AC3 sync and interleave questions

[Brian_92gsr]

I've been encoding The Next Generation season box sets and I'm having some sync problems with Season 1. I did season 3 and 4 the same way and everything was perfect. I've been ripping with DVD Decrypter and having it demux the AC3 file. I've been encoding with vidomi using xvid. AC3 was muxed in with AVI-MUX, using the default settings, which are 500ms preload, and 75ms interleave. Audio was in sync on seasons 3 and 4, but I can't get it right on season 1. I've tried different interleave and preload settings using both avimux and nandub. Does interleave and preload even play a role in this problem? I've been setting the delay to what DVD Decrypter named the file. Any ideas on what I should do next?

[Brian_92gsr]

One other comment, it seems to be in sync at the beginning, and it gets out of sync towards the end. What would the most likely cause for this be?

[DJ Bobo]

I never used that avi-mux thing, but using NanDub, I always use 96ms for both interleaving and preload, and the sound is always in synch, no matter what bitrate & no matter how many channels.

[Brian_92gsr]

I just tried 96/96 in nandub. I almost thought it was perfect, but it still doesn't seem quite right. When someone is talking and you have a close-up of their face it just doesn't look natural. It's just off a little bit.

[DJ Bobo]

May be you forgot to enter the delay?!

[Brian_92gsr]

I changed the AC3 filters so they didn't use SPDIF, instead having them downmix it to stereo. Everything is perfectly in sync, although the volume is very low. So it seems like the audio is in sync, it just isn't playing back correctly in AC3. I've tried bsplayer and zoomplayer, and I've messed around with the settings, still no luck.

[Brian_92gsr]

I tried ripping and enocoding the entire thing over again to make sure I didn't miss anything. Still out of sync only when using SPDIF output. If I let the AC3 filter downmix it on the computer and output a stereo signal it is perfectly in syc. I've tried about a dozen interleave settings - would interleave even cause it to be out of sync?

[DJ Bobo]

I don't know, but I think, I've read somewhere that not interleaving at all (disable the whole thing) is suited for SPDIF output. Try it out.