Vamos a ver paso a paso como se puede instalar el soporte PHP FFMPEG
1. Instalar RPMFORGE
https://www.rubenortiz.es/2008/11/11/openvz-rpmforge-para-centos-5/
2. YUM
# yum install ffmpeg ffmpeg-devel php-devel
3. PHP FFMPEG
# wget http://downloads.sourceforge.net/project/ffmpeg-php/ffmpeg-php/0.6.0/ffmpeg-php-0.6.0.tbz2?use_mirror=heanet
# wget ftp://217.113.242.100/linux/php/ffmpeg-php-0.6.0.tbz2
# tar -jxvf ffmpeg-php-0.6.0.tbz2
# cd ffmpeg-php-0.6.0
# phpize
# ./configure¡
# make
# make install
Installing shared extensions: /usr/lib64/php/modules/
4. Incluir la extensión compilada en la configuración de PHP
# vim /etc/php.ini
extesion=ffmpeg.so
5. Rebotar apache
# /etc/init.d/httpd restart
6. Comprobar
-bash-3.2# php -i |grep ffmpeg
ffmpeg
ffmpeg-php version => 0.6.0-svn
ffmpeg-php built on => Mar 24 2010 15:58:41
ffmpeg-php gd support => enabled
ffmpeg libavcodec version => Lavc52.20.0
ffmpeg libavformat version => Lavf52.31.0
ffmpeg swscaler version => SwS0.7.1
ffmpeg.allow_persistent => 0 => 0
ffmpeg.show_warnings => 0 => 0