直接用yum安装是找不到源文件的
sudo yum localinstall --nogpgcheck http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-27.noarch.rpm
sudo yum localinstall --nogpgcheck http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-27.noarch.rpm
sudo yum update
sudo dnf install vlc unrar
sudo dnf install smplayer这样就可以搞定了