This is simple shortcode to embed responsive (fixed-ratio) iframes
This is simple shortcode to embed responsive iframe to your post. Iframe will hold the specified ratio when page is rescaled.
[rframe ratio="16x9" src="http://flixel.com/player/snqi608mlq1h98w5p9jy" width="60%" /]
DIV block with specified width is creted. Inside is transparent PNG file with specifed ratio scaled to 100% width and height set to auto. This image will scale the main DIV to size with correct ratio. Embeded IFRAME is then set to fill the wrapper DIV, so it is scaled with the image. Image is created on the fly via PHP and inserted as inline image directly to src attribute of img tag.
Thanks to Masau ( http://jsfiddle.net/Masau/7WRHM/ ) for the "trick".