How to fix the audio delay in Avidemux? (or in original .vobs)

[Fañch]

Hi everyone,

Here's the issue I have for some days now:

I want to encode in mp4s DVDs I ripped, and all of them end up after the encoding process with a specific audio delay. Delay which I want to get rid of eventually.

Here's the steps I follow:

- I rip the DVD using AnyDVD (7.1.3.0),

- I get the classic VIDEO_TS folder in which I find the .vob files I use for encoding

- I encode using AVIDEMUX 2.5.6 (2-pass encoding, no delay option ticked, same output) ; H264/AAC codecs in a mp4 container,

- Checking the resulting file, MediaInfo reveals the following: "Delay relative to video: 80ms".

Should I tick the delay box and take off 80ms and encode again, it doesn't change the resulting delay anyway.

Looking back with MediaInfo at the different .vob files I have, most of them have a delay mentioned in the audio - like this one for instance:

VTS_02_1.VOB: no delay
VTS_02_2.VOB: -448ms
VTS_02_3.VOB: -560ms
VTS_02_4.VOB: -496ms

I'm not a specialist but I suppose this delay is somewhat normal as I tend to find it on most .vobs I get after ripping.

Should I encode from one single .vob only (with MediaInfo not mentioning any delay in the latter), 80ms delay is still appearing in the resulting file.

This situation makes me wonder if the issue is not coming from my own hard/software. But I did try out other versions of Avidemux (2.5.6.0, 2.6.0, 2.6.1 - all three in both 32/64-bit - plus portable version) and it would either crash (the latest versions, presumably because of the 2-pass encoding) or end up with the mentioned delay.

This leads me to 2 questions:

- Does anyone know where this audio delay to video could come from? (the ripping? Some Avidemux's option not properly set? Some MediaInfo bug?? [which I doubt])

- Does anyone know how to fix this delay? (Should I edit the .vobs in some specific software or something? Or demux the audio, resynch it somewhere else before remuxing it in? That one sounds pretty painful if it must be done for every ripped file)

Thanks a bunch if you guys can help me see clearer on this matter.

P.S. I also tried Handbrake but couldn't get the encoding process above a ridiculous amount of %. Yeah, I'm not familiar with this one yet.

[AlanHK]

VOB files really aren't meant to be used as stand-alone media files.
They sometimes have a delay, which is specified in the IFO.

It might be better if you converted the VOBs to MPEG files first. This is pretty fast and lossless.
I like ReJig, which is very old but does the job. (Use IFO mode, and tick "Correct AC3 delay").
Also VOB2MPG does this.

[manono]

Should I encode from one single .vob only (with MediaInfo not mentioning any delay in the latter), 80ms delay is still appearing in the resulting file.

No, do the whole thing at once. The delay for every VOB after the first is a non-issue. I don't use AviDemux so don't know if its delay is correct or not. I'd much rather trust PGCDemux or DGIndex in that regard. You say you're getting full DVDs out of AnyDVD so open the right IFO in PGCDemux and check the 'A/V Delay' there. My guess is there is none at the start of the movie.

[hech54]

Stop messing with VOB files. VOB files are only meant to exist in a DVD environment. Put them back to their original MPEG2 status before editing or converting.
VOB2MPEG is probably the easiest.

[Fañch]

Thank you for all your answers.

All well-noted regarding the idea of putting back the .vobs into Mpeg2. Which I did.

As proposed, I first loaded my .ifo and converted what needed to be converted into .mpeg with VOB2MPEG. Then encoded that .mpeg in AVIDEMUX again - but I also ended up with the same 80ms-audio-delay-over-video notification by MediaInfo.

I then checked with PGCDemux, which indeed finds "A/V Delay: none" in my .ifos.

I really don't get it. Where is that (indeed short, but still) delay coming from if it does not exist in the first place?

Now from here I don't know where to go.

[hech54]

Are you actually SEEING a delay when you play the MPEG in AviDemux, or are you just relying on what a program's stats tell you?

[Fañch]

I know the impression could come because of that MediaInfo statement, but I actually do see one, yes. Just checked with several rips I've done and the delay's there, quite obvious to me at some points even.

EDIT:
Sorry, that was when playing the MPEG in VLC!
It seems to play just fine in AVIDEMUX

[Fañch]

Ok, it seems this audio delay bug was pointed out already back in 2007 : http://www.avidemux.org/smf/index.php?topic=2948.0

So I just decided to go for another writing library/encoder (AVS video converter for those who wonder), which actually encodes fine for the file I am working on.

Will now wait for Avidemux to do something about it...