IDX/SUB Files Extracted from Anime DVDs with VobSub Out of Sync

[CarlEdman]

I am having the following problems with subtitles in IDX/SUB format extracted from a substantial number of my DVDs.

VobSub 2.23 (a few years old, but the most recent I've ever found) extracts a complete set of subtitles files in IDX/SUB format from the VOBs. These subtitles are initially in sync with the video/audio, but at one or more Vob/Cell boundaries the subtitles suddenly fall behind anywhere from a few seconds to a few minutes. That is, the IDX file inserts an additional, incorrect gap in the subtitles. From the first gap on, the subtitles go out of sync with the video/audio and each additional gap later on puts them further out of sync.

While this problem occurs with only a minority of my DVDs, it seems especially prevalent on Anime DVDs (typically Japanese sources, but commercially created for U.S./Region 1 market).

This is particularly frustrating as I *know* that it is possible to extract the correct timing from the VOB file. Other software which plays the VOB directly and can display subtitles, such as DVDSubEdit has no problem displaying the subtitles at the correct time throughout the VOB.

One suspects that the ultimate source of the problem is some error in mastering the DVDs which most other software, but not VobSub, can compensate for.

Can anybody recommend any solution for my problem?

I realize that I can just edit the IDX file (either directly or by interspersing Delay: statements), but this is both (1) time-consuming when there are many little gaps in a single DVD and (2) dependent on my exact timing and so probably does not result in quite perfect sync.

A perfect solution would just replace VobSub with another tool that can be used to automatically extract IDX/SUB subtitles from VOBs. VobSub is plenty frustrating already, so replacing it completely would be nice. (I'm quite happy with image-based subtitles and switching to a text-based format which OCRs the images in my experience is more error-prone and labor-intensive than the savings in space justify.)

A good solution would just somehow extract the correct timing of the subtitles in a readable format. With the correct timing, I could just write a script to automatically fix the VobSub-created IDXs.

Thanks for any advice!

[CarlEdman]

Anybody? Surely I cannot have been the first to encounter this problem and somebody has come up with a solution.

What do people on Linux/Mac use to extract IDX/SUB titles from their DVDs? Surely it cannot be VobSub and, if it is a command line tool, it may be possible to port it to Windows fairly easily.

[stax76]

I had a DVD where vsrip would produce sync issues, all settings and ripping methods tried, nothing helped.

Only thing working was demuxing subtitles using ProjectX.

[Ghitulescu]

These subtitles are initially in sync with the video/audio, but at one or more Vob/Cell boundaries the subtitles suddenly fall behind anywhere from a few seconds to a few minutes. That is, the IDX file inserts an additional, incorrect gap in the subtitles. From the first gap on, the subtitles go out of sync with the video/audio and each additional gap later on puts them further out of sync.

I think I remember this issue from one of the video fora I am member of. But I don't use vobsub (and didn't). I simply use pgcdemux or vobsubrip (for CC only) if I ever need a subtitle.

[CarlEdman]

Thanks for the suggestions, Stax76 and Ghitulescu!

For what it is worth, here is my experience with these programs:

(1) VSRip produces .idx/.sub files with timings even much worse out of whack than VobSub, so it does not appear to be a solution.

(2) PGCDemux produces only .sup file subtitles which MP4Box cannot deal with. Is there a converter or other way to get these subtitles into a .mp4/.mov file?

(3) Avidemux is the only tool that appears to produce .idx/.sub files with something that eyeballs as being close to correct times. Unfortunately, mp4box chokes on the .idx/.sub files produced by avidemux. It produces copious messages about corrupted .idx/.sub files and either fails completely or produces an .mp4 file which crashes VLC on startup.

(4) Project-X appears to be a complex tool. Is there a guide for using it to extract .idx/.sub files from an .ifo/.vob combination?

Thanks again for the suggestion and please keep them coming!

[Ghitulescu]

I think that for mp4box the people here use SubRip to get the subtitles as SRT and there is definitively at least one SRT->IDX/SUB converter (I don't recall right now its name) should MP4box cannot properly deal with SRT.

I cannot help you more info than this: reports are that animes often have a variable format (progressive, interlaced, 24p, 59.94i and so on within the same episode). Maybe this odd form and its associated timing can cause you troubles.

I don't use anything but industry-endorsed formats, I explained several times why.

[stax76]

Is there a guide for using it to extract .idx/.sub files from an .ifo/.vob combination?

Yes, here it is:


add files: File table > add files (button with green plus or drag & drop)
enable option: Filter Control > more settings > Subtitles > additional export as VobSub
start processing: click the 'Quick Start' button

[manono]

1. Get the subs as SUP files using PGCDemux.
2. Convert instantly to VobSubs using SubtitleCreator.

[CarlEdman]

Thanks for the suggestion, manono. I did not know Subtitle Editor could do that.

Unfortunately, PGCDemux itself already barfs on the source files (.IFO/.VOB). No matter what it is told to demux, it proceeds up to a certain percentage (between 10% and 40%), pauses, and then claims to have completed the job successfully. However, the resulting demuxed files are, obviously by their sizes, truncated (roughly at the final percentage displayed by PGCDemux).

[stax76]

Another method would be ripping with MakeMKV and then demux audio and subtitles with mkvextract, StaxRip and RipBot264 do this automatically, works great with many DVD structures that would cause all kind of sync problems with the traditional ways.