23.98 to 29.97 sync problem

[Jeremy Garchow]

[Greg Nosaty] ” My point is if they know there is a one frame delay then why don’t they write it into the drivers code and save me the hassles. anyway… “

I don’t thnk it’s that easy. Withn a 1 frame delay, it is consistent and you can account for it very easily.

[Greg Nosaty] “Problem 2 is that I believed that FCP 6 was an “open timeline” and didn’t realize that it meant about the same as “real time effects””

Yeah, the open timeline really should refer to codecs and not frame rates. Working with multiple frame rates rewuires some extra user work. This would be true of any NLE I would imagine.

[Greg Nosaty] “One of them requires a seamless 51:37;00 the other a 01:00:00;00 with bumper and commercial blacks. So everything has to match wall clock in 29.97 DF. “

OK. So in this case, I’d edit 23.98 and confrom everything to 23.98 and then figure out your timing via a tc calculator ( to make up the difference betwween 23.98 NDF and 29.97 DF). THe one from netmedia seems to do very well and it’s extremely cheap.

[Greg Nosaty] “The wild card was the Protools mix because everything that came from FCP worked was in sync. “

Good sleuthing. What’d the sound mixer have to say?

[Greg Nosaty] “But I’m still not clear how the original 23.98 audio can be laid back to a picture that has been pulled down to 29.97 DF if there is no pulldown added to the audio. “

As Aaron touched on, in audio, 23.98 and 29.97 are basically the same. Pulldown or pullup gets added when you are recording for even frame rates (such as 24.0). Since you are in a 23.98 or 29.97 environment, at that point one second of audio is one second of audio so there’s no reason to add pulldown or pullup as the audio will stay in sync.

Jeremy

[Greg Nosaty]

Actually I thought the delay in the Kona processing only happened when I ask it to to an up or down convert. You mean that it is always there and I should offset audio for all outputs?

What the mixer said was something went wrong either with the OMF or in his PT session. I’ve heard many audio post guys complain about FCP’s OMF capabilities but in this case I think the biggest part of the sync issue happened manually in ProTools.

“As Aaron touched on, in audio, 23.98 and 29.97 are basically the same” that’s what I thought. The only time my mixers have had to jump through hoops is when I’ve done co-productions with the UK and we have to make NTSC and PAL masters.

cheers,
Greg Nosaty

Cinemontage Productions Inc

[Jeremy Garchow]

[Greg Nosaty] “Actually I thought the delay in the Kona processing only happened when I ask it to to an up or down convert. You mean that it is always there and I should offset audio for all outputs? “

No, just on conversions.[Greg Nosaty] “What the mixer said was something went wrong either with the OMF or in his PT session. I’ve heard many audio post guys complain about FCP’s OMF capabilities but in this case I think the biggest part of the sync issue happened manually in ProTools. “

FWIW I have sent coutless OMFs from FCP @ 23.98 and have never ever had a problem. If you have some clips that are off by a frame and some off by 4 frames, there’s something else going on if you are certain your clips are in sync in your FCP timeline.

Jeremy

[Greg Nosaty]

Thanks for your help and advice Jeremy.

cheers,
Greg Nosaty

Cinemontage Productions Inc

[Jeremy Garchow]

No worries, glad to help.

Jeremy

[Doug Beal]

As soon as you hit tape in DVCProHD you’re at 59.94. It can’t record 23.98 without a varicam TC generator setting the flags. You also have no VITC in this format which will choke a DaVinci session, need to dub to hdcam.

Doug Beal
Editor / Engineer
Rock Creative Images
Nashville TN

[Chi-ho Lee]

“Chi-Ho Lee] “What if he had archival & stock at 29.97?”
[Jeremy Garchow]
Whenever I face this problem, I confrom the 29.97 sources to 23.98 via a variety of methods.

What have you found to be the cheapest and acceptable quality?

[Chi-Ho Lee] “Rendering the 23.98 clips inside the 29.97 seq should add proper pulldown to his clips. ”
[Jeremy Garchow]
It should, but it doens’t. It adds 2224, instead of proper 3:2. and when working in a 720p timeline, there’s no 3:2 pulldown interlaced pulldown to be had due to the progressive timeline.
“

I’m not sure about that. I don’t have the proper gear in front of me to test the pulldown. If it is indeed 2224, then it had changed because I remember testing it back in v5 and I was getting a 2:3 pulldown then.