A while back (like around 1999) I wrote a set of tools for Flash animations.
One of the tools is swf_dump
which can be used to extract objects (i.e. write the objects in a form of script that sswf can nearly recompile...)
The tool also allows for extracting images that are inline (not downloaded dynamically by the flash animation, if so, anyway, you could as well download those images manually, you'd need the URL, though.)
The command line you can use is:
swf_dump -d my-animation.swf
Then your current folder will be littered with all the images that were found in the flash file. It extracts JPEGs and PNGs. The source can be compressed (SWF or CWF are supported.)
Now, you're on your own to compile that thing... The project is here and is in great need of updating (but Flash is kind of going out too...)
https://sourceforge.net/projects/sswf/