The Video Processing Subsystem supports chroma resampling between 4:4:4 and 4:2:2 formats as well as between 4:2:2 and 4:2:0.
Figure 1. 4:2:2 – 4:4:4 Chroma Resampling Tab
Figure 2. 4:2:0 – 4:2:2 Chroma Resampling Tab
The parameters on the Chroma Resampler tabs are as follows:
- Algorithm
-
- Drop Repeat
- Using the drop option results in down conversion with no filter. Some samples are passed directly to the output, but others are dropped entirely, as appropriate. This occurs on a line-by-line basis and on a pixel-by-pixel basis. The replicate option is available in all upconverters. It applies in both vertical and horizontal domains as appropriate. Using the replicate option results in up conversion with no filter. Replication of the previous input sample occurs instead.
- Predefined
- Filters are predefined and not programmable. The filters use only power-of-two coefficients so no DSP48s are necessary. Linear interpolation is employed for the low pass filters used for anti-aliasing and interpolation.
- FIR
- Used to program the filter coefficients through the AXI4-Lite interface.
- Filter Control
- When FIR filtering is selected, the number of Horizontal and Vertical taps are
defined here.
- Horizontal Taps
- Select 4, 6, 8, or 10 horizontal filter taps.
- Vertical Taps
- Select 4, 6, 8, or 10 vertical filter taps.