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Audio Drift on 20-30min captures
I have a audio drift that progressively gets worse when capturing 20-30 min clips! I am capturing at 48k 16 bit, which is what my Canon XL2 recorded on. The only idea I can think is causing this is that my scratch disks are set to an external hard drive, Western Digital MyBook with 500 gigs, but I am using a USB cable, would that be the problem?? Would that gradually slow down the audio?
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3 Replies
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The infamous “Canon Drift.”
“Sync-slippage” can happen during some longer captures.
Tapes recorded on certain camcorders from Canon have been somewhat more problematic but it also can happen with other brands of cameras as well.
To reduce the problem on capture, break your captures into sections no longer than about 10 minutes each.
You can then “reconstruct” the full tape’s recording (or any longer takes) quickly if you need to.
Mark (and log) your first clip to End (Out-point) about 10 minutes or less from its In-point.
Continue to mark (and log) your clips this way throughout the rest of the tape.
Just make sure the In-points of the subsequent clips are EXACTLY ONE FRAME LATER than the Out-points of the previous clips.You can do all this while actually scanning the tape(s) or just by inputting arbitrary TC numbers, logging them… then use Batch Capture to bring in all of your clips.
Its very easy to then “reconstruct” the shorter clips back to any “continuous” length you want on the timeline by just “clicking” them on in order.
EVEN FASTER… select ALL successive clips at once in the browser (with the browser column-order set to “Media Start” highlight all clips) and drop them, all at once, on the timeline… they’ll all pop up in continuous order.Also read this link:
https://docs.info.apple.com/article.html?artnum=58640
It contains more “sync-loss” info. -
is it an inconsistent thing? I have captured long clips before and it does do it. Also, if I digitized the tapes with a camera other than my canon, will it still do that same thing? Because the audio is fine on the tapes…
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USB is not reliable for video capture. Even though its speed is comparable to firewire, USB is subject to interrupts which can cause problems for time sensitive applications such as video capture.
You might get lucky and have no problems, but generally you are better off using firewire to your hard drive if it is available.
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