Driver for the VPU ASIC on Raspbian Bookworm and co for RK-3328

Some time ago, I attempted to use this board to drive a few security cameras. The board saw extremely high CPU usage and slow frame rates, implying all of the H264 decoding from the cameras were being directed to the CPU and processed in software, not in the ASIC. A driver and a way to program for the VPU via OpenCV would be welcome.