EIA-608 subtitles in TS display unrecognized characters

mpv Information

mpv --version
mpv 0.38.0 Copyright © 2000-2024 mpv/MPlayer/mplayer2 projects
 built on Apr 17 2024 19:18:44
libplacebo version: v7.349.0
FFmpeg version: 7.0.1
FFmpeg library versions:
   libavutil       59.8.100
   libavcodec      61.3.100
   libavformat     61.1.100
   libswscale      8.1.100
   libavfilter     10.1.100
   libswresample   5.1.100

Important Information

• Platform version:
• GPU model, driver and version:
• Source:
• Introduced in version:

Reproduction Steps

Play the ts file and enable subtitles, which are in format EIA-608. They are not displayed.

Expected Behavior

Display subtitles.

Actual Behavior

Not displayed.

Sample Files

600.ts.zip

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 by reproducing the missing EIA-608 subtitles with the attached 600.ts sample while enabling subtitles in mpv. Trace the subtitle handling path for EIA-608 data in MPEG-TS and compare it with formats that display correctly; done means the sample's subtitles are rendered as expected.