DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

Eq 42.6
Eq 42.7
SMPTE 259M, 10-Bit 4:2:2
Component and 4f SC Composite
Digital Signals – Serial Digital
Interface.
be unity when asserted and zero otherwise; burst is in
the range ±1.
In composite 480i with setup, the expressions are
these:
5 ⎛ 601 ⎞ 2 ⎛ burst ⎞
NTSCsetup = ⎜ setupY'+ setupC⎟
+ − sync
7 ⎝
⎠ 7
⎜
⎟
⎝ 2 ⎠
The excursion of 480i luma, from synctip to reference
white, ranges from -40 IRE to +100 IRE. When
maximum chroma is added, the composite signal
reaches a minimum of -23 1 ⁄3 IRE (on 100% saturated
blue and red colors), and a maximum of 130 5 ⁄6 IRE (on
100% saturated cyan and yellow colors).
In the zero-setup NTSC system used in Japan, luma and
modulated chroma are summed as follows:
5
NTSCJ = ⎛ 601
Y' + C⎞
7 ⎝ ⎠
The composite NTSC-J signal reaches a minimum of
-33 1 ⁄3 IRE and a maximum of 133 1 ⁄3 IRE.
Composite digital NTSC interface (4f SC )
2 ⎛ burst ⎞
+ ⎜ − sync
7
⎟
⎝ 2 ⎠
Digital composite NTSC – also known as the 480i
version of 4f SC – is formed by scaling and offsetting
Equation 42.6 so that in an 8-bit system blanking (zero
in the equation) is at codeword 60 and reference white
is at codeword 200. With zero setup, as in NTSC-J, the
luma excursion is 140 codes. With 7.5% setup, the
luma excursion is 129 1 ⁄2 codes – inconveniently, not an
integer number of 8-bit codes.
In a 10-bit system, the reference codes are multiplied
by four: The reference codes remain the same except
for having two low-order zero bits appended. Codewords
having the 8 most-significant bits all-one or allzero
are prohibited from video data. Figure 42.2 above
shows a waveform drawing of luma in a 4f SC NTSC
composite digital interface, with 7.5% setup.
Composite 4f SC NTSC is sampled on the I and Q axes.
The 0 H datum does not coincide with a sample
instant – 0 H is, in effect, located at sample number
516 DIGITAL VIDEO AND HDTV ALGORITHMS AND INTERFACES