Mirroring to a Projector From Linux


This description worked perfectly for me: http://main.linuxfocus.org/~guido/linux-x11-xrandr-presentation-on-projector/

From my 2018 model Dell XPS 13 with HiDPI screen, running the pre-installed Ubuntu distribution (16.04), in the “Innsikt” room at Teknologihuset I got great results with the following command.

  xrandr --output eDP1 --scale 0.5000x0.5000 --mode 3840x2160 \
         --output DP2 --mode 1920x1080 --same-as eDP1

In any other context YMMV, I present this with no guarantees.

The long version

While I’m reasonably comfortable running Linux on the desktop these days, connecting to a projector has always been a challenge until yesterday, when I finally found the right link on the internet to explain what I needed.

While I’m a happy casual user of Linux on the desktop, I’ve never managed to learn what I needed to really hack around common problems when connecting to projectors. Over the years connecting monitors directly has become a lot easier than my first experiences with Fedora approaching 20 years ago and until recently I’ve been using a MacBook in order to avoid dealing with such issues.

When changing jobs in 2017, I was getting frustrated with annoying window management “features” in OS X, and was jealous of co-workers running i3 so decided to order an XPS 13 with linux pre-installed as my official work machine.

The experience has been mostly painless but when presenting at an internal event I decided to try connecting to the projector from my XPS and ended up with bad resolution on the projector with the contents being mirrored to the top left corner of the screen on the laptop, not much use.

Wise from experience I had also packed my Chromebook and was able to present with that. Last night I was going to present a little at the Oslo Rust meetup in the same room and same projector as before. I decided to do my homework this time.

After surprisingly little googling I came across a page that looked promising;


I turned up early to the meetup in order to play around with the settings and landed quickly on a configuration that worked for me. Regrettably I didn’t keep my shell output so that I could document the whole process but the command at the top of the post is what I landed on. Looking at things on the laptop screen things looked a little chunky, especially the address bar in Chrome and UI of IntelliJ IDEA but the representation on the projector was, in my opinion, perfect.

Thanks for the great instructions Guido!