Audio / Video sync hell – losing my mind!

[Jerry Hofmann]

Be running FCP 5.0.4, QuickTime 7.1.3, and the latest drivers for that Kona 2 card… might fix your problems…

Jerry

Apple Certified Trainer

Author: “Jerry Hofmann on Final Cut Pro 4” Click here

Dual 2 gig G5, AJA Kona SD, AJA Kona 2, Huge Systems Array UL3D

[Paul Huppe]

Thanks for the reply, Jerry.

I’m already all up to date on the drivers and versions.

Is it possible that there’s an issue with transfer speed or something? My media’s on a HUGE Systems 2.5Tb tower connected by fiber channel.

Audio post is telling that there’s no consistency on the offset: at one point it’s off by 2 frames; less than a minute later it’s off by 1 frame, and on it goes.

Has anyone seen this problem?

Thanks
Paul

[Walter Biscardi]

[Paul] “Audio post is telling that there’s no consistency on the offset: at one point it’s off by 2 frames; less than a minute later it’s off by 1 frame, and on it goes.”

Sounds like a mismatch in Audio and Video frame rates. Like if you had 29.97 fps frame rate for video and 25fps frame rate for audio.

We just ran into that here with a 1080i/50 project where I had FCP set in 8bit NTSC mode for a different project. When I imported the audio in for the 1080i/50 project, FCP set the audio for NTSC playback. All the audio went out of syne within the first 20 seconds.

I had to trash all the audio, switch FCP back to 1080i/50 Easy Setup and re-import the audio. Then all was fine.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Paul Huppe]

Thanks Walter,

I guess the difference here is that occasionally when I view the timelines, the sync is perfect. There’s no consistency in the sync offset.

I’ll try calling HUGE and see if they have any ideas. Anyone else?

Cheers
Paul

[Jerry Hofmann]

I doubt seriously if it’s Huge’s problem… If it is somehow realated to the array, a mixdown might make a difference. I’d be talking to AJA though. It’s more likely there…

Gotta say though, the sync problem isn’t something I ever encounter using much the same setup you’re using…

Jerry

[Walter Biscardi]

[Paul] “I guess the difference here is that occasionally when I view the timelines, the sync is perfect. There’s no consistency in the sync offset.”

Are you watching this on a plasma screen by any chance? There can be an offset on plasma screens that will drift from 1 – 4 frames depending on what type of material is being fed to it. Our plasma requires a 2 frame offset for SD. 4 Frame offset for DVCPro HD 1080i/50. 0 offset for 720p HD.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Paul Huppe]

I’ve a 17″ HD/SD CRT reference monitor. I’ve also got a crappy little CRT hooked up to the end of my DVD recorders for monitoring and a 23″ Cinema Display. The sync is pretty consistent from one to the other, give or take a frame.

My monitor offset is set to 0, and I’ve never seen a problem with this before on this system.

Cheers,
Paul

[Chris R]

I have recently had a similar problem when on FCP, running off an xSan raid, with an SD 8bit Uncompressed sequence. The sync would sometimes be fine and sometimes not, depending on what the system felt like doing. The same clip could be in sync one time and not another. I concluded that the system couldn’t keep up, but couldn’t be sure whether it was the raid or the card or the Operating System or FCP that was the problem.

To investigate whether it is due to the raid, I’d suggest running a test which I didn’t have chance to do: Try playing out when no-one else is connected to the raid. Also be sure to disconnect all other network cables/access (internet or non-media networks). A colleague and I have a (completely untested) theory that excess network traffic slows down the effective speed of the San (and not because of media throughput limits). (Theory is: Although the media throughput capacity might be plenty high enough, if the metadata traffic that oversees the media data flow isn’t getting processed fact enough, then the media data flow will get delayed.)

However, what is bizarre is you seem to be saying that if you export a quicktime and play it on someone else’s (high spec) mac/pc, then it is still out of sync? And to confirm, to create the quicktimes you are exporting? – you aren’t playing out through the Kona to a hardware encoder? And when you play back the quicktimes on another computer, it is playing them either off a local drive or a different harddrive/raid that is NOT the HUGE raid you are using? If both those assumptions are correct, then I’m stumped as to what’s causing the trouble. It suggests it’s unlikely to be an issue of either media drive speed or the Kona card’s processing speed. Can only guess that there’s some sort of file corruption going on somewhere??? Or that FCP is being exceedingly retarded – but no idea why.

Just to confirm, you say it was filmed on HD – you mean eg. HD Cam or DVCPro HD cf. HDV? (HDV seems to have all sorts of fun issues due to it’s interframe compression that might explain the problem.)

[Ian Liuzzi-fedun]

I have this exact same problem running the latest MacPro on an Xsan with DV FOOTAGE!!!! What resolved it for you?