I'm attempting to build FFmpeg from source for the Rockchip 3399 and not able to get it working so far. The `ffmpeg -benchmark -loglevel 48 -vcodec h264_rkmpp -i b85.mp4 -map 0:v:0 -f null -` command for example, produces a segmentation fault along with a message indicating the MPP context and RKMPP...

I'm using the rk3399-sd-friendlycore-lite-focal-5.14-arm64-2022051.img on a NanoPI R4S and would like to compile the kernel from source. The kernel version is 5.15.11 and I don't see a similarly tagged branch in the github (https://github.com/friendlyarm/kernel-rockchip).