PNX1301 PHILIPS [NXP Semiconductors], PNX1301 Datasheet - Page 101

• Manufacturer Part Number: PNX1301
• Description: Media Processors
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
Figure 6-6. Chrominance re-sampling to achieve interspersed sampling.
Figure 6-7. Filtering at the edge of the active area.
Figure 6-8. Format of CCIR656 SAV and EAV timing reference codes.
Figure 6-9. VI capture parameters.
VI_CTL.SC=1: ‘Interspersed sampling’ serves to gen-
erate a sampling structure in memory where chromi-
nance samples are spatially midway between luminance
samples, as shown in
mat is suitable for use in MPEG-1 encoding.
The VI hardware applies a (–1 13 5 –1)/16 filter as illus-
trated in
writing them to memory. This filter computes chromi-
nance values at sample points midway between lumi-
nance samples
Figure 6-6
1
1 1 1 1 1 1 1 1
. Computed video data is clamped to
d
to the chrominance samples before
c
Figure
YUV 4:2:2 CCIR656
b
Resampled sample
a
input samples
6-6. This ‘interspersed’ for-
b
c
values
d
0 0 0 0 0 0 0 0
Timing reference code
Pixel 0
START_X
e
a
a
f
Preamble
b
b
g
c
c
h
START_Y
Captured Image
d
d
i
e
e
WIDTH
j
Active area
f
f
• • •
0 0 0 0 0 0 0 0
g
g
V = 1 during field blanking
01h if the filter result is less than 01h and clamped to FFh
if greater than FFh. Interspersed d ata format is preferred
by some video compression standards. The MPEG-1
standard, for example, requires YUV 4:2:0 data with
chrominance sampling positions horizontally and verti-
cally midway between luminance samples. This can be
achieved from the horizontally interspersed sampling for-
PRELIMINARY SPECIFICATION
1.
h
h
F = 0 during field 1
F = 1 during field 2
Pixel M–1
zs zt
i
i
All filters perform full precision intermediate computa-
tions and saturation upon generating the result bits.
V = 0 elsewhere
j
j
zu zv zw zx zy zz zy zx zw
Line 0
Line N–1
Y
U
V
g
k
k
ef
ef
'
=
=
=
Y
l
l
g
–
–
U
V
c
c
+
+
1 F V H P P P P
13U
13V
e
e
+
+
5U
5V
g
g
–
–
U
V
i
i
H = 0 for SAV
H = 1 for EAV
16
16
Protection bits
(error correction)
Video In
6-5