23.976 Audio Export To Quicktime Issue

[Jim Blokland]

Dave:

Thanks for your considered response. Yes, I have spoken to the facility doing the filmout and they confirmed that the lab will pull down/up? the audio to 24 fps to match the film print. I was just concerned that once the file was a Quicktime file, that Quicktime did not seem to support 23.976 and automatically changed the framerate/duration to 24fps.

But it sounds like Quicktime is smarter than I am, and that playing back at 24 fps will work just fine.

Thanks again for your response.

Best, JIM.

OSX.4.3
Dual 2.7 G5
3.5 GB RAM
Radeon X800 XT
Kona 2 / K-Box
Seritek 1.2 TB RAID
AVID XPRESS PRO/MOJO

[Gary Adcock]

[Dave LaRonde] “You’re running into frame rate issues.”

Sorry Dave
audio files do not have frame rates– Audio is measured length of time only.

“23.976 is just a tiny bit slower than 24.”
23.98 is the default format for 24p VIDEO especially with content from telecine.

Jim
what happened most likely is that when you outputted your file you let the computer set the timebase and it chose 29.97 for the video and audio combination, QT does a really lousy job at this type of conversion.
Send your audio house an AIFF file from Quicktime and it should be fine. That type pf file is usable by virtually all post facilities send them a separate combined file and make sure the timebase of the QT file is the same as it is in your project.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL

[Jim Blokland]

Hi Gary:

Thanks for your response. I thought the same as you did, and re-output the file making sure that the Kona 8-bit 23.98 presets were all selected. Thought I solved the problem, as when I re-imported the file, all was well. However, as soon as I changed the ‘Open With’ dialog in the ‘Get Info’ box and re-imported, the duration changed and synch was lost.

Can’t remember for sure, but I believe that was also true with the AIFF I tested. I’ll give it another go and see what happens. I’m starting to think it’s just a Quicktime oddity…

Best, JIM.

OSX.4.3
Dual 2.7 G5
3.5 GB RAM
Radeon X800 XT
Kona 2 / K-Box
Seritek 1.2 TB RAID
AVID XPRESS PRO/MOJO

[Gary Adcock]

[Dave LaRonde] “Even if that audio file is a Quicktime movie with an assigned frame rate? “

Then its not an audio file- your output is a video file with audio embedded

.[Dave LaRonde] ” I’d always thought that if it’s Quicktime WOULD assign a frame rate to a quicktime movie audio track, but that an AIFF is frameless, and that’s about the only difference between the two.”

First –that depends on what version of quicktime. But if the file has video yes QT will “ASSIGN” the frame rate that is embedded in the QT metadata. QT as a standalone player app can modify the FPS during playback to fit the speed of your machine. After a OS crash or dumping of the prefs QT will default back to working at 60i.That change in the settings is often overlooked when trying to output the content from FCP using something like QT conversion. –frame size is the other one that gets overlooked.

The title of the thread says Audio Export – IMHO I would never send an video file with audio to an audio post pro. I would send the audio as OMF or a stereo pair with a separate video reference with audio and TC. Any re-compression of the audio when making the new file could be disastrous if you should choose to wrk this way.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL

[Jim Blokland]

Okay, I may be losing my mind. Oh well. But I just exported AIFFs and re-imported them and they seem to be fine. Duration same. The only difference (and this is small) is that the T/C starts at zero, but it doesn’t matter as the files start at the 2-beep for synching purposes.

Thanks to you both for your help.

Best, JIM.

OSX.4.3
Dual 2.7 G5
3.5 GB RAM
Radeon X800 XT
Kona 2 / K-Box
Seritek 1.2 TB RAID
AVID XPRESS PRO/MOJO