How do I get --sub-filter-sdh-harder=yes to work?

[mathiaslovnes]

Hey.

I'm looking to remove SDH such as "(Mark) ..." or "(A rustle in the wind)"

Looking at the mpv manual, it seems like "--sub-filter-sdh-harder=<yes|no>" should do the trick, but I can't get it to work. It doesn't filter anything. Does this only work for .ass subs? Because I am using .srt subs

So, does anyone know how I can filter SDH out of .srt subtitles?