FORUMS: list search recent posts

Audio "shrinks" on QT output and DVD input

COW Forums : Apple Final Cut Pro Legacy

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Larry Elin
Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 2:27:09 pm

I have a FC movie file that is 48:44:25 (M/S/F) in length. The video is 1940X1080. The audio file is in .aif format, 48/16. In FC, the audio and video sync perfectly. When I output a self-contained quicktime movie, using "current settings", the audio begins in sync but gradually lags behind the video until it is way off by the end -- about 3 seconds. If I output the audio file alone from FC as a quicktime file, it is the correct length! If I send the FC movie (video and audio) to compressor, and use the compressor settings designed for a 90 minute DVD, I wind up with a video file (m2v) and a sound file (ac3) both the correct length. At least, they are if I open the sound file in iTunes, or bring both the sound file and the video file back into FC and put them into a timeline to see what length that program thinks they are. If I then import those two files (m2v and ac3) into DVD PRO, in the Assets panel, the video is the proper 48:44:25, but DVD PRO thinks the audio is 44:41:27. DVD PRO also thinks that the original .aif file, and the audio-only quicktime file, are 44:41:27 -- 3 second short. If I burn a DVD, the audio lags behind the audio just like it did when I output a QT directly from FC.


So, the problem is, I have three audio files (aif, ac3, and .mov) that are the correct length in Final Cut, iTunes, Compressor, and Quicktime, but they are all 3 seconds shorter when imported as assets into DVD PRO. The sound file is also 3 seconds too short when it is output as part of a self-contained QT movie from final cut.

Any ideas out there except that the whole thing seems haunted?


Return to posts index

Chris Tompkins
Re: Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 2:47:39 pm

Well First off:

The video is 1940X1080 I hope you meant 1920.

If you play a Self Contained HD file 48m in length off the desktop,...you could have sync issues just from a threw-put drive speed issue.


Export Current Settings. Make sure there are no in/out markers on the sequence.
Drop that file into compressor.
Create the DVD mpeg and ac3 file.
Bring them into DVDSP.
They should match.

Chris Tompkins
Video Atlanta LLC


Return to posts index

Larry Elin
Re: Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 3:12:48 pm

Mistyped on the resolution. Playback of QT is NOT the problem. Already tried what you suggest and that is when the problem first popped up. I, too, thought that the playback of the HD QT movie was just sluggish, and everything would be OK after putting the QT into compressor. But no, the audio file that popped out of compressor from the self-contained QT was, in fact, shorter than the video by 3 seconds. I went back into FC and checked that all the settings were what they had been for months -- because of all of this worked fine up until a couple weeks ago. Nothing different.


Return to posts index


Dave LaRonde
Re: Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 3:46:02 pm

The difference between audio and video duration would be just about right for a drop-frame / non-drop-frame mismatch: at the end of an hour, it would be 3 seconds and 18 frames.

Is there any point where drop and non-drop time codes could have been mixed?

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


Return to posts index

John Pale
Re: Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 3:51:51 pm

DVD SP is showing your audio in Non drop frame and your video in drop. You can change this in DVDSP, but I usually do not bother.


Return to posts index

Larry Elin
Re: Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 4:27:16 pm

I followed this advice, as well as something else I had read about using SunflowerBed to overcome some kind of driver issue. As soon as I changed the preference in DVDSP to drop frame, the audio times in the assets panel switched to the correct ones, and sync was restored in the simulator. I'm burning a DVD now. I am still having difficulties outputting a QT directly from FCP and getting a movie that syncs. But, I can breathe easier thanks to al of you!


Return to posts index


John Pale
Re: Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 5:43:51 pm

The choice of drop/non drop should not normally affect sync in DVDSP ... But I am glad it's working for you now.


Return to posts index

Larry Elin
Re: Audio "shrinks" on QT output and DVD input
on May 31, 2011 at 5:58:44 pm

Hi Dave. I will check that once again. It is a big project with many video clips, in sequences, but the audio file itself is just one big aif . The confusing part is that I can output an audio file that is correct by using Compressor, or by exporting a QT consisting only of the audio. But when I export a QT of both audio and video, using "current settings", the length of the whole QT is wrong, and the audio is shorter...the video lags behind. Thanks for your help.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2018 CreativeCOW.net All Rights Reserved
[TOP]