Infinite contrast with ICC profile without black point data

mpv Information

mpv v0.41.0 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Dec 25 2025 15:27:46
libplacebo version: v7.358.0 (v7.351.0-106-gbc90ef9-dirty)
FFmpeg version: N-122267-gabb152413
FFmpeg library versions:
   libavcodec      62.23.102
   libavdevice     62.2.100
   libavfilter     11.10.101
   libavformat     62.8.101
   libavutil       60.20.100
   libswresample   6.2.100
   libswscale      9.3.100

Other Information

- Windows version: 11 24h2 26100.4061
- GPU model, driver and version: GTX1070, 582.28
- Monitor: Dell h2421hs [SDR]
- Source of mpv: winget
- vo=gpu-next

Reproduction Steps

Enabling ICC profile makes near-black regions noticeably darker than without it.

Tested with Dell factory ICC profile, and with the standard Windows "sRGB IEC61966-2.1" ICC profile.

The default (non-ICC) rendering closely matches madVR configured as:

• This display is already calibrated
• Pure power curve 2.20

The issue is identical with Vulkan and D3D11.

The following options made no visible difference:
--target-trc=gamma2.2
--icc-use-luma=no
--icc-force-contrast=1000

logfile says:
[v][vo/gpu-next/libplacebo] Opened ICC profile:
Raw black point: X=0.000000% Y=0.000000% Z=-0.000000%
Contrast = 203 cd/m^2 : 0.001 mcd/m^2 ≈ 203000000 : 1
Measured primaries:
White: x=0.312696, y=0.329020
Red: x=0.649, y=0.336
Green: x=0.310, y=0.618
Blue: x=0.146, y=0.055
Containing primaries: ITU-R Rec. BT.2020 (Ultra HD)
Transfer function: IEC 61966-2-4 sRGB (CRT emulation)

Even when using:

--icc-force-contrast=1000

the log still reports the same contrast value.

Q: Is the reported black point of zero and the resulting ~203,000,000:1 contrast expected for a normal SDR ICC profile?
P.S. --vo=gpu - no image, just grey screen. --vo=direct3d has no issue (maybe cuz it doesn't load profile?)

Expected Behavior

mpv --no-config

Result:

• correct black level
• visually matches madVR

Actual Behavior

mpv --no-config --icc-profile-auto=yes
or

mpv --no-config --icc-profile="C:\Windows\System32\spool\drivers\color\sRGB Color Space Profile.icm"

Result:

• darker near-blacks / shadow detail
• visible difference from baseline

Log File

output.txt

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

• I tested and confirmed that the issue exists with the latest release version or newer.
• 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.

Start by reproducing the difference between --icc-profile-auto=yes or --icc-profile and the no-config baseline with --vo=gpu-next, using the attached output.txt to inspect the reported black point and contrast. Compare the Vulkan and D3D11 results, then verify that ICC-enabled rendering preserves the expected SDR black level without the reported extreme contrast.