progressive audio desynch when converting 25fps to 23.976fps

[HallwayOrchard]

Hi everyone,

First I'd like to thank everyone for the tons of information already posted here about audio synch issues. Each one seems very specific and over the last few months I haven't been able to find an answer for my problem. Here it is.

I have a 25 fps source having a VBR audio track (VirtualDub has detected an improper VBR blah blah...) and I want to convert it to a 23.976fps DVD. These are the steps I follow:

1) with VirtualDub-MP3-freeze I save the audio (direct stream copy) as an mp3.
2) I convert the mp3 to either CD quality or 48khz uncompressed wav. (both conversions yield same problem)
3) I convert the video from 25 fps to 23.976 fps and note the new length. I save this AVI with no sound.
4) I use CoolEdit pro 2 to stretch the uncompressed wav to the new length.
5) I load the soundless AVI into VirtualDub, use the audio>wav audio to select my new converted and stretched wav, and frameserve this to TMPEnc.
6) I author the resulting mp2/wav files with DVD-Lab and burn

What I end up with is a great looking film with awesome sounding audio which gradually gets out of synch. I have read every post on synch issues and nothing has worked.

Any help would be very much appreciated.

Thanks and keep up the awesome work!

[pijetro]

5) I load the soundless AVI into VirtualDub, use the audio>wav audio to select my new converted and stretched wav, and frameserve this to TMPEnc.

Perhaps you could Save as .AVI again, with what you've interleaved, and check the synch again, by reloading the new .AVI..

[HallwayOrchard]

I have tried saving portions of the video and it seems in synch.

I want to try to get away from having to save an entire uncompressed avi if possible, or having to recompress and lose the quality.

[ZippyP.]

After you have loaded the video and audio into Vdub and before starting the frameserver...play it from the main window in Vdub, move the slider to near the end where the sync should be worse. Is it in sync?

[pijetro]

Zipp P. is correct. That's what i was getting at also, except, that if you do the extra step of saving the newly created interleaved .AVI, then it's bulletproof...

I want to try to get away from having to save an entire uncompressed avi if possible, or having to recompress and lose the quality

If you're using the direct stream copy to interleave, then there's no case for uncompressing your .AVI. True, you've created an extra copy, but the filesize should be the same as your original .AVI..I'm assuming it's DivX or something to that nature...

Good luck!!

[HallwayOrchard]

Thanks for the tips
When I preview the film or save off a segment it appears to be in synch.

I never thought about the fact that the direct stream copy would be fine in this case. I'm used to frameserving due to problems I've had with TMPGEnc not wanting to use the saved AVI file.

I will try this stuff out and post back...

Thanks again.