Audio Pull-up/down... How does it work?

Hello experts,

Im new to this whole video postproduction world. Read the manual, but I don´t quite understand how does this work.

Anyone care to explain how to choose which option to use from the Audio Pull up/down menu in project setup?

As you can see I´m completely lost here. :mrgreen: Please help! I really need to understand this!

First you need to explain what you want to achieve. :wink: It doesn’t have any use unless you need to alter the project or the export.

Well, that is my dilemma AlexBell, I´m writing a Nuendo course so I need to know what the function is used for, beyond showing the available options or copying what the manual says about them. I need to know “real world situations” where each option is relevant, useful and beneficial, but I don´t have access to movie footage transferred to NTSC or PAL video.

Do you see my predicament?

That is indeed a predicament! :open_mouth:

Is this for college or something? Lynda.com or Mac ProVideo may have courses, that your “audience” can watch, instead of putting yourself through this.

When your project is in framerate “A” and the delivered video is in another framerate (B), you can “force” the video/project to play back at the other framerate, so both align.

Fredo

So, when “B” > “A”, is that “pulling up” ?

Thanks Fredo, that Makes perfect sense. Can you provide a “real life example” of when this kind of work would be necessary for commercial products?

Say that you have made a 30" TV commercial.
That TV commercial runs @ 25fps.
Clients also needs a version for Cinema.
DCP is running @ 24fps.
So the 25fps video will be running slower in cinema, and as a result will run for 31,250 seconds instead of 30". (-4%)
You, on the other hand, need to deliver audio that is 31.250 seconds long. (to match the longer video-running time)

There are different ways to do that.
The most common practice is stretching the audio. Making it longer, and pitching it up again.

Using pull, you can actually “pull” your audio session, so it runs for 31,250 seconds, thereby eliminating the stretch-process.
(You are actually faking that your session runs at slightly lower sampling frequency than 48kHz)

You will however need to (re)record the output of your session into another recorder.
Like it was done in the old times - re-recording the masters on another machine-
Exporting or re-recording within the same project will not work, since you are still locked to your 48kHz Houseclock.


HTH
Fredo

Oh I see now! Ok thanks a lot Fredo!

Anybody else with examples on how you´ve used Audio Pull up/down?

All examples are welcome! Please be as thorough as you want!

Would pull down be stretching? And pull up compressing? Does anyone knows how to use the resample tool to “stretch” or compress from 2398 fps to 24? is it the right way? I have a 2398 video hour long stereo mix that needs to be turn into 24 fps for a dcp and then a 25 version for a tv channel. I know the n I would have to use the time stretch and pitch , but someone was talking that the first conversion shold be done with the resample tool…I really dont know and need help. I am opening another thread but thought maybe someone knows here (@Fredo) . Also @hesca116 shurely knows more by now abot this. Thanks!!

@fredo might correct me if I´m wrong here. According to Nuendo’s manual you need to:

  1. Import your 23.98 video to Cubase/Nuendo and activate “extract audio”
  2. Activate the +0.1% pullup to make your session audio sync with 24fps
  3. Work your audio, export it. Thats your 24fps mix
  4. Import that 24 fps audio to Cubase/Nuendo and do another pullup, this time choose +4.16% to achieve audio sync with 25fps

According to Nuendo´s manual, 24 fps is the core format for frame rate conversion. Footage comes at 24pfs, and from there you either do a +4.16% to get 25fps for PAL video, or you do -0.1% pulldown to get 23.98 and then apply a 2-3 pulldown to achieve 29.97fps for NTSC video

Now, this has nothing to do with the question, but NTSC gets confusing for me because if you import a 24 fps video with its own audio and you want NTSC audio output, then I´m not sure if you´d have to setup the video frame rate at 30 fps or leave it at 24 fps.
I think you´d have to begin by importing a 30fps video to be able to do a -0.1% pulldown in order to get 29.97 fps and be able to export NTSC audio.

Anyone care to explain?