Rounded Corners MediaElement

so I was working on a new media player for Crossfader and wanted the media element in the new wizbang super tile to be able to form fit as in have roundy corners... I swear I spent hours trying to make this work and I guess had a brain block on this and thanks to Jobi pointing out the obvious the solution looks like this:

<mediaelement width="0" name="ThisMediaElement" height="0" stretch="Uniform" source="http://localhost:36825/Seiryu.wmv" balance="5" volume="0" autoplay="True" downloadprogresschanged="ThisMediaElement_DownloadProgressChanged">
<rectangle width="Auto" name="ControlBack" fill="Black" radiusy="30" radiusx="30" height="Auto">
<rectangle width="Auto" radiusy="30" radiusx="30" height="Auto">
<rectangle.fill>
<videobrush stretch="Uniform" sourcename="ThisMediaElement">
</rectangle.fill>
<rectangle.stroke>
<lineargradientbrush endpoint="0.972438,1.14352" startpoint="0.972438,0.000225328">
<gradientstop offset="0" color="#FF848484">
<gradientstop offset="1" color="#FF000000">
</lineargradientbrush>
</rectangle.stroke>
</rectangle>

seemed like the obvious solution but some how missed it...