[Arthur Vincie]

“As far as I know” – means just that. FCP says “23.98” as the timecode base for the clip video and audio, but that doesn’t mean anything, since it’s shorthand for 23.976.

I’ve played the clips in QT and the problem remains the same. However, it’s a little harder to check since there’s no way to scrub video AND audio one frame at a time in QT (you can advance/retreat by one frame but the audio doesn’t play, unless there’s a control I’m not aware of).

My clips are fairly short, but they do seem to stay exactly 2 frames off (I’ve encountered a few clips that are exactly 1 frame off, though I’m not sure what that means). If there is a drift it’s so subtle that it’s not cropping up in the 2-3 mins. average length of the clips.

The Canon E1 plugin for FCP didn’t give me any choice as to framerate, but since it was made by Canon specifically for Canon 5D footage I’m assuming (maybe a bad assumption) that they’ve thought of the framerate discrepancy.

Have checked with some other editors and my DP and they’re looking into both my footage and the problem in general. Could be a camera issue.

When sliding the audio a frame forward it syncs up fine, so I’ve proceeded with my logging in the meanwhile. Just hoping I’m not overlooking something that will bite me in the butt later on.

[Arthur Vincie]

The H.264 file suffers from the same problem (audio slate is one/two frames off from visual clapper) – when playing back in FCP. You can’t really scrub in QT frame-by-frame AND check audio, so again I’m not sure if this is an FCP issue or a footage issue. I’ve asked my DP to check his camera settings.

The audio doesn’t seem to drift from the front to the end of the clip, though if it was a really slight drift I probably wouldn’t notice it since the clips are relatively short (5 minutes is long).

[Arthur Vincie]

I appear to be having a related problem. However, I’ve used all the techniques outlined above and still have internal sync consistency issues.

The source material is clips from a feature film shot on the Canon 5D Mk2 with the latest firmware update. We used a slate with a traditional clapper to sync up to separate-source audio. HOWEVER, I’m not even at the point of syncing yet. I’m noticing this problem with the clip itself.

Format: 1920×1080 23.976fps progressive
Transcoded to: ProRes (LT)
Using: Canon plug-in (latest version) for Final Cut Pro
Software: Final Cut 7.0.3, Mac OSX 10.6.4
Hardware: 2x 2.4 GHz 8-Core, 8 Gigs of RAM, 2TB internal editing drive, 2 TB E-SATA drive (for backing up camera masters)

The FCP sequences are all running at 23.976fps. The clips (as far as I can tell) were transcoded properly at 23.976.

When playing the clip both in the Viewer AND in a 23.976 sequence, the slate is ALWAYS off by one-to-two frames. However, using plosives as a guide (dialog “p”s and “b”s), it appears as though the clips SOMETIMES drift. Plosives can be unreliable (especially if it’s a wide shot).

Please keep in mind:
I’m talking about the CAMERA AUDIO in the clip, NOT another audio source. In other words, the clip IS NOT SYNCED TO ITSELF.

The clips are short (4-5 minutes at the long end). They are consistently off (by 1-2 frames) at the top of the clip. I’ve tried adjusting the playback offset but that doesn’t seem to make any difference. The slates are generally well-done (they aren’t half out of the frame or being moved while being clapped), certainly enough to tell when they’re closed.

Any suggestions? I’d love to not have to retranscode everything. Thank you very much.

Sincerely,

Arthur Vincie
Director, “Found In Time”
https://www.foundintimefilm.com
https://www.chaoticsequence.com