This tool can be used to permanently sync subtitles with movies if the subtitles are off by a different amount of seconds in multiple parts of the video.
If the subtitles have the same delay the whole video, use the shifter tool instead.
This is an example of when this tool will work: if you have a 20 minute long movie with subtitles, and in the first 10 minutes of the movie the subtitles have a delay of 2 seconds, and the last 10 minutes have a delay of 4 seconds, you can fill in the following values to fix the subtitles:
Entering these values will apply a 2 second shift for the first 10 minutes, and a 4 second shift the last 10 minutes.
This tool will only work if the subtitles get more out of sync at specific points. It will not work if the subtitles gradually get more ouf of sync.
The shifter tool is made to adjusts the whole file at once.