Some online video players give you the option to add or subtract delay e.g. by ±0.5s to subtitles to manually sync them to the video currently playing. However I become functionally dyslexic when it comes to actually figuring out how much delay has to be added. I end up randomly adding or subtracting delay and make it work through trial and error.
Is there some rule of thumb I could follow instead to systematically sync subtitles?
Subtitles are glorified text files, each line has a timestamp, like
This tells the player to display the line from 7 minutes, 34 seconds, 480 milliseconds until 7 minutes, 38 seconds, 80 milliseconds.
If you want the subtitles to be earlier, you’re subtracting from those times so it’s minus, if you want them to be later, you’re adding so it’s plus.