2024551 - Flickering / unstable rendering when gfx.wayland.hdr is enabled

Status: UNCONFIRMED

(Core :: Widget: Gtk, defect)

Description

[Siddh Raman Pant]

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36

Steps to reproduce:

• Install 140.8.0esr from Debian Testing repos.
• Enable HDR mode in GNOME. No display scaling (font is scaled from tweaks), i.e. display is at 100%.
• Set gfx.wayland.hdr=true from about:config

Actual results:

I see visible flickering on use. (Or a kind of "unstable" viewing experience overall, I lack the vocabulary to exactly describe it)

I'll be attaching 4 files (can't attach right now since form only allows 1 attachment):

• Recording from mobile with gfx.wayland.hdr=false
• Recording from mobile with gfx.wayland.hdr=true
• Screencast using built-in GNOME function with gfx.wayland.hdr=false
• Screencast using built-in GNOME function with gfx.wayland.hdr=true

I took recording from mobile to show what actually I see when I set gfx.wayland.hdr=true. The screencast doesn't show it, though it does show flickering black boxes elsewhere.

The video is of an example page (github.com/python/cpython/issues/58310) where I just use mouse to scroll up and down repeatedly to demonstrate an instance of the issue visibly. Check the top title box element especially.

Expected results:

Smooth rendering / no flickering

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Gtk' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Siddh Raman Pant]

Attachment: Repro videos

Hmm the recordings are past the allowed file size, so I uploaded the videos on Google drive.

Please download them instead of using Google viewer to see, as it reduces the quality.

Comment 3

[Siddh Raman Pant]

I thought link would show up but it didn't. So here's the link: https://drive.google.com/drive/folders/1KgusW6RTRAWE8gn2Vx1VjUo4vn9jFLEN

Comment 4

[Siddh Raman Pant]

Attachment: Youtube example

Here's another example for https://www.youtube.com/watch?v=LxnMg0I0LZM&t=113s with no existing site data. Notice how the flickering happens. I can see the black box flickering this time.

Comment 5

[Siddh Raman Pant]

Attachment: Switching example

Another example where I switch between two tabs. If you notice carefully there is some unnatural flickering which is not content change.

Comment 6

[Martin Stránský [:stransky] (ni? me)]

Please attach your about:support page.
Thanks.

Comment 7

[Siddh Raman Pant]

Attachment: about_support.json

Comment 8

[Martin Stránský [:stransky] (ni? me)]

Thanks, added to HDR tracker.