Fusion 878A
2.0 Functional Description
PCI Video Decoder
2.10 Video Data Format Conversion
100600B
Conexant
2-31
sub-sampling is achieved. In the YUV9 format, lines 2–4 of Cr/Cb data are
discarded, and hence 4:1:1 vertical sub-sampling is achieved.
2.10.6 Byte Swapping
Before the data enters the FIFO it passes through a 4-way MUX to allow
swapping of the bytes to support Macintosh (big endian) color data formats. The
pixel DWORD PD[31:0] maps onto the FIFO input FI[31:0]. The byte-swap
MUX remaps the data bytes, but byte lane 0 or bits[7:0] will still be considered
the first byte of the scan line. See
.
Table 2-6. Byte Swapping Map
Word Swap
0
1
Byte Swap
0
1
0
1
FIFO Inputs
Outputs of FIFO Data Formatter
FI[31:24]
PD[31:24]
PD[23:16]
PD[15:8]
PD[7:0]
FI[23:16]
PD[23:16]
PD[31:24]
PD[7:0]
PD[15:8]
FI[15:8]
PD[15:8]
PD[7:0]
PD[31:24]
PD[23:16]
FI[7:0]
PD[7:0]
PD[15:8]
PD[23:16]
PD[31:24]
NOTE(S):
The byte swapping mode is disabled during VBI data.
