Why some games on Linux, SteamOS / Steam Deck have broken videos and what you can do

See a weird pattern of colours when playing some games on Linux / SteamOS and Steam Deck? Some videos not playing? Here's why that happens and how you can fix it. This question actually comes up quite a lot in various support channels so it's time for an explainer.

What am I talking about here? This:

It can perhaps be a little alarming when you're trying to play a game and end up being greeted by this. Or, you might see it in specific places in some games, like where a video should be playing inside a game directly. It's a test card, otherwise known as a test pattern.

This happens when playing Windows games on Linux systems using Proton. The answer as to why is quite simple - it's because those games are using a video codec that is not supported by Proton, which can be due to either technical or legal reasons why Valve cannot support it (proprietary codecs can be messy with licensing).

Shader Pre-Caching

Valve do actually work around it in a lot of cases, where they re-encode the videos into something Proton supports. To actually get those videos downloaded with the game, you need to ensure you have the Shader Pre-Caching system enabled, as it contains game shaders to improve performance and the re-encoded videos too. On Desktop Linux and Desktop Mode on SteamOS it's in the main Steam Downloads settings at the bottom:

The option doesn't appear in Gaming Mode on SteamOS, since you're not really supposed to turn it off.

GE-Proton

If that doesn't fix it after ensuring it's enabled, the other option you can try is GE-Proton. Since it's a community build of Proton, it doesn't exactly have to follow all the same rules as Valve. GE-Proton does include some extras to get videos in a bunch of specific games working. We have a GamingOnLinux guide to setting up GE-Proton and usually GE-Proton will fix it, but not always.

Speaking to the developer of the game in question is always a good idea too, ask them to see if they can use a more open codec for their videos so it will work across more systems.