[schumi2004]

I'm not sure if this has been asked before but would it be possible to have the subtitle offset steps configurable like it's done for video skip steps?

Now i have a workaround described here but it would be better if this was build-in.

http://forum.kodi.tv/showthread.php?tid=251621

[FernetMenta]

Subtitles have timestamps and are supposed to be displayed with matching video timestamp. Why do you think this should be configurable? Do you observe sync issues. What platform do you use, what source of video?

[schumi2004]

I'm requesting this because with external subs (and only with using external subs) you often can have out of sync subtitles.
My experience is that in 9 out of 10 it can be solved by setting the offset to 1 sec or more. Mostly when i need to manual sync is that it goes out of sync during a commercial brake cut and this can be solved every time with a second. Having steps from 0.1 seconds is fine if it's only minimal out of sync but that's hardly the case, the need to use 0.1 steps is practically never used in all the situations in ran in to..

I'm running LibreELEC on RPi2's and AMD system, also using Windows and media is mostly 720p mkv's

[FernetMenta]

I'm requesting this because with external subs (and only with using external subs) you often can have out of sync subtitles.

This is an important piece of information. In this case the configured offset should be volatile because it is unlikely that the next video needs the same offset.

[schumi2004]

I'm requesting this because with external subs (and only with using external subs) you often can have out of sync subtitles.

This is an important piece of information. In this case the configured offset should be volatile because it is unlikely that the next video needs the same offset.

Most likely not but if i'm correct the offset configured for current watching media isn't transferred to the next media played.
The media playing next starts from scratch again regarding the subtitle offset.

I would only like to see a configurable menu item that defines the step size in seconds.
Default is 0.1 and i would configure it 1.0, someone else would set it to 0.5 seconds.
So that every click done to sync subs is in configured step size.

Note: English isn't my native language so grammatically i suck

[intimi]

On about 50% of the movies, there is not just a fixed time offset, there is also a difference in speed: subtitled limb behind or just gallup away.
Assuming this has to do with the speed of the movie, I posted the following suggestion. Up to the Kodi wizards to judge about this. It isn't that complicated and to my humble opinion an easy way for users to calibrate subtitle rates.



Consider changing the "subtitles offset" tool after the "sound" button.

It lets you slide forward or backward for max 1 minute to set an offset. This is OK for subtitles at the same speed of the movie.

To grasp it mathematically, this means:

t = timestamp of the subtitle in e.g. the .SRT file
o = offset of the subtitle
t' = t+o or the time the subtitle is actually shown

Actually, if the movie is played at a different rate, there is something like a speed factor. Let's call it "s".

s = speed factor
so a new expression for t' is now:

t' = s*t + o

At a constant speed difference, the subtitles should remain in sync.

However, getting a grip on that speed factor could be tedious, but it is a quite simple problem to solve mathematically, and with the help of an enhanced "subtitle offset" tool. How?

Simply let's calibrate on two places in the movie:
- calibrate for an offset one time and store
- cue the movie for some 15 minutes, calibrate another offset and store

Now it's up to the tool to do some calculations

We have:
t'1 = t1 + o1
t'2 = t2 + o2

offset evolves linearly with play time:

(o - o1) = (t - t1) / (t2 - t1)
o = o1 + (o2 - o1) * (t - t1) / (t2 - t1)

t' = t + o1 + (o2 - o1) * (t - t1) / (t2 - t1)
= (1 + (o2 - o1) / (t2 - t1) )* t +o1 - (o2 - o1) / (t2 - t1) * t1

so the constants "s" and "o" in our equation "t' = s*t + o" are:

s = 1 + (o2 - o1) / (t2 - t1)
o = o1 - (o2 - o1) / (t2 - t1) * t1

Quite a simple solution for a very annoying problem, I thought.