aegisub - 3.2.2+dfsg-7.2 main

Originally created as 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).