SAA7118 Datasheet, PDF (58/169 Pages) NXP Semiconductors – Multistandard video decoder with adaptive comb filter and component video input

Philips Semiconductors
Multistandard video decoder with adaptive
comb filter and component video input
Preliminary specification
SAA7118
unscaled input
field 1
field 2
scaled output,
no phase offset
field 1
field 2
scaled output,
with phase offset
field 1
field 2
scale dependent start offset
mismatched vertical line distances
correct scale dependent position
MHB547
Fig.35 Basic problem of interlaced vertical scaling (example: downscale ³â„₅).
field 1
upper
field 2
lower
A
field 1
case UP-UP
field 2
case LO-LO
B
field 1
case UP-LO
field 2
case LO-UP
C
D
MHB548
Offset = ^{1----30---22---4--} = 32 = 1 line shift
OA ff₌se12-t- _i=_{np1-u---30t---22-l-i-n4--e}=_{sh3if2t == 116line} shift
BA == ^12-12--- iinnppuutt lliinnee sshhiifftt +=^12--1s6cale increment = ^{Y----S----C-----Y6---4-[-1----5---:--0---]} + 16
C = ^12-- scale increment = ^{Y----S----C-----Y6---4-[-1----5---:--0---]}
DB =₌n12-o- _{ionfpfsuettli=ne0shift +} ^12-- _{scale increment =} ^{Y----S----C-----Y6---4-[-1----5---:--0---]} _{+ 16}
C = ^12-- scale increment = ^{Y----S----C-----Y6---4-[-1----5---:--0---]}
D = no offset = 0
Fig.36 Derivation of the phase related equations (example: interlace vertical scaling down to ³â„₅, with field
conversion).
2001 May 30
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