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Pixels per line – Apple Final Cut Pro 7 User Manual

Page 1900

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Pixels per Line

In digital video formats, each line is sampled a number of times. In an attempt to create
a single digital VTR that could digitize and record both NTSC and PAL signals, the ITU-R
BT.601 specification uses 720 samples per line for both NTSC and PAL video. Therefore,
a digital NTSC video frame is 720 pixels x 486 lines, and a PAL video frame is 720 pixels
x 576 lines.

HD video with 1080 lines uses 1920 pixels per line (1920 x 1080). HD video with 720 lines
uses 1280 pixels per line (1280 x 720). Both of these formats have an aspect ratio of 16:9.

Common video frame sizes are shown in the table below.

Description

Screen
aspect
ratio

Pixel
aspect
ratio

Height

Width

Used for web distribution or offline video editing.

4:3

1:1

240

320

An early standard for analog-to-digital video
editing, and an ATSC video specification.

4:3

1:1

480

640

NTSC DV and DVD image dimensions. Also part of
the ATSC video specification.

4:3

Height
greater
than
width

480

720

1

NTSC SD video dimensions used for professional
digital formats such as Digital Betacam, D-1, and
D-5.

4:3

Height
greater
than
width

486

720

1

PAL SD video dimensions used for digital formats
such as Digital Betacam, D-1, and D5, as well as
DVD and DV.

4:3

Width
greater
than
height

576

720

1

An HD video format, capable of higher frame rates
in exchange for smaller image dimensions.

16:9

1:1

720

1280

An HD video format with very high resolution.

16:9

1:1

1080

1920

Some 720p formats (such as DVCPRO HD and HDV)
subsample 1280 pixels to 960 to minimize the data
rate.

16:9

4:3

720

960

Some 1080-line formats (such as HDV and DVCPRO
HD) subsample 1920 pixels to 1440 or even 1280
to minimize the data rate.

16:9

4:3

3:2

1080

1440

1280

1 In most video devices, only 704 or 708 pixels are actually used for picture information.

Note: For information on pixels per line and aspect ratios in digital cinema formats such
as REDCODE, see Professional Formats and Workflows, available in Final Cut Pro Help.

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Appendix B

Video Formats