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Adding and removing pull-down in 24p clips, Adding and, Removing pull-down in 24p clips – Apple Cinema Tools 4 User Manual

Page 217: What is 2:3:2:3 pull-down

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Adding and Removing Pull-Down in 24p Clips

Cinema Tools and Final Cut Pro have pull-down removal and addition features that address
issues specific to working with 24p video. Pull-down is a process that adds redundant
fields to video in order to distribute 24 frames per second into the NTSC standard of
29.97 frames per second. See

Frame Rate Basics

for more information. Some camcorders,

such as the Panasonic AG-DVX100, are designed to shoot in progressive mode at 24 fps
(literally 23.98 fps) and then record the video to tape as a 60-field interlaced signal by
applying a special kind of pull-down called advanced 2:3:3:2 pull-down. With Final Cut Pro
or Cinema Tools, you can remove the redundant fields created by the camera’s pull-down,
so that you can edit at 23.98 fps or 24 fps.

When you edit 23.98 fps video, you may need to output it to an NTSC monitor, record it
to an NTSC videotape, or send it to another type of NTSC device. Because the NTSC
standard specifies a frame rate of 29.97 fps, Final Cut Pro gives you a way to add pull-down
back in to the video as you output it. To accommodate various circumstances, Final Cut Pro
provides a few different types of pull-down patterns for outputting your 23.98 fps video
as 29.97 fps video: 3:2 pull-down, 2:3:3:2 pull-down, and 2:2:2:4 pull-down. (See

Pull-Down

Patterns You Can Apply to 23.98 fps Video

for a description of these pull-down patterns.)

The sections that follow describe a number of ways that you can use Final Cut Pro or
Cinema Tools to remove advanced 2:3:3:2 pull-down or 2:3:2:3 pull-down from digital
video clips. You can:

• Use Final Cut Pro to remove 2:3:3:2 pull-down while capturing, or after capturing

• Use Cinema Tools to remove 2:3:3:2 or 2:3:2:3 pull-down on one clip at a time

• Use Cinema Tools to remove 2:3:3:2 or 2:3:2:3 pull-down on several clips at a time

What Is 2:3:2:3 Pull-Down?

A 2:3:2:3 pull-down pattern is exactly the same as a 3:2 pull-down pattern, except that
it is applied by a digital video camcorder (as opposed to any other type of equipment
that could apply the same pattern of pull-down). This manual uses the term 2:3:2:3 when
referring to the pull-down that comes from a 24p digital video camcorder; this type of
pull-down can be removed using the automated form of reverse telecine. See

Removing

2:3:3:2 or 2:3:2:3 Pull-Down with Cinema Tools

for more information.

217

Chapter 13

Working with 24p Video and 24 fps EDLs