AMD Geode LX 800@0.9W - Manual (Page 473)

AMD Geode™ LX Processors Data Book 473
Video Input Port 33234H
Figure 6-48. BT.601 Mode Vertical Timing
6.9.9 YUV 4:2:2 to YUV 4:2:0 Translation
The VIP provides the option to translate incoming 4:2:2 co-
sited video to YUV 4:2:0. The U and V values of even lines
are simply discarded. No filtering is performed. VIP stores
the 4:2:0 data to system memory in a planar format. In pla-
nar format, the Y, U, and V data is partitioned into separate
buffers. A single Y, U, V buffer (three buffers) can be used
in the case of progressive scan or with interlaced data
when using Weave. Two sets of buffers (six buffers) are
used to store the odd and even field data separately when
using the Bob method of de-interlacing.
Figure 6-49 on page 474 illustrates the positioning of the
YCbCr samples for the 4:2:2 and 4:2:0 formats when:
1) Receiving a progressive scan frame.
2) Receiving interlaced odd and even fields for use with
the Bob display mode.
3) For receiving odd and even fields with the Weave dis-
play mode.
In addition to the standard 4:2:2 translation, VIP can also
decimate all U/V values in the even field.
C = 4
D = 7
E = 4
F = 7
HSYNC
VSYNC
(even field)
VSYNC
(odd field)
C - vertical_start for 601 odd field (VIP Memory Offset 6Ch[11:0])
D - vertical_end for 601 odd field (VIP Memory Offset 6Ch[27:16])
E - vertical_start for 601 even field (VIP Memory Offset 48h[11:0])
F - vertical_end for 601 even field (VIP Memory Offset 48h[27:16])
Video Data
** Frame timing starts at leading edge of VSYNC
1 2 3 4 5 6 7 8
G = 2
H = 3
VSYNC
G - vbi_start for 601 (VIP Memory Offset 44h[11:0])
H - vbi_end for 601 (VIP Memory Offset 40h[11:0])
VBI Data