The TAAS compiler is different from the ActionScript compiler since its input is not ActionScript source code but already compiled SWF or SWC files. Just like the haXe compiler can output AS3 instead of a SWF the TAAS compiler can do the same.
Now if you add one and one together you see that the TAAS compiler can be used as a very strong decompiler. My own tests have shown that it will work flawlessly where other commercial decompilers output rubbish. Since the compiler behaves like the Flash Player it will “execute” the bytecode in order to parse it which means it has a very highlevel understanding of the structure inside the SWF.
The only question is now what to do with the source code. I wrote the decompiler for my session at FOTB to show much easier how the optimizations behave. It is also a great tool to debug errors. But should it be opened or not?
To take it one step further one might also be able to write an obfuscator using the TAAS compiler. In my opinion it would be cool to have a strong decompiler and obfuscator, both being open source. We might also add an option to protect SWFs from the decompiler by adding something to the SWF metadata for instance. Of course this is just a simple rule which could be removed by someone once the code is open. What do you think?
Another spinoff from my current library to optimize SWF/SWC files. Reducer is a tool that will make SWF and SWC files significantly smaller. There is currently a huge problem with filesizes. If you use the [Embed] tag with PNG images they are not compressed at all. For the Hobnox AudioTool we have been using the Flash IDE to export all graphics so that they are smaller which was a pain.
Now with Reducer you are safe to use [Embed] and then run the tool afterwards. It will compress all lossless images and make them lossy. But usually a PNG can be compressed at 100% JPEG quality and you will still safe a lot of data.
Note: You will not loose alpha transparency when using Reducer. The SWF file format allows us to use a special compression where a PNG gets split up into its color and alpha channels. The color channels are encoded using the traditional JPEG algorithm with adjustable quality while the alpha channel is handled seperately. Transparency is always stored in a lossless fashion which means even with a low JPEG quality you will not get any compression artifacts for the alpha channel.
Update: Reducer is now open source!
Published on
Sep 5, 2008 in
Flash, as3 and projects.
Tags: ant, audiotool, compc, java, mxmlc, swc, swf, xml, xsl.
Last night I spent about 9 hours writing a build script for the AudioTool allowing us to compile each plugin into its own SWF container. I think it is the first time a Flash project is taking more than 5 minutes for me to compile completly.
I figured out that it is definitly not easy to handle the mxmlc or compc in a way we needed it to be. The point is that we have for each plugin three modules A, B, C and a library D. A depends on D. B depends on A and D. C depends on A, B and D. Now to make it even more complex we have A, B, C and D in one project so that developing in this environment stays still simple. The solution to compile all modules in a way we need them to be was first generating unique entry points for the SWF files because we do not want to work with SWC libraries (or the SWF inside the SWC package). After having the unique entry points we compile D (and its dependencies as well) without including the source of A, B or C. Afterwards we can compile A. But B is dependent on A so we have to compile a SWF for A and then a SWC for A so B can link to A as an external library. C is also analog to this but needs B as a library as well. In the end it was 5am and I was happy to have the complete build working which generates a lot of SWF files and SWC libraries.
Since it is very hard to configure Ant for this (I was using XSL in the beginning for automated code generation) I started developing my own Ant tasks. I have to say that it is really simple and saved us hours of work. We have now one single XML file containing the dependencies and the Ant task will do the rest (code generation, compile tasks, etc.).
