Extracting AC3 tracks from VOB wth DVD2AVI

[DRP]

When I do this, I get an AC3 file out which has a name with an audio delay figure at the end of it.

For example I have just done one with the figure "AC3 T01 3_2ch 384Kbps DELAY -80ms" at the end of it.

I want to use this audio track in creating an SVCD. What I typically do is open the track in GoldWave and then resample/volume maximise in there and save out as WAV before going ahead and doing the SVCD creation.

How do I compensate for this DELAY figure to maintain perfect audio sync in the end result SVCD? I know that 80ms is such a small amount that it won't be noticeable anyway, but I have seen some other extractions with figures as high as 500ms before which definitely would be noticeable, so I'd like to learn how to do it properly.

I assume I need to use the "Insert Silence" option in GoldWave. Do I just add 80ms of silence at the very beginning of the track to compensate correctly? Or do I have to *remove* 80ms from somewhere?

Thanks,

DRP

[Tommyknocker]

If delay is truly what the audio is talking about, it means the audio starts 80 ms later than it should. So to remedy this, you have to delete 80 ms from the start of the audio. However, if the DELAY value is is expressed in negative/positive numbers, "-80 ms" means the audio starts 80 ms sooner than the video. Here you would add the 80 ms of silence. The only way to know for sure is to grab the 500 ms delay audio and see what they are talking about.

[FulciLives]

You have a several options on removing the delay.

1.) Use BeSweet to convert the AC-3 to a WAV file. It can compensate for the delay value. It should also be able to downsample from 48k to 44.1k but you could always just to to a 48k WAV file then do the downsample in a WAV editor ala GOLDWAVE.

2.) Same as number 1 but instead of BeSweet use HeadAC3he

3.) Use the program called AC3 Delay Corrector which will make a copy of the original AC-3 file to a new AC-3 file that will have the delay adjusted to 0 (aka ZERO). Then use the method you have been using but with the new AC-3 file.

Good Luck!

- John "FulciLives" Coleman

[DRP]

3.) Use the program called AC3 Delay Corrector which will make a copy of the original AC-3 file to a new AC-3 file that will have the delay adjusted to 0 (aka ZERO). Then use the method you have been using but with the new AC-3 file.

That's great! Thanks for that. It sounds like just what I'm looking for.