Sorry for the dumb question, but what exactly does this do?
`subsync reference.srt -i unsynchronized.srt -o synchronized.srt`
I mean, I already have a synchronized srt file, so what would I be syncing here?
`subsync reference.srt -i unsynchronized.srt -o synchronized.srt`
I mean, I already have a synchronized srt file, so what would I be syncing here?
EDIT: Oh, I should also mention that you don't need a reference.srt -- it can look at the video directly and use that as a reference.
It reads:
====
Although it can usually work if all you have is the video file, it will be faster (and potentially more accurate) if you have a correctly synchronized "reference" srt file, in which case you can do the following:
subsync reference.srt -i unsynchronized.srt -o synchronized.srt
====
I believe you should explain that if you have a reference file in another language which is correctly synchronized with that video, you can use that file instead of the video, as its timestamps will serve as references when synchronizing the target .srt file.
Now this has raised a question, what if the reference file has a different block count? For example, in some languages (like Chinese or Japanese) we can say a lot with fewer characters than in English. So in Chinese a text will stay on the screen for a long time, whereas in English the corresponding text would be split into two or more blocks. Wouldn't that make synchronization less accurate?
BTW that's a cool project. Thanks for sharing!
I just want to thank you for including this use-case, because it's exactly the thing I'm regularly running into. Subs in one language are bundled with the vid, all subs from OpenSubtitles are desynchronized.
If you've already synchronized one of these from the video itself (by using the voice detection algorithm described in the Readme, or maybe even by hand), it looks like you can then synchronize the rest using the already synchronized subtitle file. It's probably faster.
• Open audio/video file with —supposedly— synchronized file
• After a few seconds, I realize the subtitles appear before/after the dialogues
• I immediately close the multimedia player, and open the Terminal
• I execute the “subsync” command which does who knows what
• Open the SRT and discover that the subtitles are now in the correct timestamps
• ???
• Profit
Now: subsync
Soon: Players run subsync internally the press of one button or commandline switch.
The voice audio detection and then mapping is such a neat solution. I would have embedded parts of the surrounding audio in some base64 format into the subtitle file and then used that as an alignment clue. But this won't work when the languages don't match.
I hoped that this solution would sync parts that have really different offsets between the audio and the subs, including changes from negative to positive offsets. Because that's the cases where automatic fixes in e.g. Aegisub don't suffice.
This happens when the vid and the subs are from different releases which apparently were edited for some reason―regional releases or something. Like, after some point the subs are suddenly off by a minute.
E.g. if one subtitle is made for 24 frames per second speed (classic film speed) and you have a video presented in 25 frames per second (common in Europe). The original two hours video in 24 fps is then 5 minutes shorter in the Europe-origin version. Or the opposite: the subtitles for 120 minutes would at the end appear 5 minutes before!
Apparently there are some other speed changes, for which I don't know how they happen.
I have done one such correction once, using the linear function to model the correction ^based on the target times of the first and of the last title.