Flash (.swf) File Format Explained

by bkenwright@xbdev.net

The swf file format if very popular these days, as you can hardly visit a web page without having some sort of advert or effect or even mini game displayed in your web browser.  Its also used in a variety of other places, such as in the game industry and windows apps.  As it allows you to display great graphics which animate, showing cool menu intro's, ambients, and outro's...you can mix in fonts etc, and its size is relatively small.  So you can open up macromedia and do a nice little bit of graphics, and then use your swf importer to load it up in your app or browser!  Easy as that.

Now this format isnt' for the weak hearted!  Its a monster!  Its got all sorts going on in there, so that it does as much as possibly, and is packed as small as possible.  Its got a bigantua amount of information even in the simplest file, including jpg images, animations, fonts, matrices.....it can use compression, and it aligns lots of its data bit by bit (not byte aligned)....

But well I'll give you the low down, and give you a kick start onto the road of writing your own swf file parser!

    o - Introduction, basics!

    o - Compression!..zlib - show me those bytes!

    o - My god! Its a monster (dump all tag names)

    o - Jpg Tag - we can look at the pretty pictures

    o - Its contained!

    o - Displaying more than text!

Advanced.

    o - ActionScript byte code inside SWF.