FCP X Audio Sync Drift

Hi guys,

I'm really sorry if this has been covered before... I just couldn't find any solutions that helped with my problem.

I have a Canon 5D iii and a Sony NEX-VG10E

I use the Sony to record the majority if the event and use the Canon to record 5 min clips of a second angle.
The problem comes in when i drop the footage into the timeline (Final Cut Pro X Version 10.0.8 ) .
I drop the Sony's footage (with audio) in first and then add the footage (video only) from the Canon above the Sony's footage.
After finding the correct place for the Canon's footage and pressing play i noticed the first few seconds are perfect but after 5 or so seconds the audio starts going out of sync with the video...

I would really appreciate if someone could be of some assistance in this matter.

Thanks
Andre

Is there audio recorded with Canon? What are the audio sample rates and the frame rates used by these cameras?

I record audio on the Canon but only for reference, when it comes to syncing manually...

The sample rates on both are 48khz

The Canon is shooting at 23.98fps
and The Sony is at 25fps

Thank you for the reply

The problem may be in the mismatched frame rates. I haven't looked into this. You might try converting one of the Canon clips to 25fps and see if that fixes it.

Would I be correct in assuming that if I make the custom settings in my new project: 25fps this will convert it automatically?

Thanks again

Isn't your project 25fps already? I meant converting a piece of the Canon media outside FCP. You can use Compressor or MPEG Streamclip.

It's set to default settings. So I guess it uses the frame rate of the first clip I use...
I will give the converting a try.

Thank you

you are correct that it is the mismatch between sample and frame rates. but this is very very easy to fix.

1) sync the audio at the beginning of clip (which you have already done)
2) choose a point towards the end of the clip where there is an easy visual to sync to. mark that spot.
3) find the corresponding spot on the audio. mark that spot.
4) select the entire audio clip and retime it, either fast or slow, does matter.
5) grab the retiming handle at the end of clip and slide in either direction until your two marks line up.

if you are working in synchronized clips, then you can just open the synched clip in timeline and do this. otherwise you can just do this in you main project timeline.

Thank you! this worked perfectly.
i have noticed if i retime the canon footage to 96% it matches the video from my sony.

What is the cause if the frames drifting out of sync?

Would it possibly have anything to do with the wright speed of my SD cards?
one is 30MBp/s and the other is 45MBp/s

thank you for the help

Nothing to do with your cards, it's simply the frame rate mismatch between the two cameras. If you can run them at the same rate (whether that's 23.98 or 25fps), you should find they stay in sync much better. They may still drift, depending on how accurate the clocks on the two cameras are.

Usually, you can get FCPX to conform clips to the timeline framerate (check the retime menu, and particularly the conform settings in the inspector, for the off-rate clip - ie. the Canon clip if you're in a 25fps timeline).

I am recording using Final Cut Pro 6 and then using Final Cut Pro X to do all of my editing. For some reason when the video is recorded with the audio the audio starts to drift, usually towards the end of the recording. I have to different cameras capturing the same thing, but only one camera starts drifting. This just started happening all of a sudden. Everything is fine in the beginning and then sometimes it starts in the middle, sometimes not until 3 minutes before the end of the video. Any suggestions of what could be happening and is there anyway to fix it in Final Cut Pro X?

Thanks so much!

~Andrea

Verify both cameras are recording audio at a 48kHz sample rate. Mis-matched sample rates is very common for causing audio drift.