I am working on a project to do subtitles of different languages for a documentary (chinese/japanese/malay). The English version will be the master version.

I understand that the timing for each line of subtitles depends on the time allocated for each character.

How do we 'lock' the timing for all of the english subtitles lines so that each line can be replaced by the equivalent in a foreign language.

I reckon that if the timing is not fixed, the timing will change for each language due to the different character size per line.

Thanks for your help.