How do I find the natural size/dimensions of a Flash SWF file?

I made script to detect dimensions of remote swf and print embed code of file.

http://www.igrice-tigrice.com/flash-dimensions.php

I was wondering how to get this myself last night. Didn't find anything on google, but then I remembered that PHP's getimagesize works on swf movies:

<?php
    $file = "YOUR_FILE.swf";
    $info = getimagesize($file);
    $width = $info[0];
    $height = $info[1];
    print "{$width}x{$height}\n";
?>

After years I finally found a little tool that does exactly one thing: Displaying the height and width of a flash file. I cannot believe that Adobe never realized that knowing the size of a flash program is important.

Here you go: https://github.com/q2apro/swfinfo/raw/master/swfinfo.swf

I could not find the original source, please credit the developer if you know about. Thanks.