Aegisub

Originally created as a tool to make typesetting, particularly in anime fansubs, a less painful experience, Aegisub has grown into a fully fledged, highly customizable subtitle editor.

It features a lot of convenient tools to help you with timing, typesetting, editing and translating subtitles, as well as a powerful scripting environment called Automation (originally mostly intended for creating karaoke effects, Automation can now be used much else, including creating macros and various other convenient tools).

This is an unofficial snap, the developers may not be responsible for any bugs in it. For any bug reports: https://github.com/vcprocles/aegisub-procles-snap

NOTE: Default program install does not have any Automation functionality. To initialize scripting and install DependencyControl, you should run aegisub-procles.setup-automation. This supported only on candidate, beta and edge channels for now. If you find any issues, be sure to report them to the package maintainer.