[prensing]

You can also put start up code in /etc/rc.local. That will run at the end of boot. But as others have said, you might need to wait on the camera to be up.

However you start it, I suggest you put that code into a bash script (or similar) so that all the logic is in one place. So something like:
/usr/local/sbin/startGRIP
If you put it in /etc/rc.local, end the line with "&" so that it spawns a separate process and does not keep the boot waiting.