fullScreenSourceRect for HTML?

In Flash there is option ( fullScreenSourceRect ) to play a specific region in full-screen mode. This is not implemented in HTML target. How easy will be to add that option or is there any other way to do it ? Here is information from Adobe : http://help.adobe.com/en_US/AS2LCR/Flash_10.0/help.html?content=00001538.html

I believe it would happen here:


In theory, the __displayMatrix could be set to scale and position based upon a fullScreenSourceRect property

It would have to be conditional on fullscreen, though