You have not given us much information to work with. Can you tell us whether this switch is a layer 2 only switch or is this a layer 3 capable switch? Can you tell us whether the DVR will be in the same vlan as the cameras?
If the DVR is in the same vlan as the cameras then things are simple. You only need to configure the vlan, assign the appropriate switch ports to the vlan. If they are in the same vlan then the DHCP request from the camera will be received by the DVR and it will be able to offer an IP address to the camera. If the DVR is in a different vlan from the cameras then we need a layer 3 device to forward traffic between the vlans. If the switch is layer 3 capable then it can be handled on the switch. If the switch is layer 2 only then you need some layer 3 device to make this work.