public static async Task <BitmapSource> GetScreenShot(this MediaElement source, int zoom)
{
var result = (await source.CaptureBitmapAsync()).CreateBitmapSourceFromBitmap();
var renderHeight = (double)source.NaturalVideoHeight;
var renderWidth = (double)source.NaturalVideoWidth;
var zoomedBitmap = new TransformedBitmap(result, new ScaleTransform(zoom, zoom));
var croppedBitmap = new CroppedBitmap(zoomedBitmap, new Int32Rect(
(int)(zoomedBitmap.Width / 2 - renderWidth / 2),
(int)(zoomedBitmap.Height / 2 - renderHeight / 2),
(int)renderWidth,
(int)renderHeight
));
return(croppedBitmap);
}