Svideo on PSX

[Alex4]

Ok, here the scoop. I am going to add a permanent female s-video plug to my PSone. I have looked at the pin-out  here http://www.gamesx.com/avpinouts/psxav.htm The Y and C connections are obvious. But S-video requires 2 grounds. Anyone know where I would hook these grounds up to?  :unsure:  

[NFG]

Ground is ground.  Hook them up to ground.