Apple Final Cut Pro 5 - Manual (Page 1712)

Appendix A Video Formats 361
V
Color Recording Method
The color recording method of a video format may be either RGB, component (Y´C
B
C
R
),
S-Video (Y/C), or composite. The more discrete channels a format has, the higher the
quality of the image, but the more data required to store and transmit that
information.
Today, almost all digital video formats are component Y´C
B
C
R
, as well as analog formats
such as BetacamSP. Computers typically store image data using RGB, although many
component (Y´C
B
C
R
) formats can now be natively processed on the computer (such
as DV).
Video Sampling Rate and Color Sampling Ratio
The video sampling rate of a digital video format determines how often the light
intensity of each video line is sampled.
Color recording method Video formats
Composite 1”, 3/4” U-matic, 1/2”, VHS, D-2, D-3.
S-Video (Y/C) Hi8, S-VHS.
Component (Y´C
B
C
R
) BetacamSP, Digital Betacam, DVD, DV, D-1, D-5.
RGB Computer video and graphics files; this format is rare for tape
formats.
Sampling Rate Description
14.3 MHz Early NTSC digital video recorders sampled video at exactly four
times the frequency of the color subcarrier signal (3.58 MHz x 4).
This is the origin of the 4 in color sampling ratios such as 4:2:2.
13.5 MHz This is the sampling rate for the luma (Y) channel for standard
definition digital video. This sampling rate was chosen to work with
both NTSC and PAL digital video. The 4 in the 4:2:2 is now
represented by this sampling rate.
6.75 MHz This is the sampling rate for the color difference channels in 4:2:2
video. This is half of 13.5 MHz.