Film at 24fps, telecine at 29,97, audio at 30. No sync.

[Steven Gonzales]

On dual system film, sound and picture are in sync (assuming the devices are working properly) when captured.

Then, during telecine, the picture is slowed down by .1% to fit evenly onto 29.97 video.

So to sync at 29.97, you have to slow down the audio by .1% to sync.

If you also reverse telecine to 23.97, you have removed extra video frames, but you are still slowed down, and to sync audio you have to slow it down by .1%.

Your other choice is to conform your reverse telecine clips to 24 fps in Cinema Tools, and edit in a 24 fps timeline. If you do this, you have sped the film back up again. In this situation, you could sync the unchanged audio.

I think you have either reverse telecine clips at 23.97, or if you have reverse clips at 24, then you have placed them in a 23.97 timeline, and they remain slowed down.

[Alex Saggese]

Hi Steven, Thank you for your reply.

I think maybe it didn’t fully explain what’s going on. I want to work in 24fps and use the audio without pulldown. Everything was captured properly. The audio synched at the telecine. What happens is:

If the reverse telecine is in 24fps, when I put my audio in the 24 fps timeline, it pulls up my audio. It even indicates it on my timeline saying that it’s using a sample rate conversion to play. Well it shouldn’t do anything, it should leave my audio unchanged so that it syncs.

If the reverse telecine is in 23,98, it doesn’t do anything to my audio, but it should perform a pulldown.

My guess is that it’s assuming my audio timecode is 29,97 NDF instead of 30 NDF, so it thinks it needs a pullup for 24 and no action for 23,98. I haven’t managed to import the audio in 30 NDF, and I haven’t seen any options for that. I want it to assume that my audio doesn’t need change in a 24 fps timeline.

Thank you again,

Alex

[Steven Gonzales]

Don’t think about timecode frame rates.

Open one of your audio clips with quicktime, then under “window” menu select “show movie info”.

What is the format of the audio? 29.97 df, ndf, 30 ndf is all frame rates for timecode, they are not rates for audio.

Then open one of your reverse telecine clips with quicktime, and do the same thing. What is the format?

[Alex Saggese]

Reverse Telecine equals 24 fps, audio equals 48000Hz. I know that if the audio is played at the sample rate at which it was captured it will sync with my video at 24, but FCP won’t let me play the audio at that rate. It performs a pullup. It tells me it’s performing a pullup, it shows it right at the timeline.

I still think the problem is the timecode based, because if I convert the audio to aiff, for example, that has no timecode stamp, using the same sample rate, it works.

I think that the pullup happens because it assumes that the TC is 29,97, and to sync to 24, it needs a pullup.

[Steven Gonzales]

Now what is the item properties on the sequence you are putting these into?

[Gary Adcock]

[Alex Saggese] “Reverse Telecine equals 24 fps, audio equals 48000Hz.”

NO- not if you are converting 29.97 material- it should be 23.98 (23.976 for AE users) frames per second.

[Alex Saggese] “FCP won’t let me play the audio at that rate. It performs a pullup. It tells me it’s performing a pullup, it shows it right at the timeline. “

What? there is no such thing as “audio pullup”
First OFF- Audio files do not have frame rates, there are no frames in audio, audio is measured in feet and inches or minutes and seconds- there are not now nor have ever been frames in Audio.

[Alex Saggese] “I still think the problem is the timecode based, because if I convert the audio to aiff, for example, that has no timecode stamp, using the same sample rate, it works. “

Any issues would be in how you are handling the file- since your own test above explains my answer.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD

[Alex Saggese]

Sequence is set to DV compressor Timebase 24 Audio Rate 48 kHz. Video plays fine. Audio captured from tape is also in sync. Imported audio does a sample rate conversion to speed up the audio when I place it on the timeline.

Alex

[Gary Adcock]

[Alex Saggese] “ideo plays fine. Audio captured from tape is also in sync. Imported audio does a sample rate conversion to speed up the audio when I place it on the timeline. “

It is speeding up the audio to match the video – separate the audio from the video and it should play correctly.( just as you did with the Aiff file)

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD

[Steven Gonzales]

What machine were the sound recordings made on? What were the setting on the sound recorder?

[Alex Saggese]

I think I can work in either 24 or 23,98. The difference is that using 23,98 I can output directly to firewire, but I don’t need that. With the reverse telecine at 24, my media goes back to its original speed and I shouldn’t need to pulldown the audio.

Audio files don’t have frame rates but are recorded with a timecode. The timecode is used to inform most systems about pulldown. For example. if you record DATs on location in 30 NDF and perform a telecine to 29,97 when you pulldown your DAT player, the TC rate will also be 29,97. That sounds uninportant in the computer world we live today, but if you’re synching between your DAT player and your Beta recorder, it won’t work if your DAT was not recorded at 30 NDF. There’s no way it will sync, so the audio timecode is important.

BWF files have a starting timecode on them, and that timecode is important for post production. The starting timecode is recorded the following way: The number of samples since midnight, so if you use 29,97 or 30 you will get a different starting timecode and the timecode will have a different rate during play. I can’t have that, so I need it to have the right timecode.

If audio is sped by .1% some people call it a pullup, so that’s why I used the term. When your final product is going to be film cut from negative, but all your audio is mixed at 29,97 using video tapes, you need to perform an audio “pullup” to sync back to your film. In reality you’re just removing the pulldown.

On my telecine tapes, I only get 2 channels, but on my BWF files, I get 4. I need them all, so I can’t use the audio from the tapes only.

I know the problem is how I’m handling the audio files, and I think it’s got something to do with the way I import them in FCP. In other systems that cut film, it really matters for your sync if you import your audio in 29,97 or 30. I haven’t seen that option in FCP and for some reason it’s trying to change the speed of my audio when it doesn’t need to, so I’m assuming that’s the reason.

It’s my first time cutting film in FCP, I’ve always used Avid. I’m a fan of FCP and would like to give it a try.