ffmpeg-php is an php module, so it need to installed on server, not on domain. Once this is installed, you will be able to see it in php info, just like other php modules.

Check the phpinfo at

http://video.bizhat.com/phpinfo.php

Search for text "ffmpeg", you will see.

ffmpeg
ffmpeg support (ffmpeg-php) enabled
ffmpeg-php version 0.5.0
libavcodec version Lavc51.28.0
libavformat version Lavf51.7.0

Directive Local Value Master Value
ffmpeg.allow_persistent 0 0