Since I was struggling a bit with installing FFMPEG php extension in Plesk using CentOS7, I wrote a quick how-to. Maybe it will help some other users.
1. Make sure EPEL is enabled
2. Enable RPM Fusion
# yum localinstall --nogpgcheck
https://download1.rpmfusion.org/free/el/rpmfusion-free-release-7.noarch.rpm https://download1.rpmfusion.org/nonfree/el/rpmfusion-nonfree-release-7.noarch.rpm
3. install ffmpeg and dependencies
# sudo yum install ffmpeg ffmpeg-devel mplayer mencoder flvtool2 libogg libvorbis lame
# sudo yum install make plesk-php56-devel gcc glibc-devel zlib-devel
4. Download ffmpeg-php. For CentOS 7 you can use my fork as the default will look foor FFMPEG headers in the wrong location ( configure: error: ffmpeg headers not found. · Issue #24 · tony2001/ffmpeg-php · GitHub ).
# git clone
GitHub - nilsringersma/ffmpeg-php: PHP extension for video editing, wrapping ffmpeg
# cd ffmpeg-php
# /opt/plesk/php/5.6/bin/phpize
5. Configure & make
# ./configure --with-php-config=/opt/plesk/php/5.6/bin/php-config --enable-skip-gd-check
# make
# make install
6. Enable the extension
# echo "extension=ffmpeg.so" > /opt/plesk/php/5.6/etc/php.d/ffmpeg.ini
# plesk bin php_handler --reread