Audio Conversion out of sync

[Silsur]

I have been unable to find a definitive answer to my problem anywhere in these forums.
I have a nuber of Vobs with AC3 6 channel audio.When I convert any of them to Avi(Divx etc.)
the audio is always well out of sync by the end of the video.
The video and audio have identical framerates and run times etc.
Ihave tried Vdub, or demuxing with various programs aand using Besweet and similar programs but always
finish up with desynced videos.I have a used a variety of methods suggested in these forums to resync videos to no effect.

[usta]

For me VOB to AVI conversion runs nicely in sync with Handbrake.

[Silsur]

Thanks for your suggestion Usta,however,I d/loaded Handbrake late last night,tried several files this morning and all of them
hang at some point in the process.
I am including some more detailed info in this reply.
Original files; Video NTSC 23.976
Audio AC3 5.1
Perfectly in sync.
Tried Vdub,Divx,Avidemux,and Handbrake to convert to Avi.with Stereo MP3. All finished up completely out of sync.
Next Tried demuxing,converting audio with Besweet,remuxing. Still finished up out of sync.
Both methods have framerate and runtime set identical.
Tried varying both video fps and audio runtime to no avail.

[guns1inger]

Where did the VOBs come from ?
Did you rip them yourself ?
If so, how - software/process etc ?

I have never had a sync issue using AutoGK to convert VOBs or MPG files.

If you are having problems with multiple programs then you have a larger issue, either with your system, or with your process prior to converting.

[Silsur]

Hi Gunslinger,I ripped them using DVDFab Decrypter.I have been converting files successfully
for several years to use on my Archos box but this is the first time the files have contained
AC3 5.1. They have usually been AC3 2Channel and when i've had some sync problems
on occasions advice from forums like this has solved them.

[Silsur]

Gunslinger I've just tried AutoGK and it has successfuly converted one file with no sync problems what so ever.
Out of curiosity is it possible I have created a program or codec conflict without realising it. In which case I need to have a clearout of programs and codecs. Now it's on to the next file and I can carry on growing old gracefully.
THANKS VERY MUCH FOR YOU INPUT.

[usta]

I must add, that I have AC3Filter installed on my system.
Maybe that is what kicks in Handbrake conversion process to keep DVDs with AC3 audio in sync...

[filmboss80]

What were your encoding settings? It's best to choose CBR (constant bitrate). Depending on the player, an audio stream encoded in VBR (variable bitrate) has a greater tendency to drift out of sync.

[guns1inger]

In this case the OP is attempting to keep the original AC3 audio while re-encoding the video only, so VBR should not be an issue.

Otherwise, sound advice.