Timing discrepancy with bd:// playback after seeking

mpv Information

mpv v0.39.0-615-gca211b5b Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Jan 11 2025 00:10:20
libplacebo version: v7.350.0 (v7.349.0-30-g056b852-dirty)
FFmpeg version: N-118281-gb76053d8b
FFmpeg library versions:
   libavcodec      61.31.100
   libavdevice     61.4.100
   libavfilter     10.6.101
   libavformat     61.9.105
   libavutil       59.55.100
   libswresample   5.4.100
   libswscale      8.13.100

Other Information

- Windows version: Microsoft Windows NT 10.0.26100.0/26100.1457
- GPU model, driver and version: NVIDIA GeForce RTX 3080, DCH, 560.94
- Source of mpv: https://github.com/shinchiro/mpv-winbuild-cmake/releases/tag/20250111
- Latest known working version: N/A (earliest tested was v0.30.0)
- Issue started after the following happened: N/A

Reproduction Steps

I'm trying to play some Blu-ray discs with external subtitles. Works as expected when played from start to finish, but seeking ahead appears to shift the timing, resulting in the subtitles playing too quickly.

(BAD) open from disc, seek ahead to ending credits

# log: output-bd-seek-cli-bad.txt
mpv bd://12/E:/ --no-config --start=00:09:45.00 --sub-file=[...]

(OK) open from disc, play to completion without seeking

# log: output-bd-no-seek-ok.txt
mpv bd://12/E:/ --no-config --sub-file=[...]

(OK) open from local .m2ts file, seek ahead to the same time

# log: output-m2ts-seek-ok.txt
mpv 00070.m2ts --no-config --start=00:09:45.00 --sub-file=[...]

Expected Behavior

After seeking ahead, playing for a few seconds, then pausing on a specific frame, the current time in the OSD should match up across all instances and the subtitles should remain in sync.

Actual Behavior

When playing from disc with the bd:// URL, the time has now drifted ahead (00:09:49.333 vs. 00:09:48.505) and the subtitles are playing too early. This happens regardless of whether the seek was done with --start= or manually from the OSD.

However, if the video was played from disc up to this point without seeking ahead, the time will match the local .m2ts file and the subtitles will remain in sync as expected.

output-bd-seek-cli-bad.txt	output-bd-no-seek-ok.txt	output-m2ts-seek-ok.txt

Log File

• output-bd-seek-cli-bad.txt
• output-bd-seek-manual-bad.txt
• output-m2ts-seek-ok.txt
• output-bd-no-seek-ok.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.

Reproduce the discrepancy with the bd:// commands and compare output-bd-seek-cli-bad.txt and output-bd-no-seek-ok.txt against output-m2ts-seek-ok.txt. Trace the bd:// playback and seeking path first; done means seeking no longer advances the OSD timestamp or causes external subtitles to play early, matching local m2ts and uninterrupted disc playback.