Audio Drifting Out of Synch on Capture

[Thaxter Clavemarlton]

“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.

[Joshua Ferg]

Thax

Thanks so much for the response. Great info.

I’m starting recapture now.

Best,
Josh

[Kevin Monahan]

Basic ROT:
Long clips and slow drives are the recipe for synch problems on capture.

Kevin Monahan
Take My FCP Master’s Seminar!
fcpworld.com

[Brent Streeper]

What if sync issues are occurring in short clips with a fast drive?

We’re capturing 23.98 DVCPro HD onto a Huge MediaVault. The Huge drive is RAID 3 and plugs into the Dual 2.5 G5 through an ATTO dual channel 4Gbit Fibre Channel card. None of the clips are longer than 2 minutes, but every now and then we find a clip with the audio about 4 frames off. When we recapture the clip, the sync is good. Obviously something is happening in the capture process that is causing the audio lag, but why is it only happening intermittently? Also, the DVDPro HD footage is only 11 MB/s, so the system should easily be able to handle the data flow.

[Dave Mac]

Ah, a Final Cut Pro solution (w/help from QuickTime)…

Create a new bin in FCP. Drag and drop your 44.1 kHZ files into it (or import them via File menu).

Select only the new bin with the audio files inside and choose File->Batch Export.

In the Export Queue window, make sure only the files you’d like to convert are listed. Click the “Settings…” button and go through the options (change sample rate to 48 kHz).

When done with the settings, click “Export.” That’s it.

Method courtesy of the Apple Pro Training Series book on Final Cut Pro 5, by Diana Weynand.

[Dave Mac]

Sorry about my previous post… I somehow responded to the wrong post. Oops.