Out of sync VF subtitles.

[accord]

I've tried to make a VF DCP but the subtitles keep getting out of sync! I've already tried to adjust the subtitles frame rate to 24fps (the same as the original DCP) and while it syncs OK in the start it gets out of sync fairly early. I don't know what to do! Any thoughts?

[IoannisSyrogiannis]

If the sync deteriorates gradually, that means that the subtitles are not made for 24 frames. If the original framerate was behaving the same, your problem is still framerate.
If the subtitles are getting earlier and earlier, their original subtitles' framerate is higher and vice versa.

I would export the DCP video to a small MP4 file and check the subtitles with a subtitle editor.

[carl]

If you know what frame rate your original subtitle file was prepared for you can import it into DCP-o-matic, right-click and choose "Advanced settings..." then enter that frame rate in the "Video frame rate that the content was prepared for" box. Then the sync should be calculated correctly.

[accord]

I tried that but it sadly didn't work very well. I tried to adjust the subtitles framerate both through Aegisub and this option on DCP-o-Matic, but it didn't quite work.
Both the movie and the subtitles were in 23.98 FPS and they worked very well and in sync. But when I made the DCP and tried to convert the subtitles frame rate to 24 FPS I had this sync problem.
In the end I burned the subtitles on the file 'cause I was out of time, but I still wanted to know for future reference.
I will try again soon to see if it works and if maybe I was doing something wrong, and then I'll update/ask more questions.
Thanks for the answers!

[carl]

If the video and subs were prepared for the same rate it should have worked without any intervention... do get in touch if you have problems again and we can try to investigate.