convert ~1000 swf to jpg / png / gif - windows

Question

I've got around 1000 swf (I even got the fla's) files I'd need to convert to any image (jpg, gif, png ...) with the only solution to save the fla as image at the moment. Not helpful with that amount.
Is there any command line tool I'd be able to use? I'm on Windows 7 or Ubuntu.
Already searched for a bunch of tools but they only convert one file at a time or have to be purchased.
Sidenote: the swf's aren't animated, just static pictures

Answer 1

Found a solution and want to share it:
I used sfwtools, which I installed with:
sudo add-apt-repository ppa:guilhem-fr/swftools
sudo apt-get update
sudo apt-get install swftools
Created a bash script using gedit (let's say it's called convertswf)
#!/bin/bash
for file in *.swf;
do
swfrender "$file" -o "$file.png"
done
or use this extended version if you have swf files in subfolders:
#!/bin/bash
for file in $(find "path/to/directory" -name '*.swf');
do
swfrender "$file" -o "$file.png"
done
finally did:
chmod +x convertswf
./convertswf
hope it helps!