Installation of MPEG/H.264 Decoder and VLC Player installation
Follow the following steps
1. yum install epel-release
//To install elrepo
2.rpm -Uvh http://li.nux.ro/download/nux/dextop/...
// For installation of nux repo
Now main part is installation of VLC Player and other plugins/Decoder.....
3. yum install vlc* gstreamer1-libav-1.0.6-1.el7.nux gstreamer1-vaapi gstreamer1-plugins-bad-free-1.4.5-6.el7 libdvdcss gstreamer{,1}-plugins-ugly gstreamer-plugins-bad-nonfree gstreamer1-plugins-bad-freeworld libde265 x265 gstreamer-ffmpeg gstreamer1-vaapi-debuginfo-0.6.1-1.el7.x86_64 smplayer HandBrake-{gui,cli}
In my case i was not able to install HandBrake-{gui,cli}, gstreamer-ffmpeg & gstreamer1-vaapi due to some problem, but you install these rpm's . But still you can watch the videos without installation of these packages.
If any other problem comes, you can write in comments....