as3swf is an actionscript 3 library for handling the SWF file format.

• read SWF from ByteArray
• file header info
• SWF attributes
• SWF metadata
• frame and scene data
• library bitmaps
• symbol names
• DoABC (AS3)
• simple to add support for more tags

I highly recommend downloading the SWF File Format specification from Adobe in addition to this code.