[Issue/Bug] Jittery video

[sophisma]

Is there an existing issue for this?

• I have searched the existing issues

Is this issue has already been addressed in documentation?

• I have read the readme file

Describe the bug/issue

Hi.
I installed PhoneVR v2.0.0-beta on my phone and ALVR server v20.9.1 on my PC.
I'm having issues with jittery video on SteamVR and games (Falcon BMS, is the only game I tried so far).

A few extra information.
I'm using a POCO F3 with HyperOS 1.0.2.0.TKHEUXM (latest official OS version for the phone).
I'm on a 5Ghz wifi network without any other traffic going on.
I tried every setting I could find in ALVR Dashboard, from refresh rates (60Hz/120Hz) to encoder preset (Speed/Quality) to bitrate (5Mbps/30Mbps), and basically all other settings just to see if it changed anything, but nothing worked.
E reverted everything back to default and recorded two videos showing this.
The first video is in SteamVR, this one is hard to see because the recording is too dark, but it's definitely there.

https://www.youtube.com/watch?v=ONBRTbgbXn8

The second video is in Falcon BMS and it's a lot easier to see it happening.

https://youtu.be/FUobTHbwSuU

Can you suggest something to try so that I can fix this?

Local (your) Time when Issue has occurred

15-Aug-2024

How To Reproduce your issue

Install PhoneVR on the phone and SteamVR and ALVR Server on your pc and use default settings.

Expected behaviour

Video should play smoothly.

Screenshots

I posted videos showing this before but here they are again, unfortunately they look a little dark.

https://www.youtube.com/watch?v=ONBRTbgbXn8

https://youtu.be/FUobTHbwSuU

Environment (please complete the following information)

Desktop OS: Windows 10 - Ryzen 7 7700 - 64GB RAM - GTX 1060 6GB
Android OS: HyperOS 1.0.2.0.TKHEUXM (Xiaomi official OS)
Mobile Device Model: Poco F3
ALVR Version: v20.9.1
PhoneVR Version: v2.0.0-beta

Additional context

No response

Attached Logs

No response

[ShootingKing-AM]

How about you try the v20.8.0 version ALVR Server ?

[sophisma]

Sorry, I should've read the instructions a bit more carefully, you're very specific about the suported ALVR version.
Unfortunately it does the same thing.

[RoverBot-Dev]

I have a similar issue except the video stream doesnt show up on my phone. The tracking works tho
Update: i changed some settings including setting headset type to vive (dont know which setting fixed the video not showing up) but i get the same issue, very bad stuttering..

[Nemozxy]

I ran into the same problem, again with HyperOS. The whole picture shakes so much that it's almost unusable.

[SebastianGode]

This is an hardware issue of your PC.
In the statistics tab check whether "Client FPS" and "Streamer FPS" are matched.
With the jittery video I assume that isn't the case and "Streamer FPS" is way lower. This means that your PC is unable to generate images fast enough and the interpolation of the client then causes this jittery video. Reduce the graphics settings of your game to the point where both framerates are identical again.

Be aware that you need beefy hardware for two 1440p (or higher) streams! Twice the power as you'd typically need for normal playing.

[sophisma]

This is an hardware issue of your PC. In the statistics tab check whether "Client FPS" and "Streamer FPS" are matched. With the jittery video I assume that isn't the case and "Streamer FPS" is way lower. This means that your PC is unable to generate images fast enough and the interpolation of the client then causes this jittery video. Reduce the graphics settings of your game to the point where both framerates are identical again.

Be aware that you need beefy hardware for two 1440p (or higher) streams! Twice the power as you'd typically need for normal playing.

That was happening even on the SteamVR "room", even before the game (Falcon BMS).
I don't think the PC is the issue, the game has fairly old graphics and didn't have any fps drop at all at 1080p.
I won't be able to check Client FPS and Streamer FPS at the moment, I have to reinstall everything.

[SebastianGode]

You know that on normal phones you are running 2x 1440p, right?
That's literally 4x the GPU power which you need compared to your 1080p monitor. Additionally you likely set the refresh rate to 120fps or so.

If you get 120fps on 1080p on your monitor don't expect more than 30fps in VR at native resolution. You can set the scaling to 0.5x for example and try if it's better.

In Elite Dangerous I'm typically playing with ~100fps in 4k with my 4070Ti Super on Ultra. With VR I need to go down to Medium to reach ~90fps which I need.

[sophisma]

I remember trying it at 60Hz and other resolutions and having the same issue.
I changed every option on the server and on Steam VR
No matter what I did it always had that.
The only thing I haven't tried was using a usb cable, I always used it wirelessly.

[EdLovecraft]

How do I fix this? Old frames keep flashing back and making the program basically unusable

[SebastianGode]

@EdLovecraft
You need a faster GPU. That only happens if your PC is unable to render the selected fps.

[sophisma]

@EdLovecraft You need a faster GPU. That only happens if your PC is unable to render the selected fps.

I don't know if that's exactly correct, my pc was rendering the game at 140fps, it should handle 60fps in VR without issues.

[EdLovecraft]

@EdLovecraft You need a faster GPU. That only happens if your PC is unable to render the selected fps.

I believe it's an issue with the PhoneVR client or an older version of ALVR, I tried the latest version of ALVR and the ALVR client and the video has no jittery issue. However, in the latest version of ALVR, there is an issue where the entire viewpoint gradually drifts toward the upper left over time, and even recentering cannot fix the issue.

EDIT: I've noticed that with ALVR v20.8.0 the client FPS constantly bounces between 60 and 120 quickly, while with the latest version of ALVR and the ALVR client the client FPS basically stays at 120FPS