DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

Only CN/PAL is deployed today –
in other words, all N/PAL systems
in use are actually CN/PAL.
Eq 48.1
DB= ⎛ 601
1. 505 B'− Y'⎞
⎝ ⎠
DR=− ⎛ 601
1. 902 R'−Y'⎞ ⎝ ⎠
Brazil uses PAL-M (formally M/PAL, sometimes denoted
PAL-525), which has 480i scanning and PAL color
encoding with a subcarrier close to 3.58 MHz (but not
exactly that of NTSC).
Argentina, Paraguay, and Uruguay use system PAL-N
(formally N/PAL or CN/PAL, also known as PAL-3.58).
System N refers to 576i scanning with a bandwidth of
about 4.2 MHz. N/PAL has a color subcarrier frequency
close to 3.58 MHz (but not exactly the same as NTSC).
Historically, monochrome System N had 7.5% setup and
a picture-to-sync ratio of 10:4, but when color broadcasting
was introduced, setup was eliminated and
picture-to-sync ratio was altered to conform to PAL
conventions. Use of 7:3 picture-to-sync ratio is denoted
by C (for combination) preceding N-PAL.
SECAM
SECAM is an acronym for séquentiel couleur à mémoire.
This system is used with 576i scanning for terrestrial
VHF and UHF broadcasting in France, Russia, and a few
other countries. SECAM uses neither quadrature modulation
nor frequency interleaving. Line-alternate color
difference components are scaled (see Equation 48.1) to
form DB and DR, equalized (preemphasized), then
frequency-modulated (FM) onto a subcarrier. The
resulting deviation ranges from about 3.9 MHz to
4.75 MHz, roughly the frequency range of PAL or NTSC
modulated chroma. This FM chroma signal is then
summed with luma, which has been notch-filtered in
the region of the chroma subcarrier. Since the color difference
components are transmitted line-sequentially,
a SECAM receiver requires a one-line (1H) delay to
recover chroma. SECAM has no coherent subcarrier per
se, but has a pair of reference rest frequencies that are
related to the line rate. Each video line includes a burst,
alternating between DB and DR rest frequencies.
Systems D, K, and L use 576i scanning. D/SECAM and
K/SECAM are used in the nations of the former USSR;
System L/SECAM is used in France. The systems differ in
their video and audio modulation. MESECAM is a VHS
videotape format used in the Middle East. It is not
a broadcast standard. (See page 584.)
576 DIGITAL VIDEO AND HDTV ALGORITHMS AND INTERFACES