Pal, Ntsc, & DGPulldown, oh my...

[jchristl]

Hey all. I have this PAL AVI. I Encoded it to mpv using Quenc. I had a Avisynth script that framed it to 720x480. I ran DGPulldown to make it 29.976 and then authored with DVD lab.

I checked it with WinDVD and noticed a slight audio de-syncing that would creep ever so slightly off throughout the film. I checked the interlace with DVD2SVCD and it said it was non-interlaced. I doesn't look like its interlaced if I look at it (I guess).

I did noticed however that, for some reason, the GOP setting in Quenc had been set to 12. Not sure how that happened. Could that be the reason for the audio problem?

What I am doing now is to re-encode the PAL AVI using a GOP of 18, since it will eventually become an NTSC file. I believe this would be correct. Does it sound correct?

Thanks for the time,
Joe

[Guest]

No, the GOP size of 12 would not cause AV desync.

To try to isolate the problem, you need to verify the time durations of the audio and video at several points before authoring: 1) after demuxing, 2) after encoding, and 3) after applying DGPulldown. If they are the same duration just prior to authoring, then you need to investigate your authoring options.

Also be sure that you chose 25->29.97 in DGPulldown.

[jchristl]

Well, the delay is there before DGPulldown. I've read other threads regarding this, and it seems like alot of people that use DVD Lab have noticed this. That's what I authored with.

I guess I gotta learn another program... grr..

[Guest]

Well, the delay is there before DGPulldown. I don't understand this statement. I asked about the audio and video durations. If there is a difference between the durations prior to DGPulldown, you shouldn't be blaming your authoring program.

[jchristl]

Yeah I just was thinking that same thing.

Here's what confuses me though - If I stop the film and replay it at the time I can tell the audio is out if sync, then it isn't. Its like when I reload the player, at a later chapter the audio is not out of sync. But if I let it play long enough, it soon will be.

What could be causing that?

[Guest]

Make sure you rip only one angle at a time.