VirtualDubMod - Does it keep audio sync?

[vodmare]

It doesn't appear to do audio at all. But in the version updates theres the mention of audio fixes.....

Is it possible to use this, convert from .vob at 23.976 frames to an .avi at 23.976 frames and keep the audio in sync?

Thanks.

-vodmare.

[redwudz]

Audio doesn't have a framerate, just length, so it should keep the correct sync. But other things can cause sync problems. Missing frames, bad cuts and pastes, VBR audio, video framerate changes, etc. None of those should have much affect on a VOB file, though.

The most common audio 'fix' is adjusting the audio/video offset. VDM calls that 'Audio skew correction' and it's in thousands of a second, plus or minus. It's under 'Streams>Stream list>Full Processing mode>Interleaving'. It's used when the sync error is the same throughout the length of the video. When the sync error changes throughout the video, that's commonly caused by the audio/video lengths being different. (Or one of the above mentioned problems. )

One note also, if you are converting the audio to MP3 with VDM. You may want to add Lame MP3 ACM to have a full range of MP3 options.

[manono]

And if there was a delay in the original audio, unless you take that into account your audio will become out of synch after a conversion. Just dropping a VOB into VDubMod and encoding to something or other isn't such a good idea, if you expect the audio to remain in synch. And if you do it that way, try and find out if there's a delay in the audio so you can figure for it.

And NTSC VOBs aren't 23.976fps, although VDubMod ignores pulldown. They're 29.97fps.

[vodmare]

I thought movies that were converted from film to DVD were 23.976........

And every movie that I have ever converted goes out of sync, it's never been a problem to just adjust on the fly while I'm editing. But I wanted to see if there was an alternative. No bad frames, no cuts, no errors in the video that I have come across. It just goes out of sync, with the video every time.

Someone mentioned that a .vob file may have both 23.976 and 29.97 frame rates in it and if you turn the flags off it will definitely go out of sync. The only problem is if you turn it on, it changes the frame rate to 29.97 and displays it as interlaced.

Any ideas?

I am going to see how the interleaving fix acts. Thanks!

[manono]

Any ideas?

Sure, lots of them. But I'm not sure you've understood the lessons you received from jagabo in your other thread.

Someone mentioned that a .vob file may have both 23.976 and 29.97 frame rates in it and if you turn the flags off it will definitely go out of sync.

That it will, and that's one reason (of several) why I said it's not a good idea to just drop a VOB into VDubMod and expect the audio to be in synch after encoding.

I thought movies that were converted from film to DVD were 23.976........

All movies on NTSC DVD output interlaced 29.97fps. Even if they were encoded as progressive 23.976fps (as is often, but not always, the case), the 3:2 pulldown that's applied tells the player how to output the interlaced 29.97fps (really 59.94 fields per second).

My suggestion is to decrypt using DVDFab HD Decrypter in its Main Movie mode (or DVD Decrypter in IFO Mode if it's an older DVD) and then open the IFO of this film (or, as a second choice, the VOB(s)) in AutoGK and let it do the job right.