MOV files seem to import at wrong speed?

I am editing a music video out of several clips that were shot by different people with different devices in various file formats, which all were recorded to sync with the same audio track. Most line up with the audio as expected, however I am having a problem specifically with .MOV files - when I sync the start of the video to the audio, it gets increasingly out of sync as the song progresses, with the video performance ending noticeably later than the recording; i.e. the speed of the entire video clip is slightly slow. Any .MOV files that I try to import into FCP have the exact same problem. All of the video clips I’m using have the same frame rate (29.97).



Has anyone else had this issue? Someone please help!?!

What are the audio sample rates of the files? Are the QuickTime files iPhone video?

"... it gets increasingly out of sync"

This is an issue with the Sample Rate of the audio that was recorded in your video clips. Video frame rate has nothing to do with it. Verify the Sample Rate for all audio in those clips are 48kHz, which is standard video sample rate. Some cameras are capable of 44.1kHz which will drift out of sync if combined with 48kHz audio.

What are the audio sample rates of the files? Are the QuickTime files iPhone video?

Yes, I believe they were all shot on iPhones. The sample rates of the out-of-sync files are 44.1 kHz whereas the others are 48 kHz.

This is an issue with the Sample Rate of the audio that was recorded in your video clips. Video frame rate has nothing to do with it. Verify the Sample Rate for all audio in those clips are 48kHz, which is standard video sample rate. Some cameras are capable of 44.1kHz which will drift out of sync if combined with 48kHz audio.

Yes the clips that are causing the problem are all 44.1 kHz. However I tried converting those video files to 48 kHz and re-importing them to FCP, yet they are still out of sync!