1. centos 7 all repo
https://pkgs.org/
2. install by rpm
http://glidingphenomena.blogspot.com/2020/02/how-to-fix-error-requires.html
3. remove pid
[root@localhost yum.repos.d]# rm -rf /var/run/yum.pid
4. yum instruct
yum info
rpm -ql
5. extract package
[root@localhost ffplay_test]# rpm2cpio ffplay-2.8-4.el7.centos.x86_64.rpm | cpio -idmv