DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

The P B and P R scale factors are
appropriate only for component
analog interfaces. Consult C B C R
components for SDTV, on page 305,
for details concerning scale factors
for component digital systems;
consult UV components, on
page 336, for details concerning
scale factors for composite analog
or digital NTSC or PAL.
Some systems, such as 480i studio video in Japan, use
a picture-to-sync ratio of 10:4 and zero setup. In this
case, unity in Equation 41.1 corresponds to 5 ⁄7 V, about
714 mV:
5
2
V'sync = ( active ⋅V')
+ −sync
7
7
( )
Many systems – such as computer framebuffers using
the levels of the archaic EIA RS-343-A standard – code
component video similarly to composite video, with
10:4 picture-to-sync ratio and 7.5% setup:
3 37
2
V'sync = active + ( active ⋅V')
+ −sync
56 56
7
For details, see Setup on page 514.
( )
Use of sync-on-green (RG S B) in computer monitor
interfaces was once common, but separate sync (RGBS)
is now common.
Component analog Y’PBPR interface, EBU N10
The PB and PR color difference components of analog
video are formed by scaling B’-Y’ and R’-Y’ components,
as described in PBPR components for SDTV on
page 303. Wideband PB and PR components are theoretically
possible but very rarely used; normally, they are
lowpass filtered to half the bandwidth of luma.
Y’, P B, and P R signals are conveyed electrically according
to Analog electrical interface and Analog mechanical
interface, on page 408.
Component Y’P B P R signals in 480i are sometimes interfaced
with zero setup, with levels according to the EBU
Tech. N10 standard. Zero (reference blanking level) for
Y’, P B, and P R corresponds to a level of 0 V DC, and unity
corresponds to 700 mV. Sync is added to the luma
component; sync is taken to be unity when asserted
and zero otherwise:
( )
7 3
Y'sync = Y'+ −sync
10 10
508 DIGITAL VIDEO AND HDTV ALGORITHMS AND INTERFACES
Eq 41.4
Eq 41.5
Eq 41.6