Import FLA?

I have wanted Lightningbeam to be able to import .fla files for a while, as it would make it relatively easy to access old projects. The problem? While the .swf file format is a well known format, the .fla format is virtually undocumented. It is also a binary blob file, which is completely incomprehensible except for some strings of ActionScript. Following is the progress I have made on this.

After some research, I found that there are in fact two completely different types of .fla file: the new CS5 .fla, and the old Flash MX - CS4 .fla. The new format is in fact just a simple zipped folder structure, with attributes in XML. The old one is the undocumented binary blob. Sadly, the vast majority of .fla files in existence are old-type, and not having any new-type files to work with, I decided to start with the old version.
After a good bit of research, I discovered a vital piece of information: Old-style .fla files in fact use the Microsoft Compound Binary File format. That page suggests using 7zip to extract the .fla; however, the Mac/Unix version of 7zip (p7zip) refuses to do so. I suppose it is a special feature compiled into the Windows version.
After some more research, I found a Python module for interacting with MCBF (also apparently called OLE2) files. Installation was painless, so I decided to run some tests on the first .fla I had lying around:

$ python
Python 2.6.1 (r261:67515, Jul  7 2009, 23:51:51) 
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>>> import OleFileIO_PL

>>> assert OleFileIO_PL.isOleFile('exp.fla')

>>> ole = OleFileIO_PL.OleFileIO('exp.fla')

>>> print ole.listdir()

[['Contents'], ['Media 1'], ['Media 2'], ['Media 3'], ['Media 4'], ['Page 1'], ['Symbol 1'], ['Symbol 2'], ['Symbol 3'], ['Symbol 4']]

>>> f = open('Contents.bin', 'w')

>>> f.write(ole.openstream('Contents').read())

>>> f.close()

>>> f = open('Media1.bin', 'w')

>>> f.write(ole.openstream('Media 1').read())

>>> f.close()

>>> f = open('Page1.bin', 'w')

>>> f.write(ole.openstream('Page 1').read())

>>> f.close()

>>> f = open('Symbol1.bin', 'w')

>>> f.write(ole.openstream('Symbol 1').read())

>>> f.close()

I now had four files, acting as representatives for the different types I was likely to encounter. I opened up the 'Contents' file, and found...binary gobbledegook. But it wasn't all gobbledegook; it had some things that were definitely resource links ('Media 1???bottledwater.png???A/Users/greenandsave/Public/Drop_Box/recycling/#1/bottledwater.png??rL??sL???????????????????????2?'), some that were some sort of property list pair (':Quality???4???Vector::FireFox???0???"PublishRNWKProperties::exportAudio???1??? PublishRNWKProperties::speed384K???0???!PublishRNWKProperties::exportSMIL???1???"PublishGifProperties::DitherOption??????-PublishFormatProperties::generatorDefaultName???1???'), and at the end: XML. Not very much though.

<?xml version="1.0" encoding="UTF-16" standalone="no" ?>

<mobileSettings>

  <contentType id="standalonePlayer" name="Standalone Player"/>

  <testDevices/>

</mobileSettings>

The first resource link led me to guess that Media1.bin contained some sort of PNG file. Unfortunately, it wasn't just a png file, as I discovered after changing the extension to .png and trying to open it. Or at least it was either not a pure PNG or it was missing some headers. More research on that to follow.

Abandoning the media for the time being, I opened up Symbol1.bin. It was a good deal smaller, in mostly-pure binary:

?CPicPage?? CPicLayer?? CPicFrame????6b?-Z+?[?@?@4???l???????(??O????<T?

z?0??=??????^?π???\????O4??4?,9?p??8?_f?Z.zF?3u?.??jp?Q;?04W?u??h41?4?????)wC?                                                                              ?e?H??????????Y????????                     ???Layer 1????O?O???

I am guessing that that "Layer 1" in there refers to the name of the layer and not the layer itself, as Flash allows you to rename layers and it would make sense if it stored the names in plain text. This file is small enough that it should be possible to reverse-engineer.

Lastly, I opened up Page1.bin, from which I had no idea what to expect. It starts off with a mixture of binary and XML:

?CPicPage?? CPicLayer?? CPicFrame????????????kD????????

                                                               ???Layer 4?????O??????

CPicBitmap

? M???,???(????a???????????????m?;*?0(?0?m0???????????Ky????????? CPicShape???E@?|>????|????3??????????s??U?>0?0??0?U ???????????????????????

                                                                       ???Layer 1????O?O?????

CPicSpritet -

}???????<component metaDataFetched='true' schemaUrl='' schemaOperation='' sceneRootLabel='Scene 1' oldCopiedComponentPath='1'>

</component>

?? ???O??????m

}???????<component metaDataFetched='true' schemaUrl='' schemaOperation='' sceneRootLabel='Scene 1' oldCopiedComponentPath='7'>

</component>

And then there are about 8 KB of mostly blank spaces and newlines, with one character per line. A sample:

   ?

    K

     ?

      X

       !

        X

         5

          X

           5

            X

             X

              0

               ?

                ?

I have no idea what it indicates.

Finally, it ends with more binary/XML:

}???????<component metaDataFetched='true' schemaUrl='' schemaOperation='' sceneRootLabel='Scene 1' oldCopiedComponentPath='6'>

</component>

????????????????????

                    ???Layer 2?????3???? ????$????????????1???stop();??????~?????????????'?<Y?P??<8H???q8o?Z<??V??<V?T?$?8???q

                                                     ??q???%?P?????????????}???stop();?????

           ???Layer 3??????O???

So, to wrap this up: The .fla file format is quite complicated. But it has a structure, and I believe I can recover many attributes from it. The format of the "Media X" files is something I need to try and find, which I will try by comparing them with the original images.

Is FLA import coming to Lightningbeam? Probably, but not right away.