最近我在尝试编译opencv，安装依赖项libjasper1和libjasper-dev的时候就遇到了这个问题。在amd64平台上，我们可以通过下面的命令安装（ubuntu18.04）
apt-get install -y software-properties-common
add-apt-repository "deb http://security.ubuntu.com/ubuntu xenial-security main"
apt-get -y update
apt-get install -y libjasper1 libjasper-dev
但是在arm64的机器上，这个新添加的源会提示404。注意404不是网络问题，而是指定的文件不存在。根据这里显示的url，其实就是因为binary-arm64这个路径不存在。
Err:6 http://security.ubuntu.com/ubuntu xenial-security/main arm64 Packages
404 Not Found [IP: 185.125.190.83 80]
Fetched 106 kB in 2s (44.6 kB/s)
Reading package lists... Done
E: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/main/binary-arm64/Packages 404 Not Found [IP: 185.125.190.83 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.