If you are looking for the decompiler itself, visit https://github.com/jindrapetrik/jpexs-decompiler
NEW : We have got a new blog where we post some interesting SWF internals info.

#1806 Addition of CLI -replace option to update bounds for shapes
Author:
Zavar

Date created:
Type: feature
Visibility: Everybody
Assigned to:
Labels: CommandlineImportShapes
State: closed 

Would it be possible to add an option to the CLI -replace command to "update bounds" for
shapefiles that are being replaced? This function is available in the GUI, see attached
screenshot, can it be made available via the CLI?

It's already implemented in the commandline.
The flag name is "nofill". It's not very clear that it's the update bounds feature.
So the commandline would be something like:
java -jar ffdec.jar -replace infile.swf outfile.swf 10 shape10.svg nofill
State: new→upgraded
State: upgraded→closed