Advice for presenters

This is the reference documentation for advice for presenters for events recorded by the DebConf video team. If you think something should be included here, don’t hesitate to Contact us or to make a merge request on the git repository for this documentation.

All event-related advice should instead be added on their respective wiki page.

Display Output

We use a 16:9 resolution, 1280x720. Our old limitation of 1024x768 resolution and 4:3 aspect ratio no longer applies. Slides that have a 4:3 aspect ratio will be pillar-boxed. This means if your presentation is not 16:9, it will be displayed between black bars.

Our video capture system uses HDMI. The video team has adaptors to some other formats:

  • micro-HDMI

  • mini-HDMI

  • DVI

  • DP

  • mini-DP

  • USB-C (thunderbolt compatible)

  • VGA (best-effort, via unreliable adapters)

The VGA-to-HDMI adapters are on a best-effort basis. Those are known to be somewhat unreliable and you are encouraged to test your laptop with them prior to your talk, in order to check whether they are an option.

If your laptop doesn’t have one of the above mentioned digital ports, it’s up to you to bring an adapter and, ideally, test it before bringing it to DebConf.

Presenters are strongly encouraged to test if their setup works correctly with our video equipment before their session, either in one of the video team volunteer training sessions or in breaks between talks. Attempting to fix stuff five minutes before your presentation is not fun!

As a last resort, desktop systems are present as part of the videoteam setup, so if you have your talk in PDF format, it can be presented via the desktop system.


If your USB-C port uses Thunderbolt, you may need to update your thunderbolt firmware to get video to work.

xrandr hints

720p VGA mode

One of these should work to get 720p video over VGA:

xrandr --newmode 720p60 74.25  1280 1390 1430 1650 720 725 730 750 +HSync +VSync
xrandr --newmode 720p60-2 74.25 1280 1392 1448 1650 720 722 728 750

Substitute the mode that works better appropriately in:

xrandr --addmode VGA-1 720p60
xrandr --output VGA-1 --mode 720p60

This should make VGA only laptops work with the Opsis capture board using a VGA-to-HDMI adaptor.

Mirroring at non-native LCD resolution

This should work:

xrandr --output LVDS-1 --scale-from 1280x720 --output HDMI-1 --same-as LVDS-1

Publishing your slides

Please publish your slides in the appropriate DebConf share repository.

Alternatively you can email your presentation the videoteam mailing list and it will be added to the repository (eventually).


Debian presentation templates for various architectures, and archives of previous talks can be found on the main Debian wiki.


To get your slides to the right aspect ratio, you can use this snippet in your beamer template:



If possible, bring something to drink during the talk. We normally try to have water bottles at the speaker’s desk, but can’t guarantee anything.