Connecting single PoE Hikvision IP camera

Hi everybody

i have bought one hikvision ip poe camera, the model is ds-2cd1021-i

i want to make it working with normal usual power adapter 12volts 3a

the end on camera side is rj-45 connector with all 8 pins ( B type ) and the on the other

side is rj-45 connector with 4 pins only orange and green as usual need for network to work

and the spare pins brown (7,8) pair and blue pair (4,5)are to give power to camera

is it possible to connect them to power adapter brown pair as negative...

Connecting single PoE Hikvision IP camera