Duration & AV sync issues with the VOB file - ripped from DVD

[streamingguy]

Hello,

I am ripping few DVDs using DVDDecrypter and DVDShrink. I am creating single .VOB file for the whole movie, instead of creating different VOB files for each chapter/1GB size.

When I try to play the .VOB file, I see different duration values on different players (VLC, Media Player Classic, Windows Media Player, FFMPEG log, MediaInfo).

Also, I see av sync issues. If I do forward/rev few times, I see more delay between audio & video.

Any suggestions to avoid av sync issues and to get correct duration values? I am trying to encode this .VOB file into MP4 and the delay is carried out on MP4 files and I see more delay than in VOB file.

Please let me know, if you need any other information.

Thank you for your valuable time and great help!

[hech54]

Use VOB2MPEG if you want one, giant MPEG file.
Stop messing with "VOB" files once they are removed from the DVD.
I've also found clip duration errors in VLC...it's rarely correct.

[streamingguy]

Hello hech54,

Thank you for your quick reply. I will try VOB2MPEG and see whether it fixes the issue.

As of now, I am extracting DVD into VOB file using DVDDecrypter and then coverting it to MP4 using MeGUI & AVISynth scripts. I am also creating 6 different variants to use them in adaptive streaming. Do you suggest any better way for the whole process?

[hello_hello]

When converting using MeGUI it should use DGIndex to index the vob file(s) while extracting the audio stream(s) in the process. The amount of audio delay (if any) should be written to the name of the extracted audio stream and automatically applied by MeGUI when muxing the audio stream (or the encoded audio) into the final MP4 output file. The process should work perfectly as long as the original DVD was ripped correctly.

Assuming you're using DVD Shrink to re-author the ripped files as just the movie.... with DVD Shrink set not to split the vob files..... that shouldn't cause a problem, but letting DVD Shrink split them into 1GB segments it also fine. When you open the first vob file using MeGUI it'll automatically include the remaining sequentially numbered vob files, and that's perfectly normal.

Anyway.... media players displaying different/incorrect durations when playing vob files isn't anything out of the ordinary, although I don't know why it happens. It shouldn't stop MeGUI from indexing and encoding the movie correctly though. Generally the audio should still be in sync though, so maybe the first thing to try would be to use a different method to rip the DVDs. DVD Dectrypter is old and may not be handling any copy protection correctly. Maybe try ripping it with the free version of DVDFab, or use DVDFab to run in the background and decrypt the disc while you open it directly using DVD Shrink.

Audio sync issues when encoding may also be caused by MeGUI applying the wrong type of de-interlacing or IVTC when analysing the video but I'd start by eliminating the ripping process as being the cause.

[streamingguy]

hello_hello,

Thank you so much for your detailed information and for your time!

I am using DGIndex to index VOB files and then executing AVISynth scripts to de-interlace & apply watermark. Earlier, I thought MeGUI is causing the av sync issues. But, after looking couple of sources, I found out that, I have av sync issues even in the source VOB file.

I will try the different ripping procedures mentioned by you and post my results ASAP.

Thank you once again!

[streamingguy]

Hello hech54 & hello_hello,

I tried the ripping with VOB2MPEG and still had av sync issues. The problem may be with the source itself. I will try with few more DVDs and see if I have the same issue.

But, When I played MPG file (after ripping from VOB2MPEG), I see proper duration values in VLC and Media Player classic.

Thank you for your time!

[hello_hello]

The DVDs you're ripping..... are they movie DVDs or episodic DVDs?

When ripping, or after ripping, ideally you'd want to re-author the DVD so the ripped files you're converting are just the vob files for the movie only, or ripped so that each episode is a separate set of vob files which you'd convert individually. If you join the vob files of an episodic DVD together when ripping, for example, and convert all episodes together, you'll probably have audio sync issues.

If you try different DVDs and still have audio sync issues, you might have to explain the ripping process you're using in more detail in order for someone to help you work out what's going wrong. And you might have to be a bit more specific about the audio sync problem you have. ie whether it's out by the same amount for the whole movie, progressively wanders further out of sync as the video progresses or if the audio sync changes in "steps" etc.

[streamingguy]

Hello hello_hello,

Thank you for your reply.

My DVDs are regular movie DVDs. Below are the steps I performed to rip the DVDs/encode them to MP4.

1. I loaded the physical DVD into my DVD drive and used SlySoft AnyDVD to save the DVD into .ISO file on my HDD.

2. Then, loaded the .ISO file using SlySoft Virtual Drive and then through DVDShrink, I selected "Re-Author" and added only the movie "Title" to the re-author list. I am not splitting the VOB files and hence the output from DVDShrink has a large/single VOB file.

3. Then, I loaded the VOB file into MeGUI --> Indexer --> AVISynth Script --> Video Encode --> Audio Encode --> MP4 Muxer.

For few DVDs, I opened the first .VOB file from .ISO file in MeGUI, which automatically selected other .VOB files and loaded the whole movie.

For few other DVDs, I prepared single .VOB file using DVDDecrypter and then loaded it into MeGUI.

I even tried by preparing .VOB file in DVDDecrypter without using SlySoft AnyDVD in between.

But, the outcome is same for all the encodes/VOB files.

The delay is not same for the whole movie. It changes in "steps". For some part of the movie, it is in sync and then next 10 minutes, we have sync issues. The delay is also not huge. It is around 0.4 seconds or less than that. But, you can clearly observe it.

Please let me know, if you need any other details.

Thank you for your time!

[hello_hello]

It doesn't seem like you're doing anything wrong, although you could probably save yourself some time by bypassing the ISO stage when ripping. Generally I just let AnyDVD run in the background to decrypt the disc "on the fly", open the disc directly with DVDShrink, then re-author and rip it in a single step. From there I just open the vob file(s) for encoding, and while very occasionally there's an odd problem, the process basically works correctly 100% of the time.

Anyhow, it occurred to me to check the MeGUI thread over at doom9 and I found a post where someone reported a similar problem very recently. http://forum.doom9.org/showthread.php?t=151159&page=133 (post #2657). If it's an MeGUI bug then you might have to experiment a little to find out if a particular tool MeGUI uses is causing the issue. I'd try indexing the vob file and extracting the audio then converting only the video. Once it's converted use MeGUI's muxer (or MKVMergeGUI) to manually add the extracted audio to the encoded video and save it as an MKV. If that works okay, then try remuxing it with the extracted audio as an MP4. If that's still okay and you've been converting the audio, try converting it and manually muxing the encoded version with the encoded video etc etc. At least that way you should be able to determine if it's the muxing process which is causing the problem.
I pretty much always use MKV but I have two PCs with MeGUI installed, both running the same version of Windows. I had to roll back MP4Box to an older version on one PC to get it to mux MP4s without error a while back. Why.... I have absolutely no idea. The latest version of MP4Box works fine on the second PC.

If none of that works, maybe use DVDShrink to re-author a small section of the vob file you're having problems with and upload it somewhere for others to download and look at. One which produces an audio sync problem when you re-encode it. Just 5 minutes would do. Or maybe try posting the script MeGUI is creating when converting a problem DVD to see if there's anything obvious there.

Short of any of that helping..... my next step would be to try converting a problem DVD using another program. Generally I'd use AutoGK and convert it to AVI, as in the "always gets it right" department, AutoGK is the most reliable GUI I've used. It works the same way as MeGUI.... demuxing and indexing using DGIndex with AVISynth frameserving. You could just run a single pass encode to see if the resulting AVI has the same audio sync issues, and if it doesn't have a look at the script AutoGK creates to see if it's it's doing something different. I've done that myself a few times, although to sort out de-interlacing/IVTC issues rather than audio problems. If the AVI AutoGK produces does have the same audio sync issues then it's likely the problem is with the source video or ripping process rather than being a result of the encoding process.

Sorry I can't provide an actual solution. Given the process should work I guess it's probably a matter of trial and error to find the cause. At the moment I'd place my bet on the problem being caused by the muxing process but anything's possible. If you find the culprit please let us know.