SWF fooling HTML to be read as JPEG?

I would like to load a swf as my background image in HTML … is this at all possible?

The reason being, is then I want to have my flash player centralised on the HTML page so that this 2nd swf will be my content. And the 1st acting as a motion applicable background.

Makes sense?
Should be easy, but I guess it’s about fooling HTML into doing what you want it to do …

Help or insight would be mucho appreciated …