Hi,

i have a 4k 28" monitor - so the viewable area is effectively 4 1080p monitor.

I also like to multitask, so I would like to be working on my monitor, while i watch say a video.

I was then wondering if there was anyway to "fake" fullscreen, for an app (i.e. convince it to go to full screen mode in a window about 1080p), thus creating a much larger video to view, but not taking up the "real" fullscreen. While some video streamers (like youtube, have several different modes that help, many don't, they have a binary choice, either a small video window, or full screen.

i currently use lxqt on openbox

thanks
c

I don't know of one.

In linux terms solid state monitors/screens are new. Software was developed on CRT monitors. Over-scan beyond certain limits was dangerous on those beasts, leading to over-voltage in the Line OutPut Transformers, overbrightness, and expensive component failure. You can usually stretch a small screen manually, or often set the default window size depending on the app.

I've had to run a few things in a Xephyr window to do that. Like streaming a webcam video with VLC. Or other SDR python things that fail for resolutions > 1024x1024. It's basically running another X session in your current X. But you'll likely lose any GPU accelerations in the Xephyr window. I've also used Xephyr + Xdmx to have 4 windows make a really long xterm session. I can fit the entire hier manpage on a single 1080p screen doing that. Caveats of course like running an xterm assigned to that session to set DISPLAY and launch the application.

$ Xephyr :11 -screen 1920x1080 -title Xephyr11
$ xterm -display :11
...in the Xephyr session...
$ export DISPLAY=":11"
$ mpv -fs myvideo.mp4

Other caveats of course like not being able to cut and paste from your default X session into the Xephyr session.

1 members found this post helpful.

Is it possible that the graphics card configuration will allow this? I know the NVIDIA one allows a lot of options but, not having a huge 4K screen, I've not looked at seperating screens in such a way.

Shadow 7, Shad, my man! (can i call you shad?)

Thanks, this is brilliant - not exactly what i want, but it is way better than what i have. There is no window manager in the Xephyr window so the window launched in there was a bit of a hassle (coming up with it's default size and ironically with no window manager, fullscreen only would take up the window size, not the "screen size", which might lead me further along for a different solution in the "normal desktop" X display.

Setup, same as your really
$ Xephyr :11 -screen 1920x1080 -title "Xephyr on 11"
$ export DISPLAY=:11

In the end - this command line for chrome works great
$ google-chrome --window-size=1920,1080 --window-position=0,0

This enabled me to watch nbcsports gold (to watch the UCI world cup mountain bike world championships) in the 1920x1080 Xephyr window, fullscreened in chrome, but obviously not taking up the whole 4k monitor (just the Xephyr window) - so i can multi-task (poorly) on the rest of the 4k screen (like typing this response).

The video seemed to go pretty well at 1080p, some tearing, but very, very watch-able

thanks mate - once again, this is fantastic.

One other quirk, Cntrl+Shift locks your input into the Xephyr session. And unlocks it. You can run a DE in the Xephyr, but you have to launch it from the xterm. Bear in mind that each layer is more processing and less CPU resources for other tasks. I tend to use no spaces in the title so it's easier to position things with wmctrl.

$ wmctrl -r Xephyr11 -e 0,0,0,1920,1080

Would put it top left. For non-top+left be sure to compensate for the window decorations. Xephyr is kind of meant to test odd resolution cell phone type apps. With an ancestor of sorts, Xnest, that does basically the same thing.