Window Capture experiences periodic stuttering when a Window Portal has been shared

[deadmeu]

Operating System Info

Other

Other OS

Arch Linux

OBS Studio Version

29.1.2

OBS Studio Version (Other)

Flatpak

OBS Studio Log URL

https://obsproject.com/logs/ImHm40OqaOaFNWBM

OBS Studio Crash Log URL

No response

Expected Behavior

Window Capture should not have periodic stuttering when a Window is being captured.

Current Behavior

Using a Window Capture source, when a portal is shared with OBS I begin to experience stuttering every second. If I open OBS and no portal is shared (and the sharing popup opens) I do not experience any stuttering.

Steps to Reproduce

1. Create a Window Capture source
2. Select a window to share from the Screen Sharing Portal and share it
3. Observe a periodic lag spike occurring every second

Anything else we should know?

This seems to be a Flatpak/Wayland issue and could potentially be an issue with the portal provider (although I don't know much about that) rather than with OBS.

Additionally, it seems like if I have OBS running for a while without sharing a window, or by changing the shared window, it sometimes seems to fix the issue and the stuttering stops even while the window is being shared (though I cannot reliably reproduce this). Restarting OBS causes the stutter to begin once again.

[GeorgesStavracas]

It's not entirely clear from this issue what is stuttering. Is it OBS Studio that sttutters? Is it your stream? Or is it your entire desktop?

[deadmeu]

It's not entirely clear from this issue what is stuttering. Is it OBS Studio that sttutters? Is it your stream? Or is it your entire desktop?

It's my entire desktop. Everything including my cursor.

Here's an example:
https://github.com/obsproject/obs-studio/assets/12111013/aac4be2b-d4db-4c02-8139-6a05079f162a

Before I share a window I get a consistent 144 fps, but as soon as I begin sharing a window it begins to periodically stutter, causing the fps count to go down to about 138 (on average).

[deadmeu]

Here's a better example with some basic frame timings:

better-ufo-screen-test.mp4

[GeorgesStavracas]

Thanks. It's clear from the recordings that your entire desktop is lagging, that's very likely to be a problem in your compositor (seems like it's KDE's kwin? ). OBS Studio does not influence the performance of the compositor, it merely requests a screencast and receives the frames. There is nothing we can do about it on OBS Studio side. Please report this to your desktop environment.

[ghost]

@deadmeu Did you create a bug in the KDE bug tracker as I'm running into this issue myself.

[deadmeu]

@deadmeu Did you create a bug in the KDE bug tracker as I'm running into this issue myself.

Yes I did https://bugs.kde.org/show_bug.cgi?id=471364