screenshot function doesn't add an ICC profile to hdr pngs, causing the image to be washed out when uploaded to discord

mpv Information

mpv v0.40.0 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
libplacebo version: v7.349.0
FFmpeg version: 7.1.1 (runtime 7.1.2)
FFmpeg library versions:
   libavcodec      61.19.101
   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: Fedora Linux 42 (KDE Plasma Desktop Edition)
- Kernel Version: Linux 6.16.12-200.fc42.x86_64
- GPU Model: AMD Radeon RX 7900 XTX
- Mesa/GPU Driver Version: Mesa 25.1.9
- Window Manager and Version: Kwin 6.4.5-1.fc42
- Source of mpv: fedora repo
- Latest known working version: N/A
- Issue started after the following happened: N/A

Reproduction Steps

steps to reproduce (this requires a config / launch arguments to reproduce the issue)

1. add vo=gpu-next target-colorspace-hint=yes gpu-api=vulkan gpu-context=waylandvk screenshot-format=png screenshot-tag-colorspace=yes screenshot-high-bit-depth=yes to your config
2. launch mpv and drop / paste a hdr file or url, then take a screenshot using the screenshot function (s)
3. locate the screenshot, open a terminal and type in magick identify -verbose [filename]

Expected Behavior

Profiles: Profile-icc:, icc:copyright, icc:description and png:iCCP: chunk was found should be present in the saved png, and the image should retain HDR when uploading to discord.

Actual Behavior

these characteristics are not present in the HDR png, this causes the image to become washed out lose its HDR when uploading to discord.

comparison between mpv hdr png and reshade hdr png:
(left is mpv, right is reshade)

what the image looks like in discord:

Log File

output.txt

Sample Files

No response

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 at mpv's screenshot function with the listed HDR configuration, then use magick identify -verbose on the generated PNG to inspect its color metadata. Done means HDR screenshots contain an ICC profile and the expected png:iCCP markers, retaining HDR appearance when uploaded to Discord.