This is the gold standard. It allows you to view and edit ActionScript 1, 2, and 3 code, export shapes as SVGs, extract audio (MP3/WAV), and completely rebuild the SWF back into an editable .fla file.
Once you have the internal movie file, you need specialized software to read the code (Lingo for Director or ActionScript for Flash). macromedia projector exe decompiler
This comprehensive guide explores how Macromedia Projector files function and details the exact methodology for decompiling them to recover your original source assets. Understanding Macromedia Projector Architecture This is the gold standard