Audio Sync Delay

[John Fishback]

Is the frame rate true 24fps or is it 23.987?

John

MacPro 8-core 2.8GHz 8 GB RAM OS 10.5.8 QT7.6.4 Kona 3 Dual Cinema 23 ATI Radeon HD 3870, 24″ TV-Logic Monitor, ATTO ExpressSAS R380 RAID Adapter, PDE enclosure with 8-drive 6TB RAID 5
FCS 3 (FCP 7.0.2, Motion 4.0.2, Comp 3.5.2, DVDSP 4.2.2, Color 1.5.2)

Pro Tools HD w SYNC IO & 192 Digital I/O, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec Monitors, PrimaLT ISDN

[Chuska Esteban]

Hello John:

Thank you so much, for answering.

Where I can check that the frame rate true 24fps or is it 23.987?
In the sequence settings or in the Browser, I see that is set to 24 fps.

I have read that sometimes the problems of delay in sync audio it´s related to differences between the frame rate of the clips and the frame rate of the sequence. Could be any other reason?

Thank you , have a nice day

[Michael Gissing]

Don’t worry about the sequence settings saying 32 bit floating point. That is the internal processing in FCP only. Clips should be 16bit or 24bit 48Khz.

Dat machines record 16 bit btw.

The sync drift is likely to be .1%, the difference between 24 fps and 23.976 fps. You can try converting the speed on one long file and see if that is the correct slow down.

[Chuska Esteban]

Hi,

So you mean to change the speed of a clip at 99%, and see what happens? The thing is that I am doing the editing offline and them this will be convert to film.

What I wonder, is that I made the conversion from the original Red One clips to Apple Pro Ress, with the software of Red Rushes, and the resulting clips are at 24 frames per second. And them I imported to Final and drag them to a sequence and appeared the message to change the settings of the sequence and I said yes. So the sequence is a 24 frames per second….so, it should work…What has happened?

Have a lovely day and Thanks

[Chuska Esteban]

Hi again:

I have talked to the person who recorded the audio, and can´t tell me a what frame rate he recorded the sound with the Dat. ( I thought that with Audio recording it doesn´t matter the frame rate that you are recording on a camera but it seems that yes, it´s important, that you can record your audio on 24 or 25)

So I wonder if the problem is that the audio recorded on the Dat, wich they gave me on a CD as wav, has different speed that the audio recorded in the camera, (I mean with the clips with the sound of reference)

If this could be like this, so what do you recomend me? Because what I am editing it´s going to be transform to film and I have to send it to the sound editor and to the lab. So should I change the speed of the audio of the Dat in Final, how much ?
This thing is driving me crazy….

Thank you,

[Chuska Esteban]

Just one more thing, about the 23.98 we have recorded in Europe? I mean that the 23.98 frame it isn´t more in USA,? Or I am absolutely confuse..

Please, Help it´s absolutely welcome

[Michael Gissing]

Audio has a sample rate, not a frame rate. If your wav files are broadcast wav and have timecode data then frame rate matters.

If the sync is drifting then we need to know a few more details. When you made the ProRes files in RedRushes, did you make them at 24 or 23.976 frames? The RED should have been shooting 24 but don’t presume anything. It might have been set to 23.976.

You need to confirm that the camera was on true 24, the file conversion in REDRushes was also 24 and that you sequence settings are 24. If at any stage 23.976 enters the equation then it will be slowing down your pictures by -.1%.

Is your audio faster or slower?

[Chuska Esteban]

Thank so much for your answer, today I have checked the original material of the Red One, and it is in 24 frames. I just slowed down the audio at 99.9% and Great, the audio was perfectly in sync!!!!!

Finally!!!! Thank so much!!!!