8 ms·

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 mar

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/kernel-open/nvidia-drm/nvidia-drm-format.c 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.

fruitworks 9mo ago
nvidia
- jetbalsa 9mo ago
  Right, it IS nvidia's fault at this point, but its still like what? 90% of the consumer GPU market.
  - bitanarch 9mo ago
    They're also selling $3000 nVidia AI workstations that exclusively uses Linux. But what if you want to watch an HDR video on it? No. What if you want to use Google Meet on Chrome/Wayland? It's broken.
  - HansHamster 9mo ago
    Funny how it went from "just get an Nvidia card for Linux" and "oh my god, what did I do to deserve fglrx?" to "just get an AMD card" and "it's Nvidia, what did you expect?"
  - hollandheese 9mo ago
    For aftermarket purchase sure, but 95% of consumer machines are using either Intel or AMD integrated graphics.
- yunnpp 9mo ago
  The way it's not meant to be played.
EnPissant 9mo ago
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 9mo ago
  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 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.
  - EnPissant 9mo ago
    It's not obvious how to interpret the output. I pasted it into chatgpt and it thinks I am using "Format: ABGR2101010" for both monitors (only 1 has HDR on) so I don't trust it. EDIT: See my sibling comment.
    - bitanarch 9mo ago
      Under the Planes section, look for planes that have non-zero "CRTC_ID". Those are the planes that actually get output to your monitor. Here's what I'm getting on an RTX 4090 / InnoCN 27M2V and Cooler Master Tempest GP27U. https://imgur.com/a/SCyyZWt https://imgur.com/a/SCyyZWt
  - EnPissant 9mo ago
    I asked claude to investigate: Your Display Configuration Both monitors are outputting 10-bit color using the ABGR2101010 pixel format. | Monitor | Connector | Format | Color Depth | HDR | Colorspace | |------------------------|-----------|-------------|-------------|--------------|------------| | Dell U2725QE (XXXXXXX) | HDMI-A-1 | ABGR2101010 | 10-bit | Enabled (PQ) | BT2020_RGB | | Dell U2725QE (XXXXXXX) | HDMI-A-2 | ABGR2101010 | 10-bit | Disabled | Default | * Changed the serial numbers to XXXXXXX I am on Wayland and outputting via HDMI 2.1 if that helps. EDIT: Claude explained how it determined this with drm_info, and manually verified it: > Planes 0 and 3 are the primary planes (type=1) for CRTCs 62 and 81 respectively - these are what actually display your desktop content. The Format: field shows the pixel format of the currently attached framebuffer. EDIT: Also note that I am slowbanned on this site, so may not be able to respond for a bit. EDIT: You should try connecting with HDMI 2.1 (you will need a 8k HDMI cable or it will fall back to older standards instead of FRL). EDIT: HDR on youtube appears to work for me. Youtube correctly indentifies HDR on only 1 of my monitors and I can see a big difference in the flames between them on this scene: https://www.youtube.com/watch?v=WjJWvAhNq34 https://www.youtube.com/watch?v=WjJWvAhNq34
3A2D50 9mo ago
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 9mo ago
  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 9mo ago
    I'll look into that tomorrow. See my other comment for Linux vs Blu-ray.
  - 3A2D50 9mo ago
    I connected two portable LCDs I have that support HDR. Both LCDs didn't automatically detect HDR and looked washed out initially. I had to manually change them to HDR. The signal according to the AVR was... Resolution: 4K60 HDR: HDR10 Color Space: YCbCr 4:4:4/BT.2020 Pixel Depth: 12bits FRL Rate: --- ...for both the LCDs. Here are their specs: https://www.amazon.com/dp/B09Q5L245X https://www.amazon.com/dp/B08131MVGT With the HDR off for both the desktop and LCD, the Youtube HDR video at 19s seems flat. I could increase the monitor's brightness to match the planet brightness when HDR is on, but space would be washed out. Of course without HDR, lowering the brightness for darker space results in the planet becoming darker too. When HDR is off for LCD and desktop I do still see a difference between Youtube's HDR and SDR videos. For example, at the 19s mark I cannot see most of the debris scattering between the viewer and the planet in the SDR video. That should be the case for you too. *Edit: Strange... one of the monitors states 10bit colors in the link even though the AVR claimed a signal of 12bits. Not sure what to make of that!
jact 9mo ago
I find that running HDR games in standalone steam gamescope works great for my OLED tv. Not perfect, but great.

fruitworks 9mo ago

nvidia

jetbalsa 9mo ago
Right, it IS nvidia's fault at this point, but its still like what? 90% of the consumer GPU market.
- bitanarch 9mo ago
  They're also selling $3000 nVidia AI workstations that exclusively uses Linux. But what if you want to watch an HDR video on it? No. What if you want to use Google Meet on Chrome/Wayland? It's broken.
- HansHamster 9mo ago
  Funny how it went from "just get an Nvidia card for Linux" and "oh my god, what did I do to deserve fglrx?" to "just get an AMD card" and "it's Nvidia, what did you expect?"
- hollandheese 9mo ago
  For aftermarket purchase sure, but 95% of consumer machines are using either Intel or AMD integrated graphics.
yunnpp 9mo ago
The way it's not meant to be played.

EnPissant 9mo ago

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 9mo ago
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 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.
- EnPissant 9mo ago
  It's not obvious how to interpret the output. I pasted it into chatgpt and it thinks I am using "Format: ABGR2101010" for both monitors (only 1 has HDR on) so I don't trust it. EDIT: See my sibling comment.
  - bitanarch 9mo ago
    Under the Planes section, look for planes that have non-zero "CRTC_ID". Those are the planes that actually get output to your monitor. Here's what I'm getting on an RTX 4090 / InnoCN 27M2V and Cooler Master Tempest GP27U. https://imgur.com/a/SCyyZWt https://imgur.com/a/SCyyZWt
- EnPissant 9mo ago
  I asked claude to investigate: Your Display Configuration Both monitors are outputting 10-bit color using the ABGR2101010 pixel format. | Monitor | Connector | Format | Color Depth | HDR | Colorspace | |------------------------|-----------|-------------|-------------|--------------|------------| | Dell U2725QE (XXXXXXX) | HDMI-A-1 | ABGR2101010 | 10-bit | Enabled (PQ) | BT2020_RGB | | Dell U2725QE (XXXXXXX) | HDMI-A-2 | ABGR2101010 | 10-bit | Disabled | Default | * Changed the serial numbers to XXXXXXX I am on Wayland and outputting via HDMI 2.1 if that helps. EDIT: Claude explained how it determined this with drm_info, and manually verified it: > Planes 0 and 3 are the primary planes (type=1) for CRTCs 62 and 81 respectively - these are what actually display your desktop content. The Format: field shows the pixel format of the currently attached framebuffer. EDIT: Also note that I am slowbanned on this site, so may not be able to respond for a bit. EDIT: You should try connecting with HDMI 2.1 (you will need a 8k HDMI cable or it will fall back to older standards instead of FRL). EDIT: HDR on youtube appears to work for me. Youtube correctly indentifies HDR on only 1 of my monitors and I can see a big difference in the flames between them on this scene: https://www.youtube.com/watch?v=WjJWvAhNq34 https://www.youtube.com/watch?v=WjJWvAhNq34

3A2D50 9mo ago

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 9mo ago
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 9mo ago
  I'll look into that tomorrow. See my other comment for Linux vs Blu-ray.
- 3A2D50 9mo ago
  I connected two portable LCDs I have that support HDR. Both LCDs didn't automatically detect HDR and looked washed out initially. I had to manually change them to HDR. The signal according to the AVR was... Resolution: 4K60 HDR: HDR10 Color Space: YCbCr 4:4:4/BT.2020 Pixel Depth: 12bits FRL Rate: --- ...for both the LCDs. Here are their specs: https://www.amazon.com/dp/B09Q5L245X https://www.amazon.com/dp/B08131MVGT With the HDR off for both the desktop and LCD, the Youtube HDR video at 19s seems flat. I could increase the monitor's brightness to match the planet brightness when HDR is on, but space would be washed out. Of course without HDR, lowering the brightness for darker space results in the planet becoming darker too. When HDR is off for LCD and desktop I do still see a difference between Youtube's HDR and SDR videos. For example, at the 19s mark I cannot see most of the debris scattering between the viewer and the planet in the SDR video. That should be the case for you too. *Edit: Strange... one of the monitors states 10bit colors in the link even though the AVR claimed a signal of 12bits. Not sure what to make of that!

jact 9mo ago

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