Async Audio after NTSC DVD Author

[The_Flash]

I've been capturing to MPEG-2 video, MP2 audio 48kHz on my PVR-250. I want to be able to transfer the MP2 audio into an AC3 file. The problem is, everytime I do this the audio goes out of sync after authoring the DVD.

I've tried processing my captured file with PVAStrumento, running the generated mp2 into wav format, and then encoding that wav with Soft Encode. I've also tried stretching the wav with Adobe Audition.

The actual captured file is totally in sync. Any ideas are welcome, I'll try anything at this point. I'm authoring with TMPG DVD Author.

[jggimi]

This sat in the Capture forum for a couple of days with no responses. I don't have a definitive answer, just a guess... in that the audio sampling rate may need to be set to 48khz. That's the standard for LPCM DVD, and it's seems to be the sampling rate of AC3 on commercial DVDs, but I don't know if 48 is required for DVD or not. I do know that sometimes downsampling from 48 to a lower rate can cause sync trouble with MPEG4/AVI.

I'm moving this to the DVD Authoring forum, where you're more likely to get a definitive answer.

[The_Flash]

Thanks for your response (and the move). Unfortunately I am capturing at 48kHz already, and I'm maintaining that when encoding to AC3.

When I demux the .mpa from the video with DVD2AVI it reports no delay, 0ms. I noticed Rejig says there is a -66ms delay, so I have no idea.

I fooled with AC3 Delay Corrector a little today with mixed results. Basically, when I get the audio aligned near the beginning it is then off towards the end and vice versa.

It's really frustrating because the original file is perfectly in sync the whole way through. Even when I just demux the mpa and m2v and then remux those the audio is off. Obviously data is being lost when demuxing.

It's unfortunate that the audio must be converted to AC3. If this disc were just for my DVD player I would be alright with MPEG audio.