[ryarber]

After editing a movie recorded from TV, the audio track somehow got shifted to the right. How do I fix this so the video and audio are synchronized again? Thanks.

[Krusty]

Originally posted by ryarber:
After editing a movie recorded from TV, the audio track somehow got shifted to the right. How do I fix this so the video and audio are synchronized again? Thanks.

How "shifted to the right" is it ? Do you mean it is off by a second or two or is the file Video (with silence) followed by the audio track (with no video). Either answer will take a lot of writing .. so it'd help to know which problem you are talking about.

Also, do you have Quicktime Pro ?? You might need it to start manipulating tracks.

[ryarber]

Originally posted by Krusty:
How "shifted to the right" is it ? Do you mean it is off by a second or two or is the file Video (with silence) followed by the audio track (with no video). Either answer will take a lot of writing .. so it'd help to know which problem you are talking about.

Also, do you have Quicktime Pro ?? You might need it to start manipulating tracks.

It is shifted to the right about 4 seconds. I do have QT pro.

[Krusty]

OK, is it ~4 seconds off the whole time or does it get progressively more "off' ? Do you have, say. 4 seconds of "lead time" with the video before the audio starts ? ... or does it start correctly but then finish off-track?

Assuming the latter, you will have to do the following:
Open the movie.
Edit-->Extract Tracks (choose Audio, it will open in a new player)
Edit-->Extract Tracks (choose Video, it will open in a new player)
Select the ENTIRE audio file (by moving the selection markers to the beginning and end of the audio track).
Select "Copy" to get the whole audio track.
Switch over the the Video that you extracted.
Select Edit-->Add Scaled. This will force the audio track to "fit" the exact length of the video track (even if the two tracks differ in length slightly -- it will slightly speed up or slow down the audio the match the length of the video).
Done.

IF the former is the case (meaning you have some video that starts before the audio, you may end up losing the 1st 4 seconds of the video. You'll have to cut the 1st 4 seconds of video out of the clip. Then you will follow the same steps above (adding scaled audio to the video track).

Hope this helps... let us know how it goes.

*Note: once you've extracted the separated audio and video tracks, compare their length. If they are not the same, you will probably have to trim the extra length out of whichever one is longer so that it matches the other in length.

[Uncle Skeleton]

http://www.applesolutions.com/bantha/Sync.html

I wrote this program one day to make re-sync-ing videos easier. If you have any problems using it please let me know and maybe I can fix them (or it's open source if you want to take a swing at it yourself). It's much easier than trial-and-error with QT Pro, at any rate.

P.S. Never EVER scale the audio track (which is what happens when you choose Add Scaled when the audio is in the pasteboard). The many reasons for this include but are not limited to: it often causes QT to drift out of sync on playback only, re-sync-ing when you pause/resume (if you think about it, this problem in a movie is impossible to ever fix). It causes the audio to no longer be one of the sample frequencies supported by your sound card, forcing your cpu to work surprisingly hard to resample at playback time to send data to the sound card. It changes the pitch of the sound track to something it's not supposed to be (Small differences in pitch are far more detectable to humans than small differences in framerate or video speed).