Virtual Display does not work on Linux

[jefferyrlc]

Problem:
Setting up Apollo to always create a virtual display does nothing on my system.

Expected:
A virtual display appears in my list of screens.

System:
Apollo 0.4.6
KDE Plasma (Kwin Wayland) 6.4.5
Wayland Protocols 1.45
Linux-zen 6.17
AMD RX 6800
Mesa 25.2.4

It looks like SudoVDA isn't available on Linux. Not sure how one would work around this.

[kayti]

From what I remember, Linux is not supported by Apollo. Precisely because of the lack of universal VD solutions.

[jefferyrlc]

Shot in the dark here, but this looks promising: https://github.com/DisplayLink/evdi

[ClassicOldSong]

Linux does not provide a universal and performant way to create virtual displays like on Windows.

Curious how you can even get it compiled on Linux but ignored the basic that virtual display doesn't work...

I don't provide pre compiled Linux binaries for a reason.

[skhtor]

The Linux market is growing quite rapidly, hopefully soon enough the great community builds out the tools necessary to make this easy enough to implement.

Love your work @ClassicOldSong. I run Linux now and quite literally the only thing that is making me go "damn, Windows did this better" is Apollo

[colelisiongaming]

@ClassicOldSong Would what @jefferyrlc posted work? https://github.com/DisplayLink/evdi

[ClassicOldSong]

Not really. I don't have time to test it, but at a glance it can't utilize GPU resources. All its frame buffer exists on the RAM instead of VRAM, that means it can't do complicated graphical rendering.

DisplayLink/evdi#422

This issue confirms it

[colelisiongaming]

Not really. I don't have time to test it, but at a glance it can't utilize GPU resources. All its frame buffer exists on the RAM instead of VRAM, that means it can't do complicated graphical rendering.

DisplayLink/evdi#422

This issue confirms it

Alright well thank you for looking into it. Much like other users this is the last thing before I could delete windows. Wonder if I could do a script or something with my HDMI dummy dongle or something in the meantime. The only issue is the HDMI dummy dongles on the market don't support weird aspect ratios only 16:9 I believe. So my 16:10 steam deck and 3:2 framework are out of luck.
Let me know if you think this might work, regardless thank you for your work in the community. My pregnant wife thanks you as she can play games in bed now.

[alexballas]

Alright well thank you for looking into it. Much like other users this is the last thing before I could delete windows. Wonder if I could do a script or something with my HDMI dummy dongle or something in the meantime. The only issue is the HDMI dummy dongles on the market don't support weird aspect ratios only 16:9 I believe. So my 16:10 steam deck and 3:2 framework are out of luck. Let me know if you think this might work, regardless thank you for your work in the community. My pregnant wife thanks you as she can play games in bed now.

It's a bit of a weird situation indeed. Couple of months ago I bought a JetKVM to remotely control my Linux desktop. Interestengly enough JetKVM allows me to set custom EDID values or use one of the predefined ones and offers a range or resolutions and aspect ratios (unfortunately not 3:2). JetKVM acts a monitor so It can be used with Apollo or Sunshine.

JetKVM is just an example. On Linux you could potentially be able to force a custom EDID to your dummy plug and unlock more resolutions.

This EDID for example includes the 1280x800 SteamDeck resolution.
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

There are various guides online on how the EDID forcing process works.

[colelisiongaming]

Alright well thank you for looking into it. Much like other users this is the last thing before I could delete windows. Wonder if I could do a script or something with my HDMI dummy dongle or something in the meantime. The only issue is the HDMI dummy dongles on the market don't support weird aspect ratios only 16:9 I believe. So my 16:10 steam deck and 3:2 framework are out of luck. Let me know if you think this might work, regardless thank you for your work in the community. My pregnant wife thanks you as she can play games in bed now.

It's a bit of a weird situation indeed. Couple of months ago I bought a JetKVM to remotely control my Linux desktop. Interestengly enough JetKVM allows me to set custom EDID values or use one of the predefined ones and offers a range or resolutions and aspect ratios (unfortunately not 3:2). JetKVM acts a monitor so It can be used with Apollo or Sunshine.

JetKVM is just an example. On Linux you could potentially be able to force a custom EDID to your dummy plug and unlock more resolutions.

This EDID for example includes the 1280x800 SteamDeck resolution.
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

There are various guides online on how the EDID forcing process works.

That is amazing it allows you to do that I never saw that while researching. My current issue is my HDMI dummy plug only outputs max 4k60 even though I get 4k120 on windows I suppose this is a HDMI 2.1 support issue. I was thinking of getting a displayport dummy plug but high resolution ones don't exist so HDMI to displayport active adapter looks like the way to go.

[MrOz59]

I made this version in my free time using mostly AI. It's probably not 100% functional for everyone, so I won't send a pull request, but for anyone who wants to take a look at how the AI ​​implemented EVDI, I tested it with Artemis and it seems to work for me. I didn't do any extensive testing, but at first glance it seems to work. I tested it on CachyOS.

https://github.com/MrOz59/Apollo-Linux

[ruifung]

Oh? EVDI works for this? Have you briefly tested it with any games yet?

Because if this works, I will be reassessing my dependence on windows for my primary workstation.

[ruifung]

Not really. I don't have time to test it, but at a glance it can't utilize GPU resources. All its frame buffer exists on the RAM instead of VRAM, that means it can't do complicated graphical rendering.

DisplayLink/evdi#422

This issue confirms it

I just realized one thing about that linked issue. The comment seems to be about video stream encoding, not application rendering.

I'm personally, looking forward to doing some tests with that fork that did EVDI support.

[MrOz59]

Oh? EVDI works for this? Have you briefly tested it with any games yet?

Because if this works, I will be reassessing my dependence on windows for my primary workstation.

I didn't test it thoroughly, but initially it seemed to work. I did it mainly to test Opus 4.5 and see how far it could go, but no extensive testing was done. I just connected and started a game, that's all. I don't think it can be used in its current state to make any kind of update for Apollo, but it can serve as an example, although I can't say if it was implemented in the best way.

[Nycz-lab]

@MrOz59 ive looked through the commit and it seems okay to me. A few improvements would be to link the edvi library during the build process instead of dynamically registering the functions at runtime and a few minor issues. Id be interested in working on a PR for this, @ruifung as far as im concerned the issue with evdi is just the absence of gpu compression support? I havent tested it yet myself but this is probably still the best option we have currently for virtual displays on linux