image 25fr + sound 24fr = unsolvable problem? at
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Old May 25th, 2005, 02:54 PM   #1
Join Date: May 2005
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image 25fr + sound 24fr = unsolvable problem?

ok, here's the story. a movie shot on dvcpro50. the sound kept on dat. it seems that the sound guy has captured sound on 24fr (i get an indication 24fr on my dat machine when i play back the material). i loaded a long scene (about 3 mins) on avid, then synchronized audio+video. everything seems to be ok. i mean, that even at the end of the scene, the synchronization seems to be frame accurate.

according to the way i see it, this is not possible, since sound captured on 24fr cannot be synchronized with video kept on 25fr. as the clip would progress sound come earlier than the image.

can it be that avid captures the 24fr sound on 25fr, since this is the setting on the project i'm working on?

to put it in another way: who's the idiot? me or the sound guy? :-)

any help would be very appreciated...
Nikos Vavouris is offline   Reply With Quote
Old May 25th, 2005, 04:29 PM   #2
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Location: Toronto, Canada
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Sound is recorded as samples per second (typically 48k samples or 44.1k samples per second), and not as frames per second. Generally when you import sound into an editing program, it'll stay 48k samples/second or 44.1k samples/second. It'll stay in sync.

The timecode however uses different formats... and that is where you may run into problems.

I think this is right. But I may be confused here.
Glenn Chan is offline   Reply With Quote
Old May 26th, 2005, 01:52 PM   #3
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Join Date: Jan 2002
Location: Issaquah, WA
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3 minutes of video and 3 minutes of sound should sync up, no problem.

However, if you are resolving to FILM, the audio (25fps) would be referenced sproket holes (24fps) and you would see some slip.

That being said, I'm curious ... when you edit on a video frame, does the audio glitch at all? Though technically "in sync" I wonder if the different frame rates cause any anomalies?

Matt Ockenfels

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