Duke has released his Imperium solo which is an adaptator to connect USB joysticks (PS4, Xbox One...) or mouses on a standard joystick port for Amstrad CPC. It will be available for other computers later thanks to an update done with the USB port (ZX Spectrum, C64, Amiga et Atari ST).
He will soon start to ship the pre-orders, if you want one it is time to order one but you will have to wait for all pre-orders to be shipped first. I have ordered two adaptators myself.
Check Duke's site about Imperium Solo.
The split cable you see in the video to power the CPC and the adaptator is included with the adaptator for the price of 15 euros, add shipping and paypal cost too.