Codecs en Fedora 18

Recuerda que debes tener instalado los repositorios RpmFusion.

yum -y install gstreamer-plugins-bad gstreamer-plugins-bad-free-extras gstreamer-plugins-bad-nonfree gstreamer-plugins-ugly gstreamer-ffmpeg

yum -y install gstreamer1-libav gstreamer1-plugins-bad-free-extras gstreamer1-plugins-bad-freeworld gstreamer1-plugins-base-tools updates gstreamer1-plugins-good-extras gstreamer1-plugins-ugly gstreamer1-plugins-bad-free gstreamer1-plugins-good gstreamer1-plugins-base gstreamer1

Extras

ffmpeg 
yum -y install ffmpeg

Mencoder
yum -y install mencoder

ffmpeg2 theora
yum -y install ffmpeg2theora

Mplayer
yum -y install mplayer

Reproducción de DVD cifrados
yum -y install libdvdread libdvdnav lsdvd libdvdcss

Agregar Repositos ThirdParty en Fedora 18

RPM Fusion - Community Repositories

yum -y localinstall http://mirror.yandex.ru/fedora/russianfedora/russianfedora/nonfree/fedora/russianfedora-nonfree-release-stable.noarch.rpm

yum localinstall --nogpgcheck http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-18.noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-18.noarch.rpm

yum -y localinstall http://mirror.yandex.ru/fedora/russianfedora/russianfedora/free/fedora/russianfedora-free-release-stable.noarch.rpm

Instalación de Fedora 18

Como instalar Fedora 18 "Spherical Cow" (Explicado)