`--demuxer-hysteresis-bytes` option will force caching to be enabled

mpv Information

mpv v0.41.0-1049-g0b7ed670f Copyright © 2000-2026 mpv/MPlayer/mplayer2 projects
 built on Sep 14 2026 05:08:55
libplacebo version: v7.371.0 (v7.360.0-124-g3330a51-dirty)
FFmpeg version: N-126548-g6efe500d2
FFmpeg library versions:
   libavcodec      63.12.100
   libavdevice     63.2.100
   libavfilter     12.4.100
   libavformat     63.6.100
   libavutil       61.7.100
   libswresample   7.3.100
   libswscale      10.2.100

Other Information

- Windows version: Win10 22H2
- GPU model, driver and version:
- Source of mpv: https://github.com/zhongfly/mpv-winbuild
- Latest known working version:
- Issue started after the following happened:

Reproduction Steps

when playing local files, caching is disabled by default, but once a non-zero value is set for the --demuxer-hysteresis-bytes option, caching is automatically enabled, and even if you explicitly disable caching (--cache=no), it won't work.

mpv any.mkv --no-config --pause --cache=no --demuxer-hysteresis-bytes=32MiB --log-file=log.txt

Expected Behavior

caching disabled

Actual Behavior

caching enabled, and it seems that the --demuxer-max-bytes option respects --demuxer-hysteresis-bytes.

Log File

log.txt

Sample Files

No response

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.
• I attached the backtrace in the case of a crash.

Start by tracing how --cache, --demuxer-hysteresis-bytes, and --demuxer-max-bytes are handled when opening a local file. Reproduce the reported command with --no-config and inspect log.txt; done means --cache=no keeps caching disabled even when a non-zero hysteresis value is supplied.