Ssr: SSR detects wrong screen resolution when I increase display scale on KDE Plasma X11

Created on 13 Feb 2018 · 12Comments · Source: MaartenBaert/ssr

Hi
I use SSR on Arch Linux running KDE Plasma 5.12.1 under X11.
In KDE settings is configured 1080p as my screen resolution and 1.2 as display scale, but SSR shows 1600x900. See screenshot.
When I set 1 as display scale, SSR shows the correct resolution (1080p).

screenshot_20180213_192743

Source

glaubersm

Most helpful comment

@MaartenBaert, please check this page: http://doc.qt.io/qt-5/highdpi.html
I think you need to set Qt::AA_Use96Dpi in rectangle selection code.

Temporary workaround for users is to run SSR with the following command:
QT_SCREEN_SCALE_FACTORS= simplescreenrecorder

ValdikSS on 28 Jul 2018

👍4

All 12 comments

Interesting. I'm using the standard Qt functions to detect screen layout (QDesktopWidget). What happens when you use the 'record a fixed rectangle' option to enter a rectangle the size of your screen? Does the recording frame that gets displayed have the correct size? Note, the code for drawing the recording frame has changed recently, so it would be best to recompile SSR from source if you want to test this.

Can you also tell me whether your copy of SSR uses Qt 4 or 5? You can see this in the 'about' box.

MaartenBaert on 14 Feb 2018

My SSR (installed from Arch repositories) uses qt5..
Using 'record a fixed rectangle' I can select whole screen but recorded video is 1600x900.

I just installed simplescreenrecorder-qt5-git from AUR but I got the same results.

glaubersm on 14 Feb 2018

I have a similar problem. The resolution of videos I capture from the screen drops to 480p when uploaded with YouTube settings. I could not find the solution.

vdemir on 16 Feb 2018

I know that this is probably not what you're looking for, but have you tried increasing your DPI settings (to make the text in applications bigger) instead of using screen scaling? Because I don't think there's an easy solution for this problem in SSR.

@vdemir If the original video resolution is correct, then that's a YouTube problem, not a bug in SSR.

MaartenBaert on 20 Feb 2018

Increase font scale is a good alternative.
However I hope SSR can work correctly with not default screen scale someday.

glaubersm on 20 Feb 2018

imo it works correctly. If you increase the xrandr scale, you virtually decrease resolution and i'd expect ssr to act exactly as it does. If you want a "higher" Resolution, just increase the video scale in ssr, as the system does. (first calculating the video in the lower Resolution then scaling it to screen size)
I love this feature as it allows me to record an more than 4k video on a PC with an display resolution of 1280x1024. (Display scale 0.25)

QuImUfu on 22 Feb 2018

👍1

Actually the issue also present when choosing "select rectangle". The pixel numbers detected after selecting the rectangle are divided by the desktop scale factor. I have the scale factor set to 2, so I have to manually multiply 4 numbers (left, top, width, height) by 2 to get the correct area recorded.