1902984 - Using ambient mode in youtube changes video saturation

Status: UNCONFIRMED

(Core :: Audio/Video: Playback, defect)

Description

[u756002]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:127.0) Gecko/20100101 Firefox/127.0

Steps to reproduce:

I can reproduce it in both new and existing profiles when dark theme is active:

1. Open firefox from taskbar
2. type "youtube.com" in address bar and hit enter
3. open any video when dark theme is enabled
4. click on cog icon in player and toggle ambient mode

Actual results:

Toggling ambient mode on and off changes video saturation. "Ambient mode on": makes video more saturated (and it makes it look the same as in chromium browser) and toggling "ambient mode off" makes it less saturated.

Visually it looks very similar to setting wrong color range on monitor.

Problem is very inconsistent:

1. it sometimes stops after few videos
2. it sometimes stops after changing codec from VP9 to AVC or AV1
3. it also sometimes switch which codec is desaturated (for me it's most often VP9)

Only way for me to reproduce it consistently is to close browser and open it again when not forcing any codec and allowing youtube to choose automatically (it defaults to VP9 on this device).

Wide view (after clicking T on keyboard) and full screen view (F) inherits color of default view and doesn't change when active.

Performance profiler links:
https://share.firefox.dev/3KM7uDy
https://share.firefox.dev/4crqNxX

Expected results:

Video saturation shouldn't change depending on ambient mode (or at least it doesn't in chromium)

Comment 1

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

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit BugBot documentation.

Comment 2

[Jim Mathies [:jimm]]

Hmm, trying to reproduce on Windows 11, I don't see any change flipping it back and forth. Not sure what's going on here.