I've used Subshifter website occasionally for years to do that. There are others I guess. Subshifter can do constant difference as well as stretching, where the

I've used Subshifter website occasionally for years to do that. There are others I guess. Subshifter can do constant difference as well as stretching, where the subtitles are at the wrong frame rate. You find and enter in the times where subs should be, at one spot near the beginning and one near the end. It does its job well. It's nice when people share their cool tools free online like this. :-) https://subshifter.bitsnbites.eu/ https://subshifter.bitsnbites.eu/