Topic: Audio sync to Video

[mmadd29]

I'm doing my first crack at video.  I'm using Adobe Premiere 6.5, not that I think it makes a difference which software as this is generic question.

I have synced my audio to the video.  The show is about 40min, at about 35 minutes is goes about a sec or so out of sync. 

How do I go about syncing that portion without changing the synced part.  I'm looking for the terms/process. 

Another important piece is that I screwed up and recorded in 44.1KHz, 16 bit.  In the future I will record in 48KHz.

Thanks for any tips and pointers.

[stantheman1976]

Does it go out of sync rather suddenly at that point or is it a gradual drift?  If it's sudden it could be from dropped frames in the video.  Did you capture with a program that tells you while capturing if frames are dropped?  If it's a gradual drift it will just be a matter of finding the amount of drift and stretching/shrinking the new audio to make up for it.  I use Vegas and you can do it visually.  Also, recording at 48KHz won't necessarily make a difference.  If the clocks in your two devices are not matched it can still drift.

[mmadd29]

Does it go out of sync rather suddenly at that point or is it a gradual drift?  If it's sudden it could be from dropped frames in the video.  Did you capture with a program that tells you while capturing if frames are dropped?  If it's a gradual drift it will just be a matter of finding the amount of drift and stretching/shrinking the new audio to make up for it.  I use Vegas and you can do it visually.  Also, recording at 48KHz won't necessarily make a difference.  If the clocks in your two devices are not matched it can still drift.

I think it is a gradual drift.  I'd have to watch closer.  I used WinDV and it had 0 dropped frames. 

I believe your correct and that's it's clock speed, that was my first guess.

My next question is how do you stretch and sync without screwing up the sync parts?

Wasn't there a calculation you can use using both files?

[stantheman1976]

There is a way to calculate but I don't know how to get the percentage.  I've never used Premiere so I don't know if there's a way to do it.  In Vegas I just get the beginning synced and stretch/shrink the end of the new track to match the end of the original. 

If WinDV recported 0 dropped frames you have no need to worry about that.

[mmadd29]

There is a way to calculate but I don't know how to get the percentage.  I've never used Premiere so I don't know if there's a way to do it.  In Vegas I just get the beginning synced and stretch/shrink the end of the new track to match the end of the original. 

If WinDV recported 0 dropped frames you have no need to worry about that.

Check out this post.....I think this is the answers to my issues.....

http://taperssection.com/index.php/topic,97244.0.html