The correct answer is that thiis is usually installed into /usr/share/php, which, in turn, by default is included in php's innclude_path.

By default it will "just work" as you have listed it above. If it does not:

use dpkg -L php-getid3 to find the location of the ihstallation

Then, you can either:

• Check your php.ini files to ensure that location is specified in include_path
• AND/OR use that location in your require_once statment