HDR color temperature looks different depending on the backend (dmabuf-wayland and gpu-next with waylandvk)

mpv Information

mpv v0.39.0-987-g415b70dc7 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Mar  7 2025 22:45:02
libplacebo version: v7.349.0
FFmpeg version: n7.1
FFmpeg library versions:
   libavcodec      61.19.100
   libavdevice     61.3.100
   libavfilter     10.4.100
   libavformat     61.7.100
   libavutil       59.39.100
   libswresample   5.3.100
   libswscale      8.3.100

Other Information

- Linux version: Arch Linux
- Kernel Version: Linux arch 6.14.0-rc1 #1-Alpine SMP PREEMPT_DYNAMIC Wed, 05 Feb 2025 02:44:22 +0000 x86_64 GNU/Linux
- GPU Model: 01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] [1002:67df] (rev e7)
- Mesa/GPU Driver Version: Mesa 25.0.1-arch1.1
- Window Manager and Version: GNOME Wayland 48.rc
- Source of mpv: AUR
- Latest known working version: None

Reproduction Steps

ENABLE_HDR_WSI=1 mpv --no-config --target-colorspace-hint --vo=gpu-next <HDR Video>

and

mpv --no-config --target-colorspace-hint --vo=dmabuf-wayland <HDR Video>

Expected Behavior

Accurate color reproduction regardless of backend (I don't know which of the two is correct)

Actual Behavior

Different color temperature depending on used backend

Log File

output-dmabuf.txt

output-gpu-next.txt

Sample Files

https://www.youtube.com/watch?v=8a6TnOGyKBw

I carefully read all instruction and confirm that I did the following:

• I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Start with the two reproduction commands using the same HDR video, then compare output-dmabuf.txt and output-gpu-next.txt alongside the attached screenshots. Trace the dmabuf-wayland and gpu-next paths involved in --target-colorspace-hint and determine which backend's color handling is inconsistent; done means HDR color temperature is accurate and consistent between both backends.