asleeponduty: Unity asset bundles are compiled differently for Linux and Windows. Implementing a system to convert this stuff at runtime in the game is nonsensical. VRChat has been pretty supportive of Proton, and some members of the dev team use Linux on the daily and understand this too.

I wrote further on this in other replies on this post, please feel free to check those out. I will say, Proton video support is actively being worked on. But work from the AVPro team will have to be done as well for streams to function properly.

TL;DR Proton > Native in this case.

ZarathustraDK: That is NOT the issue. If you run VRChat's provided build of yt-dlp in the wineprefix for the game, it returns URLs perfectly fine.

The problem is down to Windows Media Foundation support. When you build a game in Unity, it makes video players use the platform's native multimedia rendering capabilities, so on Windows that's WMF. The problem is WMF is a cesspool of proprietary code and Proton developers are still slowly figuring it out after many years.

As a result, developers have disabled AVPro when the game detects that the running environment is Wine/Proton. Unity native video players are still technically enabled because they just fail gracefully instead of crashing the whole game.

You can't make a Linux native build of the game because it would be incompatible with Windows avatar and world assets, and there would be a similar divide in content as there is with Quest. And even if you were to include DXVK-Native into the Linux build, all the bits of content that isn't shader/texture stuff would simply not work.

The best option for VRChat is to wait for Proton to implement working WMF video playback. (Valve, Collabora, Please.) and once that happens, non-stream Unity native players should work right away, and then the developers can start testing again if AVPro works or not and remove the Wine/Proton checks if it's successful.

Check the issue for VRChat on the Proton GitHub repository if you want to follow development day-to-day. https://github.com/ValveSoftware/Proton/issues/1199

AuroraNemoia: Pretty sure WMF has been fixed on proton-ge iirc. Would be nice if VRC would check for the proton version and allow youtube-dlp to run if found.

Did they remove the check?

I decided to switch out my test to try to use native YT-DLP to the old one again and VRChat crashed immediately after trying to play the video, which suggests that it tries to load but is not fully compatible yet. I see reports of it crashing if manually enabled with --enable-avpro-in-proton, yet, it does crash for me even though I did not enable that flag. Maybe it was just a coincidence; I only tested once.

After further testing in Video Player Showroom (https://vrchat.com/home/world/wrld_985acb34-cc17-4b5a-85ae-04ade5195059), it appears that the Unity default video player works fine (running a HEAD request on normal, when I test with my own server), but the AVPro-based one crashes VRChat. Interesting. This occurs with the 1080p 60 fps version of Big Buck Bunny, bbb_sunflower_1080p_60fps_normal.mp4, hosted on my own server so that I can log requests. I am guessing the --enable-avpro-in-proton command is a Unity option specific to the Unity video player, but this does not explain why it crashes now when it never did before. Maybe it is because it is partly working now, but not enough to not be buggy?

ForeverAndaDay: In Proton Experimental the video player is still not working.