Follow up question: What’s the difference between alass itself and the auto-sub-retimer from the site you linked to? Is the latter just a wrapper around alass that tries to make things a little easier to use? And is that the one you use? I had a show I was trying to sync manually last month before I got fed up, so I might test it out on that show this weekend.
I only use the alass script. I dont know this auto sub retimer
I just select the eng subtitle and then in seconds it syncs the japanese subs.
Does it work when the English subtitles are embedded in the MKV file, or you have to extract it first?
embedded
that’s why I said in seconds you can do it. For example, dragon quest 2020 there were like 10 subs in the episode, I just selected eng everytime and the srt is generated already synced with the episode name.
Okay, so I gave alass a try. First I tried it on a show that has no splits, it’s just that every episode was out of sync by a different amount, so fixing them manually was a hassle. I only tried the first two episodes so far (with the --no-split flag set), which worked flawlessly. For episode 1, I had estimated the subtitles as being 500ms ahead, while alass determined it was 460ms. For episode 2, I had estimated the subtitles as being 150ms ahead, while alass determined it was 200ms. I’m always struggling within a +/- 50ms range anyway, so both those results are great.
On the other hand, I tried it with two shows with splits and it didn’t go well at all. For the first, it correctly found the splits, but it was still off by at least half a second, which is too far out of sync for my taste. The second show was a little weird, because it’s unclear to me if it had true splits or if it was stretched or something because different parts of the episode were out of sync by different amounts, but it’s not like there were minute+ long gaps. However, alass tried to make the first lines of subtitles 10 seconds earlier, even though the original was within a second or so of the correct alignment.
All that was just with the default (split) settings though, so maybe there’s more I can tweak. That said, what do you mean by the following?
You said you’re only using the alass script (not the auto sub retimer thing), but I don’t see a way to indicate another sub file (e.g. English subs) to sync to.
the episodes you want to watch, if you watch with english subtitles are they synced perfectly?
if so, when you use the script it just syncs the jp subtitles, that’s all. I dont do anything else, nothing is off nor delayed nor ahead.
As far as can tell, alass just analyzes audio (if given an mkv), not another subtitle file like the English subs… Can you give an example of a command you run to sync a file?
So I just tested the Windows-64 version on a video mkv file where I had replaced the built-in subtitle track without retiming it first and so that was off-timed, and it looks like the default option must just analyze the audio since it correctly retimed a separate subtitle file.
I used option:
alass.bat movie.mkv incorrect_subtitle.ass output.ass
But per the docs, it appears there is an option to take timings from another subtitle file instead, if you have one:
alass.bat reference_subtitle.ssa incorrect_subtitle.srt output.srt
Haven’t tried it, but seems like it would be a good option if you did have a reference file that you knew was correctly timed (like an English one extracted from the video).
Yes, I see that, but @evandcs claims they did this with the subtitles embedded in the mkv file, which is why I’m confused.
when you run the script (run_me.bat) you just choose you want to sync srt subtitles, not audio
then it will display all subtitles embedded, then you type which track you want to be based to sync the external srt jp subtitle,
I just followed the tutorial on the website. Never had any problem.
Okay, so as I suspected you’re not just using the alass script like you previously indicated. You are using the auto sub retimer thing, since that’s what has the run_me.bat. Mystery solved I guess, even if it took two days.
Thanks again. I probably could have asked for clarification more directly to avoid the back and forth.