It appears that most SWF files, if not all are actually swf "archives" containing compressed versions of themselves. I have seen that you can extract the file using a few tools
$ flasm -x player.swf
Flasm configuration file flasm.ini not found, using default values
player.swf successfully decompressed, 206239 bytes
$ 7z x player.swf
7-Zip [64] 9.20 Copyright (c) 1999-2010 Igor Pavlov 2010-11-18
Processing archive: player.swf
Extracting player~.swf
Everything is Ok
Size: 206239
Compressed: 106427
However I was hoping to extract from these using something a little more "conventional", e.g. tar or gzip