Adding a page with a PHP video gallery

I have a page with a video gallery written in PHP/HTML/CSS that pulls videos and thumbnails from subfolders and launches a page with a flash player to show them. There is user input on the viewer page that needs to be stored in/retrieved from a database. I need to integrate this code into a WordPress site, but I can’t figure out from the docs how to place this stuff in the content section. Is this a plugin, or just a page? If it is a plugin, is it hooked in through an action or a template tag?