Add or subtract time

[Angelk90]

Hi @zhw2590582 , it happens that some subs are synchronized with other raws, different from what we find.

Would it be possible to add an option to add or remove start and end times to all subtitles present? I don't know if I was able to explain myself well.

https://user-images.githubusercontent.com/20476002/120506417-2fee0100-c3c6-11eb-84ef-4b8029442ecd.mov

[zhw2590582]

I understand what you said. I'll add this function later