I think you can do that in Adobe Flash, check the file menu and choose 'save as SWF'. Good luck! Hope it works!
DVDVideoSoft is the best tool to convert flv to swf. it also gives you a set of almost all types of most common free converters. small tools but to the point
You may refer to this step by step guide, it will show you how to convert FLV to SWF. http://www.flash-video-soft.com/blog/?p=220 Hope it helps. Contact me if you have any other question about Mac.
and if you have flash installed then you dont need to puy any software. just import the flv . place on main timeline and export the file into swf. thats all
search the net of free swf to flv converter, there are a few free ones that are as good as the paid ones if not better
First Download Snosh software and install it on your PC After install run Snosh then click “import†and add your FLV file Click “Export†After this Click “Browse†to set the path you want to save this SWF file You can rename the SWF file in "Output file name" Click "Export" button to start convert FLV file to SWF file Moreover, Snosh also converts plenty of others formats.
at the macromedia adobe flash, you can open your fla file, and than save it to swf, choose menu -> save as SWF