S-Video to Composite video adapter - распиновка

You may connect pin 4 to ground, pin 3 to rca center pin, extra 2 wires (ground and svideo aren't used), or use following scheme with capacitor:  

Y-ground------------------+
                          +---------- RCA/composite ground
C-ground------------------+

Y-------------------------+
                          +--------- RCA/composite video
C------------||-----------+
            470pF

This circuit works in practice quite well even though the circuit operation is not ideal. This means that impedances and signal levels not matched exactly right, but near enough to work accetably. The picture quality you get from this circuit is is good, but not as good as with best possible composite video output circuitry.

Notes:  Larger capacitor values will also work, but cause picture to become softer.