Audio synchronization solved?

[Creeping Death]

Hello all,

I've been making backups of my DVD collection using DVD Decrypter (IFO mode) and AutoGK. I convert the DVDs to AVI files using Xvid.

For the most part, I've had no problems. However, I ran into audio synchronization issues with the following:

The West Wing Season 3 (Isaac and Ishmael)
Sin City Recut
Pixar shorts (Luxo Jr, Geri's Game, Mike's New Car, etc.)

In all cases the audio is delayed from the video in the final AVI. I searched this forum and others for some fixes, such as demuxing the audio and video and remixing them together with a delay. The problem I encountered was determining the correct offset.

For example, Isaac and Ishmael opens with a graphic that's shown for about five seconds. The AVI file has a single frame of the graphic, but the audio stream still contains all of its frames.

Recently, I had an opportunity to try ripping these again. And during the ripping, I noticed something odd in DVD Decrypter.

When I look at the PGC stream in DVD Decrypter, I noticed some additional cells in the first chapter. In the case of Isaac and Ishmael, there were two cells, one of which was five seconds long. I cleared the checkbox for that cell and re-ripped the episode. When I encoded it with AutoGK, the audio was synchronized.

I used the same technique with Sin City Recut and the Pixar DVDs and the audio came out synchronized once I figured out which cell to ignore during the rip.

(Strangely enough, the regular Sin City DVD rips normally and there's no audio delay.)

I'm not sure if this technique will work for other DVDs, but I thought I would share with everyone and see what the community thinks.

Thanks!

[redwudz]

Thanks for the interesting information. Is the same problem present if just the main movie is ripped, or is that what you had done?

You are correct that determining the proper offset is difficult. I haven't found the 'best' way yet.

And welcome to our forums.

[Creeping Death]

The audio problem with the Sin City Recut DVD occurred on both the main movie on Disc 1 and the 4 episodes on Disc 2. (I didn't mention this in the OP.)

The Pixar movies actually ripped with no problems. For some reason, I had audio problems on the shorts only.

Some of the DVDs I did had multiple cells, all with different lengths. So I think some experimentation might be needed to determine which cells can be discarded. (Though I'm still a little in the dark about what the cells are...)

Thanks for the welcome. I hope this information is useful.