DVD2AVI and delays in AC3 files

[kimpen]

I'm getting crazy....

I really don't understand why DVD2AVI in a ripping process, I mean when I'm saving a .D2V project from a DVD that later I pass to TmpgEnc, generates audio files .Ac3 with DELAYS....

This happens if I don't start the ripping at the beginning of the movie: let's say I divide the whole movie in two parts, and decide to demux only one track from the original vob files. What happens is that the first part of the movie generates an audio file .ac3 WITHOUT a delay; the second part of the movie ALWAYS contains a delay that can go from 40ms to 240ms !
The delay depends on the point in which I start the ripping process...

When I go to multiplex the resulting video and audio files, the first part of the movie is ok, the second is not sincronyzed!

Now... is it possible to null the delay in the demuxed ac3 audio file?
I need it because I want to make a miniDVD and the authoring program wants the video and audio track separated!

Thanks in advance!

Kim.

[AntnyMD]

Just ignore the "delay". DVD2Avi gives too much information in the file name of demuxed AC3 files, and it just scares people. Dont fret about the delay, dont fret about the file name, just encode your video, call it movie.m2v, rename your demuxed AC3 file movie.ac3, and drop them into your DVD authoring program.

They sync will be alright, and you can test the DVD structure and quality before you burn, anyway.

[kimpen]

Thanks for the answer but... I have tried MANY times, with different audio files;
If I have a 40ms delay everything is ok!
If I have a 200ms delay I see in the authoring system, in the preview phase, that the audio and video are not syncronized!
I assumed that the first case is trascurable, but the second case not!

Obviuosly I stopped me to burn the final miniDVD in the 2nd case...

Are you telling me that after the burn, everything is ok even in the second case???

Bye,
Kim.

[kimpen]

x AntnyMD

I've just burned a cd-rw after the authoring phase with SprueUp and the resulting movie... is bad!

The original .ac3 was affected by a delay of 240ms and the resulting miniDVD contains audio and video not syncronized... the video before.. the audio after!

So definitively, I must take care of the delay!!!

The problem is... how to correct it???

Any suggestion?

Bye,
Kim

[stanwebber]

ignoring the delay dvd2avi reports off the dvd is foolhardy. the delay exists on the dvd & is not a product of dvd2avi's demuxing routine. 40ms is imperceptible hence you dont notice the async. try muxing in bbmpeg & adjust the startup delays to compensate(azid section on my homepage has instructions at the bottom)>demux in tmpgenc or bbtools. although i'm surprised your dvd authoring software lacks this function, but what do i know?

[kimpen]

In my understanding and few tries, using bbmpeg is possible if you want to obtain a final mpeg file wich contains audio and video track multiplexed (I think you can even use TWO audio tracks). But this is not my case!

Infact I need the audio and video tracks separated because SpruceUp wants them (.ac3 and .m2v) separated to generate the final .vob files!

Furthermore, I'm not quite sure about you assertion regarding DVD2AVI!

I tried to see the source code of the program and from my poor knowledge of mpeg concepts i deduced that 'cutting' a part of a movie, when ripping a vob files, is done respecting the video information and not the audio! This should be the cause of the 'always present' broken frame you find at the end in the audio file after a demuxing operation; in this case infact you need to use a program like Ac3fix that eliminates the final incomplete frame in the ac3 audio flow.


Bye,
Kim.

[Wandering Youth]

I have simliar probably with some of the DVDs I tried to ripped in the past. How do you use the demux thing in TMPEG to fix this syncing stuff?

[jmproductions]

I'm having the same problem. how do you fix the delay when you mux. I got one work by re opening the project up in dvd2avi and setting my start point ahead about 20 frames and saved the project and just the ac3 file from it and my orginal video file and it was in sync, but there has to be a better way!
thanks

[kingsley]

http://www.doom9.org/Soft21/Audio/ac3delay_all.zip

Thanks to doom9.........