DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

Nit Candela per meter squared, cd·m -2 (colloquial). Derived from the
Latin nitere, to shine.
Normal line sync In analog SDTV, a line sync pulse that remains at sync level for
about 4.7 µs. In interlaced systems, the leading edge of equalization
and broad pulses are utilized as line syncs.
Notch filter In a composite video decoder, circuitry that separates chroma
from a composite signal using a simple bandpass filter centered at
the color subcarrier frequency. A notch filter introduces dot crawl
artifacts into any picture that has luma detail at frequencies near
the color subcarrier.
NTSC, National Television
System Committee
1. The group, now referred to as NTSC-][, that in 1941 standardized
525-line, 60.00 Hz field rate, interlaced monochrome television
in the United States.
2. The group, formally referred to as NTSC-][][, that in 1953 standardized
525-line, 59.94 Hz field rate, interlaced color television
in the United States. NTSC-][][ introduced the composite video
technique.
3. A method of composite video encoding based on quadrature
modulation of I and Q (or U and V) color difference components
onto a color subcarrier, then summing the resulting chroma signal
with luma. Used only with 480i scanning, with a subcarrier
frequency nominally 455 ⁄2 times the horizontal line rate (i.e.,
a subcarrier frequency of about 3.579545 MHz).
4. Often incorrectly used to denote 480i29.97 (525/59.94) scanning.
NTSC-4.43 A degenerate version of NTSC (3), having 480i scanning and
NTSC chroma, but with chroma modulated onto a 4.43 MHz color
subcarrier instead of 3.58 MHz. NTSC-4.43 is utilized by some
European consumer equipment to play NTSC tapes. Provided the
scanning range encompasses 15.734 kHz horizontal and 59.94 Hz
vertical rates, the use of a 4.43 MHz color subcarrier eliminates
the 3.58 MHz crystal that would otherwise be required.
NTSC-J NTSC as used in Japan: NTSC (3) with zero setup (and luma and
chroma levels modified accordingly).
NTSC-legal The condition where an NTSC signal is R’G’B’-legal and additionally
has no chroma content that would cause the composite signal
to exceed +120 IRE units.
Odd field In 480i (interlaced) scanning, the field whose first broad pulse is
coincident with line sync. Compare Even field, on page 628. The
terms odd and even should be avoided, and first and second used
instead.
OFDM Orthogonal frequency-division multiplexing. In video transmission,
OFDM is always applied to digital data, and referred to as
coded; see COFDM on page 619.
GLOSSARY OF VIDEO SIGNAL TERMS 639