How to get game resolution from PHP or where to find width and height in hexa code in Unity file format?

Hi, I am owner of game portal with online games, and I would like to implement upload for Unity games as well (now we have Flash and Shockwave).

Is there any way in PHP, how to detect game width and height from file? For flash we are using:

 list($width, $height, $type, $attributes) = getimagesize($swf_file);

If there isn'te fuction in PHP, I need decode HEXA values from Unity3D file, to get WIDTH and HEIGHT. Any clue where to find it? Is there some unity file specification, that I can use to decode file and automate upload in our administration as much as possible.