, you'll never learn about this stuff. Modifying/re-building the 'clones' is a lot different to the 'zilla-based browsers. Firefox & co. are simple to work on compared to Chromium & the 'clones'.....
Mike.