Ubuntu – How to mirror/flip display output

displaymonitor

For strange reasons best not asked, I have a projector plugged into my computer that is pointed at a mirror. So the computer image is displayed on a wall, but it is mirrored.

In Linux(ubuntu) I can go to display preferences and set the external monitor to have a rotated image. Is there a clever way I could have it set to rotate/flip the image?

Best Answer

Ok after testing with 2 PC. I found the following:

On some integrated cards like Intel you can use xrandr in console. For example:

Go to console (Ctrl+Alt+T)

xrandr -x will flip de video horizontally like a mirror.
xrandr -y will flip de video vertically.
xrandr -y -x will flip both.
xrandr -o normal will return to normal the video.
xrandr -o inverted will...invert O.o

But if you have (in my case) an Nvidia this will most likely not work. For an Nvidia to work you need to:

Edit you xorg.conf: sudo nano /etc/X11/xorg.conf

Finde the section that has Driver "nvidia" in it

Copy and paste the following at the end of that section: Option "RandRRotation" "on"

This will activate the rotation for Nvidia which comes off by default. Why off by default i do not know.

After that reboot and you can change the orientation BUT NOT the reflection. What i mean with this is that Nvidia does not yet support reflection options like -x or -y options in xrandr. I will keep searching for some more since the question is interesting.

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