Why do subtitles go out-of-synch??

[GregK]

For months now, I've been using AVI Recomp to hardcode subtitles (.srt format) onto avi files before putting them into DMF6, but any time I've tried simply using the srt file directly in DMF, my resulting DVD ends up with the subtitles going further and further out-of-synch with the movie until they're almost 20 seconds off! Yes, I use Subtitle Workshop to make sure the srt subtitle files are correctly set up with whatever avi I have, but it's never worked right, no matter what I do.

Any ideas as to why DMF6 doesn't do the subtitles correctly?

[sjj1805]

Interesting observation.
If you open a srt file with Windows notepad you will see it is a text file with time codes, text positioning information and the like.

What is more likely is that the length of the video is different rather than the subtitle file. As an experiment compare the duration of the avi file that has the subtitles in synch, with the duration of the completed DVD where the subtitles are now out of synch.

If my suspicions are correct you could alter the timing information in the srt file.

[GregK]

No, SJJ, you don't understand....whatever movie I'm dealing with (these are always foreign films with English subtitles in srt format), I can watch the AVI file by itself in whatever media player I choose and the subtitles are always synched properly, and either way....even before doing anything with it in either AVI Recomp (to hardcode) or when I was trying to use DMF6....I always used the Subtitle Workshop program to make sure the timings of the srt subtitles were correctly synched with the avi file (I menitoned that in my initial post). SEVERAL times in DMF6, I've run off DVD's and the subtitles have ALWAYS gone out-of-synch as the movie progresses.....and no matter what I do, even altering the timing directly in DMF (you know where that can be done), they ALWAYS go out-of-synch.

Something is not right or working correctly in DMF6 when I load a video file and the separate subtitle/SRT file.....they don't stay correctly synched throughout the movie upon completion of the final disc. In Preview mode, however, the subtitles STAY in-synch. This is why I've basically given up on even trying any further to do optional subtitles in DMF, and have gone with hardcoding them to the AVI file prior to running my DMF project.....but I would like to know why they don't stay in-synch through DMF. Technically, they SHOULD.

Why is that?

NOTE: (Addendum) What I meant above is that I make sure the frame rate and timing of the srt file matches the frame rate of the AVI video. I just now checked a project I haven't done anything with yet (both the subtitles and the AVI are at 23.97 frame rate), and noticed that the default project/MPEG settings is for 29.97 frame rate. Is it possible THAT makes the difference, and the reason why the subs go progressively out-of-synch on my final DVD? This is the first time I've noticed that, and realized that might possibly be the problem. If this is, what would I want to change in the project to make the frame rates match up....the frame rate of the MPEG settings (which wouldn't make sense to me), or the frame rate of the srt subtitle file so that matches the project frame rate of 29.97?

[sj1805]

....
NOTE: (Addendum) What I meant above is that I make sure the frame rate and timing of the srt file matches the frame rate of the AVI video. I just now checked a project I haven't done anything with yet (both the subtitles and the AVI are at 23.97 frame rate), and noticed that the default project/MPEG settings is for 29.97 frame rate. Is it possible THAT makes the difference, and the reason why the subs go progressively out-of-synch on my final DVD? This is the first time I've noticed that, and realized that might possibly be the problem. If this is, what would I want to change in the project to make the frame rates match up....the frame rate of the MPEG settings (which wouldn't make sense to me), or the frame rate of the srt subtitle file so that matches the project frame rate of 29.97?

Exactly what I was getting at, by using a different frame rate you are altering the duration of the video and so throwing the timing of the subtitles out.
Read my first reply again.

[DVDDoug]

If this is, what would I want to change in the project to make the frame rates match up....the frame rate of the MPEG settings (which wouldn't make sense to me), or the frame rate of the srt subtitle file so that matches the project frame rate of 29.97?

If you're making an NTSC DVD (to be played on North American DVD players), it must be 29.97FPS.

I don't fully understand the 20 second error. If the SRT times match the true-times when the NTSC video is played-back, I don't know why it would be off.

It could have something to do with the fact that PAL video is actually played-back at 25FPS. This means that the PAL version of a movie plays-back a little facter than the NTSC version, and it's usually a couple of minutes shorter. But, I'm not sure if that's the source of the problem, since the difference between 25 and 23.97 is more than 20 seconds over a typical 90 minute movie...

[pkh]

I also ran into this subtitle gradually go out of sync problem. I use ts and external srt file to create a HDDVD. Subtitle is right at start of movie but off about 10 seconds towards the end. There is no reencoding going on when making the HDDVD folders. The original ts and external srt all plays fine. Seems to me the movie is either running faster or subtitle is not following the time code in the srt file.

Is there a fix or I have to stick with hard burn subs?

edit: found a solution. I change the fps of srt from original 23.976 to 24 using Subtitle Workshop seems to keep the sub in sync. But don't know why the HDDVD is being sped up by MF6.

[montgal55]

Hello sj1805:

So the key is the framerate that should correct out-of-synch subtitles issues

Interesting, I will kept that in mind (I am currently working on a .avi subtitle project now myself).

I am noticing that many movie files (.avi) have varying rates from 25 to 29 fps.

Montgal55_NYC