Activation of autocrop changes video color

mpv Information

mpv v0.40.0-462-ge6885cb92 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Nov 19 2025 22:47:02
libplacebo version: v7.351.0
FFmpeg version: n8.0
FFmpeg library versions:
   libavcodec      62.11.100
   libavdevice     62.1.100
   libavfilter     11.4.100
   libavformat     62.3.100
   libavutil       60.8.100
   libswresample   6.1.100
   libswscale      9.1.100

Other Information

Operating System: Arch Linux 
KDE Plasma Version: 6.5.3
KDE Frameworks Version: 6.20.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-273-linux-tkg (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor
Memory: 64 GiB of RAM (62.7 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 4080
Product Name: X570M Pro4

mpv from aur mpv-git package

Reproduction Steps

I was testing with the autocrop script. I opened an hdr movie twice and immediately paused and scrubbed to a frame in both and autocropped one. Place both side-by-side so each had half screen. The autocropped one darkened. I assume, but don't know, that hdr disabled on activation.

Manual cropping does not reproduce this.

Expected Behavior

Color/image to remain the same.

Actual Behavior

Color/Image darked

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 with the attached output.txt and reproduce the issue using the autocrop script on an HDR movie, comparing activation with manual cropping. Trace the color or HDR handling triggered by autocrop activation. Done means activating autocrop leaves the video color and image unchanged.