For display purposes, it's better to show scrambled text - at least
that's a more actionable failure mode than spamming the terminal with
FFmpeg nonsense error messages.
This avoids the obnoxious and pointless
"Invalid UTF-8 in decoded subtitles text; maybe missing -sub_charenc option"
FFmpeg error, which will be spammed on every single subtitle event. We
don't even have a -sub-charenc option, fuck FFmpeg.
Did I mention fuck FFmpeg yet? Because fuck FFmpeg.