How to do I duplicate my desktop with projector using xrandr?

e11i0t · 2019-08-31 06:16:05

Hello, I am trying to duplicate my desktop with projector but I am getting some weird results.
Here is the result of my xrandr --current

 
xrandr --current
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
LVDS-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1366x768      59.97*+
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   640x400       59.88    59.98  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
VGA-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 connected (normal left inverted right x axis y axis)
   1024x768      70.07 +  85.00    75.03    60.00  
   1920x1080     60.00    59.94  
   1600x1200     60.00  
   1280x1024     85.02    75.02  
   1280x960      85.00  
   1152x864      75.00  
   1280x720      60.00    59.94  
   1024x768i     86.96  
   832x624       74.55  
   800x600       85.06    72.19    75.00    60.32    56.25  
   720x480       60.00    59.94    59.94  
   640x480       85.01    75.00    72.81    66.67    60.00    59.94  
   720x400       87.85    70.08  
   640x360       70.08  
DP-1 disconnected (normal left inverted right x axis y axis)

I tried

$ xrandr --output HDMI-1 --same-as LVDS-1

I also tried using arandr my result on projector is good, but my desktop screen cuts in half

seth · 2019-08-31 07:24:11

The LVDS is running at 1366x768, a resolution not supported by the HDMI (the projector seems XGA, what is fairly typical)
You could try "xrandr --output HDMI-1 --auto --scale 1.3334x1" what will run the projector at XGA but squeeze the 1366 width into it. If the projector has an image scaling feature, you could then stretch the image to restore the aspect.

Otherwise you'll simply have to drive both outputs at XGA.

* There's also a generic transformation matrix which would allow you to shrink the output, preserving the aspect and just leaving some area dark, but that's not supported by all drivers (the same way or "at all") - I can tell you that the nvidia blob has an easy to use viewport mapping feature in nvidia-settings, which does work

Arch Linux

#1 2019-08-31 06:16:05

How to do I duplicate my desktop with projector using xrandr?

#2 2019-08-31 07:24:11

Re: How to do I duplicate my desktop with projector using xrandr?

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