Sync (sound drift) issues

[vzankovsky]

Please advise

I bounced a stereo mix of a feature (48kHz/24 bit)
When I import the track to FCP 7 timeline it drifts. No matter what I tried to do sooner or later the sound gets out of sync. I read and tried many things including Easy setup frame rate and sample rate adjustments, playing with timeline preferences, no luck.

To make sure it is not FCP7 issue I made a test. When I try to play the film with VLC (the sound is added to VLC as a separate track) audio still drifts.

I read if you export from Pro Tools with a sample rate 47952 it can fix it. And to tell you the truth it worked. But I wonder if it is the only way to fix the sync problem. It is a bit strange to release a movie with 47952 sample rate.

Any solution?

[Craig F]

a lot of this is discussed here http://duc.avid.com/showthread.php?t=212057

[vzankovsky]

Thanks a lot, will check it now.

[JFreak]

It is a bit strange to release a movie with 47952 sample rate.

Is it less strange to release it with a "48k pull-down" sample rate? It is a common thing when you do video. Your talking about frame rates there, and a DAW works in samples.

[vzankovsky]

Craig F i went through your link.
Didn't work for me.
In my case I have the original track that is created and mixed in PT, synced to a video file perfectly well, no drifting and syncing issues at all. Then bounced.

After I open absolutely the same video file let's say in VLC, add bounced audio track as a separate file, as soon as I play it the audio is already out of sync a bit and as it goes along during playback audio sometimes gets back to sync and out, in and out. It is not the case when more to the end audio gets more out of sync.

And of course the same I get with FC7. It is not just Final Cut.

BTW before 47952 pull-down worked for me, but now it gets even more out of sync

[Craig F]

it makes sense if the if FCP did it's standard move of making a 23.976 video as 24
most picture editors and VFX guys don't understand the difference, so the don't care and screw over audio