SCART connector
Pin Function

Looking at outside of socket

1 Audio out right
2 Audio in right
3 Audio out left
4 Audio ground
5 Blue ground
6 Audio in left
7 Blue in
8 Switching signal
9 Green ground
10 Data line 2
11 Green in
12 Data line 1
13 Red ground

S-video ground

Pin 2
14 Data ground  
15 Red in

S-video chrominance in

Pin 4
16 Fast video blanking  
17 Video out ground

S-video ground

Pin 1
18 Video in ground  
19 Composite video out
20 Composite video in

S-video luminance in

Pin 3
21 Plug shielding