[bitanarch]

HDR still doesn't really work on Linux w/ nVidia GPUs.

1. 10bpp color depth is not supported on RGB monitors, which are the majority of LCD displays on the market. Concretely, ARGB2101010 and XRGB2101010 modes are not supported by current nVidia Linux drivers - the drivers only offer ABGR2101010 and XBGR2101010 (See: https://github.com/NVIDIA/open-gpu-kernel-modules/blob/main/...).

2. Common browsers like Chrome and Firefox has no real support for HDR video playback on nVidia Linux drivers. The "HDR" option appears on YouTube, but no HDR color can be displayed with an nVidia GPU.

Also, video backgrounds in Google Meet on Chrome are broken with nVidia GPUs and Wayland. Ironically it works on Firefox. This has been broken for a few years and no fix is in sight.

The "HDR" toggle you get on Plasma or Mutter is hiding a ton of problems behind the scenes. If you only have 8bpp, even if you can find an app that somehow displays HDR colors on nVidia/Wayland - you'll see artifacts on color gradients.

[3A2D50]

I have Interstellar on 4K UltraHD Blu-ray that features HDR on the cover, Sony 4K Blu-ray player (UBP-X700) and a LG G4 OLED television. I also have an AVR (Denon AVR-S760H 7.2 Ch) connecting both the Blu-ray and a PC running Linux with a RTX 3060 12GB graphic card to the television. I've been meaning to compare HDR on Linux with the Blu-ray. I guess now better than never. I'll reply back to my post after I am done.

[bitanarch]

Try it with different monitors you have. The current nVidia Linux drivers only has BGR output for 10bpp, which works on TVs and OLEDs but not most LCDs monitors.

My monitors (InnoCN 27M2V and Cooler Master GP27U) require RGB input, which means it's limited to 8bpp even with HDR enabled on Wayland. There's another commentator below who uses a Dell monitor and manages to get BGR input working and full HDR in nVidia/Linux.

[3A2D50]

Television HDR mode is set to FILMMAKER, OLED brightness 100%, Energy Saving Mode is off. Connected to AVR with HDMI cable that says 8K.

  PC has Manjaro Linux with RTX 3060 12GB

  Graphic card driver: Nvidia 580.119.02

  KDE Plasma Version 6.5.4

  KDE Frameworks Version: 6.21.0

  Qt Version: 6.10.1

  Kernel Version 6.12.63-1-MANJARO

  Graphics Platform: Wayland

Display Configuration

  High Dynamic Range: Enable HDR is checked

  There is a button for brightness calibration that I used for adjustment.

  Color accuracy: Prefer color accuracy

  sRGB color intensity: This seems to do nothing (even after apply). I've set it to 0%.
  Brightness: 100%

TV is reporting HDR signal.

AVR is reporting...

  Resolution: 4KA VRR

  HDR: HDR10

  Color Space RGB /BT.2020

  Pixel Depth: 10bits

  FRL Rate 24Gbps

I compared Interstellar 19s into Youtube video in three different ways on Linux and 2:07:26 on Blu-ray.

For Firefox 146.0.1 by default there is no HDR option on Youtube. 4K video clearly doesn't have HDR. I enabled HDR in firefox by going to about:config and setting the following to true: gfx.wayland.hdr, gfx.wayland.hdr.force-enabled, gfx.webrender.compositor.force-enabled. Color look completely washed out.

For Chromium 143.0.7499.169 HDR enabled by default. This looks like HDR.

I downloaded the HDR video from Youtube and played it using MPV v0.40.0-dirty with settings --vo=gpu-next --gpu-api=vulkan --gpu-context=waylandvk. Without these settings the video seems a little too bright like the Chromium playback. This was the best playback of the three on Linux.

On the Blu-ray the HDR is Dolby Vision according to both the TV and the AVR. The AVR is reporting...

  Resolution: 4k24

  HDR: Dolby Vision

  Color Space: RGB

  Pixel Depth 8bits

  FRL Rate: no info

...I looked into this and apparently Dolby Vision uses RGB tunneling for its high-bit-depth (12-bit) YCbCr 4:2:2 data. The Blu-ray looks like it has the same brightness range but the color of the explosion (2:07:26) seems richer compared to the best playback on Linux (19s).

I would say the colors over all look better on the Blu-ray.

I might be able to calibrate it better if the sRGB color setting worked in the display configuration. Also I think my brightness setting is too high compared to the Blu-ray. I'll play around with it more once the sRGB color setting is fixed.

*Edit: Sorry Hacker News has completely changed the format of my text.

[jact]

I find that running HDR games in standalone steam gamescope works great for my OLED tv. Not perfect, but great.

[EnPissant]

I don't think this is true. I can go into my display settings in kde plasma and enable HDR and configure the brightness. I have a nvidia blackwell card.

[bitanarch]

You can enable, yes. But (assuming you're on an LCD display and not an OLED), you're likely still on XRGB8888 - i.e. 8-bit per channel. Check `drm_info`.

Also, go to YouTube and play this video: https://www.youtube.com/watch?v=onVhbeY7nLM

Do it once on "HDR" on Linux, and then on Windows. The "HDR" in nVidia/Linux is fake.

The brightness you see on Plasma or Mutter is indeed related to the HDR support in the driver. But - it's not really useful for the most common HDR tasks at the moment.

[fruitworks]

nvidia

[jetbalsa]

Right, it IS nvidia's fault at this point, but its still like what? 90% of the consumer GPU market.

[yunnpp]

The way it's not meant to be played.