Audio sync issues in FCP X

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Level 1

5 points

Audio sync issues in FCP X

Here is the scenario: The video shoot is an interview format. I recorded my audio externally using the Zoom H6. The sample rate was set at 48kHz, 24bit.

The camera used to shoot the video was a Canon 60D. It appears that it recorded its audio from the internal mic on the cam at 48kHz. The frame rate was set to 1920x1080 @ 24fps.

I bring the audio and video file into my project on FCP X and sync them to my slate. Slowly but surely the external audio starts to fall behind the video.

Project settings for FCP X are: 1920x1080 | 24fps. Audio is Stereo | 48kHz.

Please help! What am I doing wrong here?

iMac, OS X Mountain Lion (10.8.4)

Posted on Jan 18, 2014 7:08 PM

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Answer 1

Jan 20, 2014 12:24 PM in response to ApplePhan142

I'm having the same problems even shooting @ 29.97, or 60i... Never before did I have this problem.

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Answer 2

ApplePhan142 Author

Level 1

5 points

Jan 20, 2014 1:19 PM in response to ErikOlsen

Erik,

Are you using a Zoom, too? I spoke with my audio guy at Sweetwater Sound and he spoke with the tech guys in their media department about this and they all came to the same conclusion. They thinkmy Zoom malfunctioned. This is a sample rate issue. I had it set to record a sample rate of 48kHz. The actual audio files says that it is 48kHz. What really must've happend is it recorded it at 44.1kHz instead and just stamped the 48kHz on the file.

I am not yet positive if this is the root cause and I am expecting a call from the support team at Sweetwater Sound to help troubleshoot this with my Zoom. One thing to add is I brought the audio file into Logic Pro and Logic then converted it to 44.1kHz. When I then play the audio file in Logic along side the video file using either Preview or QickTime, they then stay in sync.

I will let you know what I find out!

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Answer 3

Jan 20, 2014 3:02 PM in response to ApplePhan142

Yes, Zoom H1... I set it to 44.1kHz, which might be the problem.

It's possible to use the 44.1kHz rate when shooting @ 24p and 48 kHz when shooting in 29.97...

I'll do some tests to varify my theory...

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Answer 4

Tom Wolsky

Level 10

151,010 points

Jan 20, 2014 3:05 PM in response to ErikOlsen

Try converting the audio to 48K.

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Answer 5

Jan 20, 2014 3:09 PM in response to Tom Wolsky

I thought of that too, but not sure how to do that in FCP10.1..

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Answer 6

Tom Wolsky

Level 10

151,010 points

Jan 20, 2014 3:17 PM in response to ErikOlsen

You don't do it FCP. You do in Compressor or MPEG Streamclip or done other conversion tool. You could export from FCP and reimport, but it's probably simpler to do outside the application.

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Answer 7

Jan 20, 2014 3:33 PM in response to Tom Wolsky

I just created a compound clip from the 41k audio file and chose 48k for my sample rate... wonder if that should do the trick...

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Answer 8

ApplePhan142 Author

Level 1

5 points

Jan 22, 2014 8:05 AM in response to ErikOlsen

Well, just got off the phone with tech support from Sweetwater Sound and came to the conclusion that the problem lies in FCP X. My audio file is 48 khz, just like it says. SO... What am I doing wrong in FCP X?

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Answer 9

Jan 22, 2014 10:21 AM in response to ApplePhan142

If the problem ies in FCPX, then you might not be doing anything wrong... we'll just have to wait for another update...

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Answer 10

ApplePhan142 Author

Level 1

5 points

Jan 22, 2014 10:39 AM in response to ErikOlsen

Turns out that it is a drop frame issue. I should've caught this earlier. When I shoot video on my Canon 60D, I usually use 24 fps. Well, Canon uses NTSC drop frame so it really shoots at 23.98. I had my FCP project set to 24. Once I realized this was the issue, I made a new project set to 23.98. This, in return, fixed my error.

UGH... Thankful that I can close this issue.

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Answer 11

EEagan

Level 1

0 points

Jun 13, 2014 12:00 PM in response to ApplePhan142

What I find interesting is that in FCPX when creating a new project with the option Video Properties "set based on first video clip" and then import a 23.98 video file the frame rate is 24.

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Answer 12

Tom Wolsky

Level 10

151,010 points

Jun 13, 2014 12:10 PM in response to EEagan

What version are you using? Can you upload a small piece of this software somewhere? Thanks.

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Answer 13

Jul 14, 2014 10:37 AM in response to Tom Wolsky

Hi FCPX & Apple...

I searched the internet to see if I can find this issue and came to this site. So created my account and logged in and adding my bit (apols for my name that appears...completely accidental! 😉 )

There is an issue with FCPX - ver 10.1.2...I'm convinced...(I bought a iMac 27" full spec machine in Feb 2014). Very recently I've been working on a show reel and I have imported a file (short film). I set the project to the film's settings ie.. "set based on first video clip"...(1920x1080 24p, 1080p HD), audio rate bit 1536. When I play the film in FCPX the audio "hic-cups"..."dips to silence"..."drops-out" briefly and very frequently all the way through (approx 15 mins long film)...note: audio set is at stereo 48kHz.

I also have a version of the film in 2048x1240 24p at 2k, again Stereo 48kHz...and this does the same audio "drop-out" all the way through.

So I went off trying to see what was happening. In the main story timeline...do this...

...Control-click on the picture...and select "Detach Audio" so that audio and video are separated...then...play the film/file where those audio issues occur...you'll notice that the audio still glitches i.e. still drops out frequently...

...now...

...click on the video component and press "v" to effectively "grey it out" so you do not see any video in the Viewer but your audio is still "active"...now...go back to the area where you believe the audio "glitches"/"drops-out"...and play it again.

...it plays fine...no issues!

...To prove it to yourself...as you play the film/media and with the video component highlighted...press "v" on/off to activate the video only and notice that the audio plays fine (no "drop-outs") when the video is deactivated...but the "drop-outs" are return when the video component becomes active again (press "v" again)!

The video component is affecting the audio component in FCPX! When you output to any file format, these audio glitches disappear...hence an software issue!

FCPX / Apple Please Fix! It's driving us crazy!

😉

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Answer 14

Jul 14, 2014 11:00 AM in response to hakanfromlondon

Hi FCPX & Apple...

Just to add to my text above...

The video component is affecting the audio component in FCPX! When you output to any file format, these audio glitches disappear...hence an software issue!

Note: Final Cut Pro 7 does not do this with the same films - I also have a separate laptop with FCP7 and OS X v10.7 Lion and have tried this with no problem!

Also...luckily...I have a .wav file of the audio of the whole film...when I remove the audio from the film and replace it with this .wav file...there is no problem. Again, it seems like FCPX does not like this "attachment" of HD or beyond film format video with audio...hence a software issue.

FCPX / Apple Please Fix!

😉

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Answer 15

Tom Wolsky

Level 10

151,010 points

Jul 14, 2014 12:20 PM in response to hakanfromlondon

There's a lot of information except the most important: what are the complete specs of your media, video and audio? Also where is the media located? Where did it come from? And how did it get into your computer?

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