Captured 24A footage wildly out of sync in FCP, but fine in QT

Question

I just captured a bunch of 24A footage I shot on my Panasonic DVX100A and was dismayed to find that the clips were all wildly out of sync when I opened them in FCP--even though they are fine when I open the captured files directly in QT on my desktop. But when I play these same clips in FCP, the audio slips so steadily out of sync that on one 47 minute take, the video ended seven minutes before the audio, so the clip ends with seven minutes of sound against a black screen!
I actually found a workaround for this problem in a thread started by another poster with a similar sync problem. On that thread someone suggested that if I simply opened the underlying file as a QT movie on my desktop and then edited a second or two from the beginning, and saved it as a new Self Contained QT movie, I could import that one into FCP and it would have no sync issues. For reasons I still don't quite understand, that workaround solved the problem almost every time.
Until now, when not even that convoluted solution seems to help with this latest clip. Even after shaving the ends and saving it with a new name, the resultant QT file still imports into FCP with the same off sync problem.
Obviously, the best solution would be to figure out why clips are capturing with bad sync in the first place. For the record, I've shot and captured many, many hours of 24A footage from this camera in the past without experiencing any syn issues. As far as I can tell, the audio was shot and captured at 48.0 KHZ, just like always. (And the out of sync clip shows up as having 48.0 KHZ audio in the FCP browser.)
Since it was shot at 24A, I captured it using Advanced Pulldown removal as always. (Oddly, I notice in the browser info window that the clip shows up as 29.97 fps and not 23.98--if that's a clue to anyone.)
Thanks for your guidance on a sticky issue that has me stopped in my tracks.

Answer 1

Hello GeeFor,
I was browsing for a different audio sync issue and came across your post. It caught my attention because I believe that I've ran into the same problem before and figured out what causes it, so I thought I'd share my experience.
You said that you've noticed that FCP initially recognizes the problem clips as 29.97, even though you've captured the 24PA footage with Advanced Pulldown. I've found that if, while you are capturing 24PA footage, you allow the capture to go beyond the recorded footage and into blank tape, that FCP recognizes the entire clip as 29.97. This causes audio sync problems, and if you end up trying to do a final export, will cause video problems as well.
I've successfully duplicated this problem and the solution is to make sure to stop your capture before your 24PA footage ends and blank tape begins. One way to avoid the problem is to record black to the entire tape while on the 24PA setting prior to filming. I normally just record an extra minute or two while on location at the end of the footage.
I think your work around in Quicktime works because you are effectively removing the break in timecode at the end of the clip, therefore FCP sees a start and end timecode that matches the 24PA settings.
I hope this fixes your issue, I'd be curious to know if it does. I did a lot of trial and error to figure out what my problem/solution was and I couldn't find anything in the forums that helped with my particular issue.