Samsung s5 mini - delock cable mouse / keyboard not working I am using a simple delock cable which I ordered on amazon:
Delock Kabel Micro USB Typ-B Stecker gewinkelt > USB 2.0-A Buchse OTG 11 cm

Question: When connecting Mouse/Keyboard through the cable to my Galaxy S5 Mini, it does not work. Am I missing something? or the cable is not working?

P.S: Every video on the web shows that you simply connect it via the cable and thats it.
OTG needs to be supported at the kernel level and you device does not appear to have that with stock kernel as you can see from cursory Google search. 

Samsung S5 mini supports Gamepad through OTG? offers a way of flashing a custom kernel to override this limitation pointing to a XDA thread. You would need root to attempt this

Perhaps some videos which claim OTG support have this kernel flashed or custom ROM enabling this.