Sync issues with Batch Capture

[Bob Zelin]

try this, and PLEASE reply back, to say if this worked –

Go to FCP System Settings, select the Playback Control tab,and uncheck SCRUB HIGH QUALITY –

does this fix your sync issue ?

Bob Zelin

[Mirabelle Ang]

Thanks Bob. i tried that already and it didn’t help. it seems like the only way to work around this problem is to close log and capture window, refresh device and reopen it again. Sometimes that helps, and if not, we’ll delete the fcp pref. files. it’s not ideal but that seems to help till sound goes out of sync again.

[Tim Allison]

We too have experienced some weird audio sync issues. Sometimes when you scrub along the time line too fast, audio and video will go out of sync. But if you merely wait 10-15 seconds, and then play the time line again, everything is back in sync. We can live with that.

We have experienced an intermittent problem where clips are captured out of sync. The past several times it has happened, the audio is always ahead of the video by 7 frames. If we go into the capture scratch folder and throw away the media from these shots, and then recapture them through batch recapture, most of the time, they are recaptured correctly.

This has been an impossible problem to chase down. First, it is an intermittent problem. We have not seen any consistency to this problem at all. Secondly, we just rebuilt our system. We went from a G5 to a Mac Pro. We went from Tiger to Leopard. We went from a Kona LS to an Io-HD. We went from FCP 5 to FCP 6. The only thing that has stayed constant is we are still using the same CalDigit S2VR Duo drives, but we change the eSATA host adapter cards, so even that has changed.

[Gary Adcock]

[Tim Allison] “We too have experienced some weird audio sync issues. Sometimes when you scrub along the time line too fast, audio and video will go out of sync. But if you merely wait 10-15 seconds, and then play the time line again, everything is back in sync. We can live with that. “

TURN OFF the “High Quality Audio” setting in the Prefs – you do not need audio to be sampled at anything higher than preview (low) for normal playback with video.

“We have experienced an intermittent problem where clips are captured out of sync.”

Since you do not mention machine or capture specs we can only guess- my first would be to tell you NOT to capture camera generated bars from PANASONIC Tape cameras when digitizing- they are not generated at the shooting frame rate and do cause errors when captured in this manner.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD

[Tim Allison]

Gary,

This has nothing to do with bars and tone, and nothing to do with Panasonic. We’re simply digitizing Sony BetacamSP video. We usually work at 8-bit uncompressed.

Some new info from this morning….first, we had an extra Io-HD that had yet to be installed, so we switched it out with the first one. We fired up the system, and sure enough the first three clips we batch captured were 7 frames out-of-sync. We threw away the bad media, batch captured them again, and they were fine.

We completely shut down the system, and then fired it up again. We logged in three more clips, batch captured them, and they were 7 frames out of sync.

Any idea what’s going on here? The problem seems to be limited to the first batch capture after firing up the system. Since we switched out the Io-HD, and experienced the same problem, I do NOT think this is Io-HD related.

[Mirabelle Ang]

yup. similar issues with my setup, IoHD, FCP 6.0, Leopard, MacPro (latest), HVR1500 via HD-SDI. the problem is pretty inconsistent. refreshing the device seems to help.

i think of the first capture as a way to wake the system. it never works the first time. i think it’s a Leopard and FCP 6.0 problem. when i did a test with AJA’s VTR xchange, the sync was spot on but the program does not do batch capture.