Yeah, mkv can handle VOBSUB. I just prefer text based like srt or ass since you can edit the subtitles to get better timings or changing font/ colour or fix spellings really easily. I also find the VOBSUB a bit blurry around the edges of the text.

If you’re happy with the VOBSUB, then the last bit of code above will merge them with the mkv file and they should be automatically on when using vlc.

Thanks for the links, I was thinking about how outdated vobsub2srt was and definitely want to try these instead!

EDIT: https://github.com/gwen-lg/subtile-ocr is better than https://github.com/ruediger/VobSub2SRT Subtitle-ocr had no issue with recognising “I” as “I” while vobsub2srt constantly sees “I” as “|” and blacklisting “|” causes “I” to be recognised as “]” and blacklisting “|” “[” and “]” just leaves a blank space so thanks for the recommendation! I’ll be using that to convert VOBSUB to srt instead

for f in ./*.idx; do
    subtile-ocr -l ger -o "${f%.*}.srt" "$f"; done

And then https://mkvtoolnix.download/ to remove any unwanted subtitles from the mkv files

for f in ./*.mkv; do
    outdir="nosubs"
    mkvmerge -o "${outdir}/$f" --no-subtitles "$f"; done

Finally, I merge the srt files with the mkv files

for f in ./nosubs/*.mkv; do
    outdir=addedsubs
    g="${f##*/}"
    mkvmerge -o "${outdir}/$g" "$f" --language 0:ger --track-name 0:German "${g%.*}".srt; done

Once the files in the addedsubs directory look good, I delete all of the other files. You can add it all to a bash file or make an alias or both and run it wherever