2012285 - HDR video support on Linux works, but looks washed out.

Status: UNCONFIRMED

(Firefox :: General, defect)

Description

[Thibault [:thibaulltt]]

Attachment: firefox-hdr-not-working.png

Hi, I seem to not be able to get HDR content playing on most YouTube test videos, but I'm unsure at which part of the Linux > Nvidia > KDE > Firefox is causing the issue! It doesn't seem to be on the Firefox side, as both Browser Console and regular Console do not seem to be showing any errors, but I want to make sure of it.

I'm currently testing this using Fedora 42 (KDE edition) and I have enabled both the gfx.wayland.hdr and gfx.wayland.hdr.force-enabled variables (only the former at first, then both) on both Firefox 147.0.1 and Zen 1.17.15b (based on Firefox 146.0.1, which I'm using to write this). I run an Nvidia card, with the proprietary drivers installed directly from Nvidia, as I need their CUDA runtime as well. In KDE's System Settings, HDR is enabled and my monitor is detecting a 10-bit HDR signal coming in. For reference, my monitor is a MSI 321UPX QD-OLED. HDR viewing is working on Windows (same machine, I have a dual-boot installed).

I tried to watch the following video, as I had seen it a lot while browsing for a new TV a while back and know what it's supposed to look like: https://www.youtube.com/watch?v=njX2bu-_Vw4
I have attached a screenshot from the YouTube page in question: in the thumbnail on the bottom, you see a rough approximation of what this scene is supposed to look like (thumbnails are served as SDR images from YouTube directly) and on the top you see what it's currently displayed as.

The video decodes perfectly fine, but the colors seem really washed out, as if they were displayed in log format, before applying any LUT or color matrix transformation: I seem to stumble upon the same issue as Marco a few comments above. Based on M. Stransky's post I stumbled upon, I checked what hardware and Wayland extensions I had access to on this PC. From the available Vulkan extensions, I seem to only have VP9 decoding v1 available in-hardware. My KWin compositor has access to the wp_color_manager_v1 protocol.

I'm open to forwarding more information your way, should you need to.

Comment 1

[Thibault [:thibaulltt]]

Oops, as this was originally written as a response to bug 1642854, the comments I refer to in the original post are those two comments: (first, second).