While not the best option, you could try compiling gnash yourself and passing the
To do this, I downloaded the latest gnash from http://ftp.gnu.org/pub/gnu/gnash/0.8.10/
tar -xf gnash-0.8.10.tar.gz
Change into the extracted directory
But to do this, you will need basic development tools (GCC, GNU Make) and some libraries like FFMPEG, boost and agg (but you can install these from your distribution, no need to compile yourself, otherwise you would be compiling for a while).
I may have left a few libraries out, but
./configure should tell you if you are missing something.
You can then run
./gui/dump-gnash [options] movie_file.swf.