Converted VOBs to AVI via DGIndex/VDub, Audio Gradually Desyncs

[koberulz]

I opened all the VOBs on a DVD in DGIndex, created a d2v and ac3 file, opened the d2v in VDub with AviSynth and exported as an AVI. Imported the ac3 and AVI into Premiere, but the audio gradually goes out of sync over the course of the video. The sync issue is not present on the original DVD.

Where might I have gone wrong here?

[sneaker]

Do you have "Video"->"Field Operation"->"Honor Pulldown Flags" set in DGIndex? Is the AviSynth script in-sync if you play it using e.g. MPC-HC? Post the script. Post your VirtualDub video encoding settings. Did DGIndex report any delay for the ac3 audio (usually written into the filename of the ac3)? How did you create/rip the VOBs? Did you use one d2v file for all VOBs or one for each?

[hech54]

I opened all the VOBs on a DVD in DGIndex, created a d2v and ac3 file, opened the d2v in VDub with AviSynth and exported as an AVI. Imported the ac3 and AVI into Premiere, but the audio gradually goes out of sync over the course of the video. The sync issue is not present on the original DVD.

Where might I have gone wrong here?

Sounds like a ridiculously convoluted process just to get video that can be imported into Premier for editing.

[koberulz]

It's a crappy DVD-recorder digitisation of a VHS tape. So AviSynth also fixes the levels, and VDub crops off the head switching noise.

Honor Pulldown Flags is set.

The AviSynth script has no audio. It just loads the d2v with MPEG2Source() and then SmoothLevels(0,1,255,16,235).

I'm saving as Lagarith YUY2, which I've done fine on many other occasions.

The audio file has a 64ms delay, but without even bothering to adhere to that it starts out roughly in sync and ends up out of sync by a second or two.

I just copied the VOBs from the disc to my PC.

One d2v file.

[poisondeathray]

Add the audio to script, save uncompressed audio with the AVI

You can also test for sync before importing into vdub by playing script (you can comment out your filters if your computer too slow), or after by playing AVI

[koberulz]

How do I import AC3 in AviSynth? Googling shows something about NicAudio, but it's a decade old and links seem dead.

[sneaker]

ffms2 (Last official build is a bit old but development is active.)

a=ffaudiosource("source.ac3")
v=mpeg2source("source.d2v")
AudioDub(v, a)
#DelayAudio(-0.5) # delay audio by e.g. -0.5 seconds if necessary

It can also directly read AC3 and other audio formats from various containers (mkv, mp4, avi, ts ..).

[koberulz]

Sync drifts in the AviSynth script.

[poisondeathray]

Sync drifts in the AviSynth script.

Did you take out all the other filters? ie. Just keep video and audio for testing purposes for now . Test in MPCHC

[koberulz]

Here's literally the entire script:

vid = MPEG2Source("VTS_01_1.d2v")
aud = ffaudiosource("VTS_01_1 T80 2_0ch 256Kbps DELAY 64ms.ac3")
dubbed = AudioDub(vid,aud)

return dubbed

[manono]

Does this thing have more than a single VOB ID? You can find out in PGCDemux. The reason I ask is if each has delays, those delays will accumulate as the video goes on. If, for example, each cell (chapter) is also a VOB ID with delays for each, then that's the cause of your problem. I've never examined a DVD made from a DVD recorder so I don't know.

[koberulz]

It goes from VTS_01_1.VOB to VTS_15_1.VOB, if that's what you mean?

[manono]

No, not what I meant. The VOB ID. Open the IFO in PGCDemux and tick 'by VOB id'. In the drop down box you can see if there's more than one and the 'Check A/V delay' button will show you the delay for each. Admittedly, I'm clutching at straws here because I don't understand the cause of the problem. A bunch of VOB IDs with delays will definitely cause it. The most I've ever seen is 2 VOB IDs (except in episodic television shows), and it messed up both the audio synch and the subtitle timings after the change of VOB IDs.

I don't have an example to show you because retail DVDs don't often have problems like this. But I know nothing about how DVD recorders behave.

[koberulz]

Each IFO lists VID 01 (01), with a delay of "0x80 --> 0msecs".

[manono]

Okay, it's not what I was thinking. Thank you for checking. But...

Each IFO? This 15-VOB video has an IFO for each VOB? Or what? Because it might work the same as multiple VOB IDs. If there are multiple IFOs and multiple VOBs, and you're joining all VOBs and joining all Audios (as you would if getting the audio from DGIndex), and if the audios aren't exactly the same length as their corresponding VOB videos, that's a recipe for audio asynch.

You can confirm (or disprove) the theory by finding the exact lengths of one of the VOB videos and one of the VOB audios. If slightly different, it's not a gradual asynch, but every time a new VOB begins you'd get a little 'jump' of asynch. Individually it might not be much (100-150ms or so), but it can add up to the amount you mentioned at the beginning.

[koberulz]

One IFO per VOB, yes. The guy who made it stopped recording at the start of each commercial break, so it's 15 separate 'titles'.

Guess I'll have to pull the VOBs into Premiere and then go out to VDub, then.

[manono]

One IFO per VOB, yes. The guy who made it stopped recording at the start of each commercial break, so it's 15 separate 'titles'.

Guess I'll have to pull the VOBs into Premiere and then go out to VDub, then.

I think you can probably do it using AviSynth's AlignedSplice. But you'll have to append all the separate audios and videos. If I'm correct (not guaranteed), each audio is shorter than the corresponding video for each VOB. AlignedSplice will add the necessary amount of silence to bring the audio up to the same length as the individual VOB videos. And that should keep everything in synch. I'm now convinced your synch problems are due to there being 15 VOBs for this single video.

You mentioned NicAudio earlier, so I'll include it. It works well for opening AC3 audio. Once it's in an AviSynth script, though, you'll have to save the audio as WAV audio and then reencode afterwards.