In fractional scaling on X (Cinnamon) if no app in "always on top": when starting and exiting full screen mpv resets display(s) back and forth about mpv HOT 4 CLOSED

Looks like it is related to XRandr scaling. You may try --x11-netwm=no or --x11-bypass-compositor=never.

FWIW, speaking personally, I am strongly against the use of fractional scaling on X.

BTW please attach your log file.

from mpv.

@ruihe774, --x11-bypass-compositor=never (also =no) seems to solve the issue for me (but not --x11-netwm=no). Thank you. I have not noticed any problems with performance and/or quality. What are downsides of this setting?

Would you still like to get log file? Both with setting to no and yes?

from mpv.

I have not noticed any problems with performance and/or quality.

In Cinnamon (and some other DEs), fractional scaling is done using XRandr scaling. For example, if the resolution of your monitor is 1920x1080, and you set the scaling factor to 150%, XRandr will fake its frame buffer to 1280x720 (or 2560x1440 if 2x; I'm not very certain about its behavior). Applications draw to the scaled frame buffer and XRandr then scales the frame buffer to the resolution of your monitor. The scaling algorithm used by XRandr is likely low-quality and can cause blurry text and gamma inaccuracy.

You can check the resolution of the fake frame buffer in mpv. Enter fullscreen and use shift+i. See the "resolution" field in the "display" section.

Would you still like to get log file?

There is nothing mpv can do with this issue. With --x11-bypass-compositor and fullscreen, mpv asks X11 to bypass the compositor. Meanwhile this also bypass the XRandr scaling. The delay is caused by XRandr changing the resolution of its frame buffer.

from mpv.

I believe the above explanation is accurate and indeed there is nothing we can do here. Also, 0.34.1 is not supported anyways. If you are using only one monitor, I would recommend using Xft.dpi instead personally.

from mpv.