This package is no longer maintained and is being deprecated
Please try using something like picqer's php barcode generator written in modern PHP and has been actively developed and maintained. It supports a lot more than this and can be installed with composer.
Perhaps the biggest issue I encountered when creating an inventory management system for a client was the fact that there was no unified framework for barcode generation in PHP that was reasonable in price, much less Open Source. I hope to fill this gaping hole in the market today with Barcode Generator for PHP.
In order to facilitate a wide range of usage, the MIT License was adopted for this library.
I have an example index.php on gist. This assumes you have the repo cloned in include/ relative to the this index file: index.php
Some are planned, others are complete.
If you have something to add (maybe a new barcode) or just a bug fix, please send me a pull request and I will be sure to respond or even merge it. I am always looking for help with these projects, so don't be shy.