Why is my exported Audio is shorter length?

Question

Level 1

5 points

Why is my exported Audio is shorter length?

I have finished an edit and I am having to do a 6 channel audio mix. I am exporting my Full Stereo Mix from FCP as an AIFF file but for some reason when complete, the audio track is shorter in length than it should be?

I have checked and re-checked my in and out points. It tells me the duration is 22minutes.

I go to export a Quick Time connversion, select AIFF file and chose to have 2 discreet files. I have also tried just directly exporting "Audio to AIFF".

Everytime the audio from my 22 minute project exports and is only 21minute 58seconds 18frames????

Can anyone help me out here?

Posted on Feb 19, 2013 2:42 PM

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Answer 1

MRMathews Author

Level 1

5 points

Feb 19, 2013 3:26 PM in response to MRMathews

I have actually seen that it exports as 22minutes and is fine in QT but when I bring it back into FCP that is when I lose the duration...? Really need someones help desperately here!

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Answer 2

Nick Holmes

Level 7

30,018 points

Feb 19, 2013 9:53 PM in response to MRMathews

Your mix probably has audio files that use a 44.1kHz sampling rate (audio CD standard)

It's fine in QuickTime Player because it is only playing.

FCP is trying to make your audio work in a 48kHz Sequence (video production standard)

Look at the properties of your original files and make a custom Sequence to suit or use Soundtrack Pro to re-sample to 48k.Hz

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Answer 3

MRMathews Author

Level 1

5 points

Feb 20, 2013 12:39 AM in response to Nick Holmes

Hey Nick, there is no files that are 44.1khz, they are all 48khz. I did this once before and it worked absolutely fine, but for some reason now it is just not playing ball and it is putting me further and further behind!

I make the edit in FCP and then do a basic sound mix. Everything stands at 22minutes. I export the AIFF, it is 22 minutes in QT, then I bring it into FCP and it loses duration???

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Answer 4

MRMathews Author

Level 1

5 points

Feb 20, 2013 12:57 AM in response to MRMathews

I have actually just noticed something. Although, I chose to create the sequence exactly as my footage, in the "Aud Rate" section of my browser, my footgae says it is 16bit Integer where as my Sequences are 32 bit floating Point. Would this have anything to do with it, and if so how do I change it?

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Answer 5

Feb 21, 2013 5:46 AM in response to MRMathews

Make sure your fcp easy setup frame rate EXACTLY MATCHES the frame rate of your sequence. Although there is no frame rate attached to the aiff, fcp does some kind of adjustment when you import an aiff file.

This doesn't seem to happen consistently, but I have seen it happen.

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Answer 6

Studio X

Level 7

27,229 points

Feb 23, 2013 2:13 PM in response to Michael Grenadier

Michael, do you think the audio is caught in a DF/NDF problem?

x

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Answer 7

Feb 23, 2013 2:32 PM in response to Studio X

No No No No. See I'm not always wrong!

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Answer 8

Studio X

Level 7

27,229 points

Feb 23, 2013 2:50 PM in response to Michael Grenadier

Perhaps...

If it WERE a DF/NDF issue, the difference would be around 18 frames for every 10 minutes + 1.8 frames for each additional minute. 18+18+4 = 40 frames.

21:58:18 subtracted from 22:00:00 at 29.97 frames per sec = 42 frames.

Coincidence?

x

edit: Reference re: Drop Frame/ Non-Drop Frame timecode count.

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Answer 9

Nick Holmes

Level 7

30,018 points

Feb 23, 2013 3:05 PM in response to Studio X

I'm really glad that DF/NDF is something that I don't have to deal with.

25 fps supremacy!

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Answer 10

Studio X

Level 7

27,229 points

Feb 23, 2013 3:19 PM in response to Nick Holmes

Yep, this is one thing the Euros got right. Well, that ... and architecture ... and food ... and cars ... and fashion ... and .... and ... and. But other than that ... we rule!

x

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Answer 11

Nick Holmes

Level 7

30,018 points

Feb 23, 2013 4:33 PM in response to Studio X

True.

America is the best but I prefer being a filthy, European communist.

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