Texas Instruments TMS320C64x DSP Network Card User Manual


 
Video Output Filtering
4-21Video Display PortSPRU629
4.4 Video Output Filtering
The video output filter performs simple hardware scaling and resampling on
outgoing 8-bit BT.656 or 8-bit Y/C data. Filtering hardware is disabled during
10-bit or raw data display modes.
4.4.1 Output Filter Modes
The output filter has four modes of operation: no-filtering, 2× scaling, chromi-
nance resampling, and 2× scaling with chrominance resampling. Filter opera-
tion is determined by the DMODE, SCALE, and RESMPL bits of the VDCTL.
Table 43 shows the output filter mode selection. When 8-bit BT.656 or Y/C
display operation is selected, (DMODE = x00), scaling is selected by setting
the SCALE bit and chrominance resampling is selected by setting the
RESMPL bit. If 8-bit BT.656 or Y/C display is not selected (DMODE x00),
filtering is disabled.
Table 43. Output Filter Mode Selection
VDCTL Bit
DMODE RESMPL SCALE Filter Operation
x00
0 0 No filtering
x00 0 1 2× scaling
x00 1 0 Chrominance resampling (full scale)
x00 1 1 2× scaling with chrominance resampling
x01 x x No filtering
x10 x x No filtering
x11
x x No filtering