I'm not sure I understand what you mean about browser tabs. This pops the video outside of the browser's chrome, so you can drag it wherever you want.

They implemented it in Firefox because Firefox is the one detecting and playing the video? MacOS already has a similar feature, but AFAIK it only works in Safari.

I mean it's limited to content managed by the browser, whereas the native WM way works for all apps.

I guess I don't know enough about how WMs work. :(

I'm curious how the WM could detect that the a portion of a window is playing video, and break that out into it's own movable window?

I'm not sure how you do that without the browser managing that.

But you don't want it to be limited to plain video players - videoconferencing apps, games, and various real-time data displays etc are good fits to pip too. You are able to pipify any window without the app having to explicitly support it.

I think the main point of this feature is that it breaks the video out from a window in the existing page.

I can then interact with that video separately from the page. I can scroll around on the page, I can open other links. It decouples the video from the page.

There's lots of ways to open new chromeless window, or set a window always-on-top. That totally makes sense to be in a wm, but that's not all this is doing, right?

It can't. (on some platforms, the video ends up on a compositor subsurface, but so can many other portions of an app so trying to make a PiP feature out of that would probably not work well)

Right. It should send the stream to the system video player. If you then want no window decorations or whatever you go to the video player app developers.

This pops out the <video> element, so it works on 100% of websites with one. You can use tools like youtube-dl to extract/convert a lot of websites' video to a playlist compatible with external players, but it will never have as complete coverage.

or use https://mpv.io/ which will use ytdl internally to 'just play the fkn vid from the url' kthxby

The PIP video is independent of the browser window that contained the video -- it can be moved around the desktop and resized with no window decorations and also stays on top of all other windows in the desktop env.

It is still pretty dependent on that browser tab. Accidentally close that tab, there goes your video. You also lose controls like scrubbing, and can only PiP one video at a time.

If you don’t like window decorations (and I don’t blame you) just run a wm with no window decorations (like cwm.)

there's a lot of firefox users that don't want to switch to a new window manager (or operating system) just for the sake of being able to pop a video out of the window it came from.

This makes sense on one hand, but could also be used to justify all kinds of of non browser features that would make both WMs and FF worse off in the long run.

In this case, I think "limited to" means available with, not rendered inside of.

But can't be used for other apps like video players or videoconferencing apps.