Hi,
The package is refreshed. Please download again and give it a try.
For building from source code, please try the steps:
download source code
$ echo "deb-src https://repo.download.nvidia.com/jetson/ffmpeg main main" | sudo tee -a /etc/apt/sources.list
$ sudo apt update
$ apt source ffmpeg
build
ffmpeg-4.2.7$ ./configure --enable-nvv4l2dec --enable-libv4l2 --extra-libs="-L/usr/lib/aarch64-linux-gnu/tegra -lnvbufsurface -lnvbufsurftransform" --extra-cflags="-I /usr/src/jetson_multimedia_api/include/"
ffmpeg-4.2.7$ make
decode mp4 file
ffmpeg-4.2.7$ ./ffmpeg -c:v h264_nvv4l2dec -i /home/nvidia/test.mp4 a.yuv