thanks you all for your replies.
After have read posts on bimmerboard,
i understand and know now the solution to install the reverse camera :
* connect camera power to a switched power (12V + ground)
* connect camera video output to the tv tuner camera video input
* install an automotive relay 12V with :
- reverse light power / ground
- ground / pin 17 of the tv tuner (switch to camera reverse).
I ordered all parts and i'll try to do a clear DIY to confirm all that.
Thanks to all.