[ihryjfbd]

A SWF isn't always a simple container file like FLV, in the majority of cases it works as a browser media player plugin / applet to play external mp4 files etc via a given url string which can be found decompiling the swf and looking at it's source or sniffing traffic from http / tcp or in the case of live streams rtmp / rtsp.
SWF is old and should be a dead format in the next three years in favour of html5, Adobe have already abandoned it.