If a video feed is approved and active, this returns the size in pixels of the feed from the device (which may not be the same size as the object in the layout). If no feed is active then 0 is returned.
It seems that the source always have a resolution of 640x480 which is very small and not a good aspect ratio. Also nearly every camera supports HD or at least 720p.
Is there any way to change this or do i have to upload,crop and download the picture again to get a useable aspect ratio?