Quicktime Export Out of Sync

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Quicktime Export Out of Sync

I have a 2 minute video that was shot on a Canon T2i, with sound from a Zoom H4n. I had no issues syncing them up in FCP 7, and everything plays fine there.

However, when I export and open the video in Quicktime, it is ever so slightly out of sync (not a drift).

I've tried Quicktime self-contained and then Compressor, Quicktime Conversion, and straight to Compressor from FCP. They all have the same result. But when I bring any of those files back into FCP, they play fine.

My sequence is 1920 x 1080 Pro Res 24p with 48 khz audio.

Any thoughts? I've tried doing the settings as current, or also specifying them to match the Pro Res sequence.

Please help!! Thanks!

Macbook Pro, Mac OS X (10.5.2)

Posted on Jul 28, 2012 6:56 AM

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Answer 1

Jul 28, 2012 7:25 AM in response to ekgotmilk

How are you monitoring in fcp? It could be that the signal path for the audio does not match the video so when you're monitoring in fcp they seem in synch. Go to the view menu and make sure that audio and video playback are thru the same device.

Also, what are the settings for source clips? The video (which I assume has reference audio) and the audio files should both be 48k 16bit. If they are not, convert them to this before bringing them into fcp.

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Answer 2

ekgotmilk Author

Level 1

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Jul 28, 2012 7:37 AM in response to Michael Grenadier

Hi Michael,

Thanks for your response. Playback is through the same device - I initially was also using an external monitor and speakers, but tried turning those off and just going through the laptop. Same thing either way.

They're both 48/16.

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Answer 3

Jul 28, 2012 7:48 AM in response to ekgotmilk

First thing i'd try is resetting your fcp preferences.

https://discussions.apple.com/docs/DOC-2491

Try this. Duplicate your sequence and add one frame of beep and bars at the first frame and at 10 second increments thru the entire timeline. Export and see if you can see exactly how much it's out of synch in quicktime player and if that offset remains constant.

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Answer 4

ekgotmilk Author

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Jul 28, 2012 8:43 AM in response to Michael Grenadier

Tried trashing the prefs.

I added the bars and tone and they seem to be in sync (from what I can tell in QT; definitely so in FCP), which is really driving me crazy! Is it possible for the audio to be off by less than a frame? The video definitely still looks off to me.

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Answer 5

Jul 28, 2012 8:55 AM in response to ekgotmilk

OF course audio can be off by less than a frame. I'm not on my system now but search the fcp manual for subframe audio. If you can't find anything post back

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Answer 6

ekgotmilk Author

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Jul 28, 2012 9:26 AM in response to Michael Grenadier

Hey Michael,

Read a little about subframe audio, but if the sync looks okay in FCP, would manipulating the subframe help?

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Answer 7

Jim Cookman

Level 7

23,435 points

Jul 28, 2012 9:37 AM in response to ekgotmilk

You don't say WHAT your export is, but if it happens to be a wmv, they're ALWAYS a bit spongy in QT. They work fine on a pc though.

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Answer 8

ekgotmilk Author

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Jul 28, 2012 9:43 AM in response to Jim Cookman

Hey Jim -

Not a wmv. I've tried an uncompressed mov and an h.264 through quicktime conversion.

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Answer 9

Jul 28, 2012 11:21 AM in response to ekgotmilk

probably not. Honestly, what are you looking at and listening to that requires such precise synch. And how are you judging it? Wouldn't surprise me if quicktime player plays a little fast and loose with synching audio and video. Have you tried it on other machines? Wonder if it could be a drive issue. Maybe try the quicktime on a faster drive. And if you can't really tell if the 1 frame of bars and tone is exactly in synch in quicktime player, how can you tell with your actual material?

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Answer 10

ekgotmilk Author

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Jul 28, 2012 12:04 PM in response to Michael Grenadier

Ah I think I'm starting to sound crazy! I tried a few different things and re-uploaded to Vimeo (that's our final destination), and I just can't even tell anymore. Sometimes it's looked pretty out of sync on Vimeo and others only slightly.

I'm not at my usual setup so my only internet is on a separate machine from where I'm working. So I can only test the final Vimeo on one machine.

Honestly, I'd love a second opinion as to whether it looks out of sync or not. I'd rather not post the link publicly yet, but if you don't mind, could I send it to you? (My email address is in my profile). I've been staring at this for so long that I can't tell anymore.

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Answer 11

Jul 28, 2012 12:18 PM in response to ekgotmilk

unfortunately, your email address doesn't show up when I look at your profile. My email's in my profile also, but take a look, I don't think you'll see it. Thanks Apple.

Anyway, my email is mgrenadier@gmail.com

Not sure if you can actually judge it with any accuracy on a web page. There's all sorts of buffering happening which I suspect renders the whole issue moot.

But send away and I'll take a look. We've got pretty good internet at my office (fios).

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