For a start, for Ubuntu, you should almost always be using a Long Term Support edition, so that's 10.04.
Here's the reason - https://wiki.ubuntu.com/LTS - look at the graph.
(So if you can wait for 12.04 LTS, due at the end of April, good for you.)
Otherwise, the Nginx' PHP repo - ppa:nginx/php5 - is no longer maintained.
You could use Mercer's repo but he himself says not to (I've just updated vpsbible's stackscripts accordingly, hence the know-how) cos it's not maintained.
INSTEAD ... use the ppa:l-mierzwa/lucid-php5 repo with 10.04 and you'll be fine.
add-apt-repository ppa:l-mierzwa/lucid-php5
apt-get update
(Probably it will be fine with 11.04 also if you want to try.)
That gives you PHP 5.3.10. If you want to play with 5.4.0 (which is not recommended unless you're a bug tester) then this ...
add-apt-repository ppa:ondrej/php5
First try to resolve dependency using below PPA but this version is End Of Life, recommended to upgrade php-5.6
sudo add-apt-repository ppa:ondrej/php5-oldstable
sudo apt-get update
Then
sudo add-apt-repository ppa:mc3man/trusty-media
sudo apt-get update
sudo apt-get install ffmpeg ffmpeg-devel
Download php-ffmpeg from http://ffmpeg-php.sourceforge.net/ and extract.
cd ffmpeg-php-<version>
./configure
make
sudo make
Edit php.ini file and add this end of file :
extension=ffmpeg.so
Last week I successfully installed this extension on centos 6
Best Answer
The error means that the package you requested -
php5-fpmis not available in the Ubuntu repositories (or any additional repositories you may have added).php5-fpmis in the "universe" repository that is not enabled by default as it contains software that is not supported by Canonical. You can enable it by starting the "Software Properties" configuration (either though the software center or by launchingsoftware-properties-gtk) and select the second checkbox under "Ubuntu Software" which is helpfully labeled "universe".