sudo yum install epel-release -y
 sudo yum update -y
 sudo shutdown -r now  
sudo rpm --import ​​http://li.nux.ro/download/nux/RPM-GPG-KEY-nux.ro​​​ sudo rpm -Uvh ​​http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-5.el7.nux.noarch.rpm​​
sudo yum install ffmpeg ffmpeg-devel -y