Subtitle Edit time gap between lines

[GregT46]

I use Subtitle Edit and save subtitles as Advanced Sub Station Alpha(.ass). I save a subtitle with a minimum 83 millisecond gap between lines. The next time I open it the gap goes to 80 millisecond. Just to be sure I change to 83ms gap again and save but when opening it still reverts to 80ms. Has anybody seen this happen with their Advanced Sub Station Alpha subtitles. One more thing is if I save the file SubRip(.srt) the gaps are maintained when reopening the file. Anyone else have this happen when working with Subtitle Edit? Any info with this would be appreciated.

[jagabo]

PAL frame rate? At 25 fps each frame is displayed for 40 ms. So everything works in 40 ms increments.

[GregT46]

Mine is NTSC frame rate. Video fps 23.976. Subtitle Edit shows 2 frame gap equal 83 ms. I have gap set for 83 ms save but when reopened gap reverts to 80 ms Thanks for reply. Would appreciate any more info you have. GregT

[Ennio]

Same behaviour here. Gaps initially set to minimum 42ms, they are changed to 40ms when reopen the ASS.
I am doubting whether this is a bug or proper behaviour for ASS format.

[jagabo]

I saw this:

https://www.md-subs.com/blog/line-spacing-in-ssa

A note of caution

The ASS format has a whole host of problems, which is why it’s not standardized in the industry. Most importantly, its timing format uses centiseconds rather than frames or milliseconds, so when you import from or export to ASS, the round-off errors will sometimes push your timecodes over to the adjacent frame, spoiling your minimum intervals, shot change gaps, durations, etc. This can be avoided if you work around it carefully, but, unless you know exactly what you’re doing, it’s better to use something else for certain projects.

So the timing within ASS is always in hundredths of a second, ie, two decimal places. So 83 milliseconds (0.083) becomes 80, milliseconds (0.08). 42 milliseconds (0.042) becomes 40 milliseconds (0.04).

[GregT46]

Thanks for the explanation. I did not know ass/ssa files deal in centiseconds. This makes sense to me. I thought I was doing something wrong. Maybe in the future ass/ssa files can be formatted to work with milliseconds. Again thanks for the info. GregT

[jagabo]

Maybe in the future ass/ssa files can be formatted to work with milliseconds.

If you look at the basic format of subtitle lines in SSA files (a line stolen from a random SSA file);

 
Dialogue: 0,0:00:17.95,0:00:20.79,Credits ENG,,0,0,0,,{\blur0.6\c&HF9EBEE&\fscx61.017\fscy76\pos(100.607,70.222)}Planning

You'll see that there are only two decimal places. If you extended that to three decimal places (or a variable number up to the following comma) many renderer's parsers will probably have to be modified as well as the editors. I doubt this will happen any time soon.