The video decoder unit (VDU) decompresses h.264 and h.265 video streams. The VDU is a device option where a device can include zero, two, or four units. Each VDU can be used by itself or combined with one or more other decoder units to achieve higher decoding throughput. The maximum number of video streams that can be decoded based on resolution and a single VDU is shown in the following table.
| Resolution and Refresh Rate | Number of Video Streams |
|---|---|
| 4K 60p | 1 |
| 4K 30p | 2 |
| 1080 30p | 8 |
| 720 30p | 16 |
| 720 15p | 32 |
The VDU interfaces to the PL via two 128-bit AXI ports for the decoder to access memory. The VDU also includes a 32-bit AXI port for its control unit to access memory. The VDU also has a 32-bit APB (or AXI4-Lite) port for register programming.