The syncing nightmare - need help!

B

bogatyr

Active member
Hi everybody, i'm working on a film that's been shot 24fps and converted into an NTSC DVD. The DVD has been converted into a NTSC quicktime movie and now i need to sync it with the sound recorded at 25fps. I'm working in an NTSC timeline. Tried 4% slow and speed up the sound - didn't work. Any ideas?
Thanks for your suggestions
 
Sound isn't recorded at an fps. Sound is sound. It's recorded at a sampling rate of 44,100 or 48,000 Hertz, but the frame rate of the video is only relevant to the video, not the sound.

If your video is playing back at the speed you shot it at, and your sound is being played back at the sampling rate it was recorded at, then it'll be in sync.

Was your film shot at 24.0 fps and mastered to DVD at 23.976? If so, it's your video that's out of sync and you'll need to correct the audio to match. Or is it the quicktime movie that's out of sync?

Here's the thing -- find out how long the running time of the DVD is. Compare that to the running time of the quicktime movie. And compare that to the running time of your audio. Somewhere there you'll discover the discrepancy and the fix should present itself.
 
The audio itself is not actually frame-based at all, ever. It's sample rate-based, at least where playing time considerations are concerned. So if the audio ran in sync with the picture at 24fps, and the picture was properly pulled up to 29.97 (in other words, there is no overall speed or running time difference in it), then the original audio should sync up fine once it's simply placed in the timeline and left at its original sample rate (usually 48KHz with video).

"Frame rates" in audio are only for reference purposes within an application. 48KHz audio is 48KHz audio, and will always play the same way intrinsically clock time-wise, apart from whatever a particular app may regard it as...
 
Barry_Green said:
Sound isn't recorded at an fps. Sound is sound. It's recorded at a sampling rate of 44,100 or 48,000 Hertz, but the frame rate of the video is only relevant to the video, not the sound.

If your video is playing back at the speed you shot it at, and your sound is being played back at the sampling rate it was recorded at, then it'll be in sync.

Was your film shot at 24.0 fps and mastered to DVD at 23.976? If so, it's your video that's out of sync and you'll need to correct the audio to match. Or is it the quicktime movie that's out of sync?

Here's the thing -- find out how long the running time of the DVD is. Compare that to the running time of the quicktime movie. And compare that to the running time of your audio. Somewhere there you'll discover the discrepancy and the fix should present itself.
Click to expand...

Ya beat me to it by 3 minutes!:thumbsup:
 
Thanks guys, I figured out that something went wrong during the conversion of VOB files into MOV. Mpeg streamclip completely messed up the timecode. However, if I drop the VOB files, which are 25fps, on the timeline the sync is fine. The question now is what sequence settings to use so that i don't have to render the VOB? I looked up item properties, it only gives me dimensions 640by480 but no info on compression type and pixel aspect ratio. Any ideas?
thanks a bunch
 
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