While we are on the IP / NVR topic, I have a sort of basic question. Tell me if I’m right about this:
First a more background about my system and what I’m basing my knowledge or assumptions on.
I have a Dahua branded system set up by an installer but I’m needing to add cameras and will have to get NVR with more capability. My current Dahua 8 ch NVR is set up to (apparently) only record a ‘high res’ stream from each of 5 cameras and I get about ten days of looped data from the 5 cameras on a 4TB drive. I’ve been told that the 320 KBPS is the max data rate into the NVR. I need about 5 more cameras and plan on getting the cameras and a new NVR. I was told that one option would be to add another NVR and keep the old one and use it for redundancy or perhaps secondary stream storage with more days storage as a result of low res storage. I am understanding that a second NVR would just capture one stream and the old one would do the same. In the same way, I guess I could get a smaller NVR and use it for the new cameras separately.
I might keep the old one on line for low res. Makes sense. But I would buy a fully capable larger, 16 ch unit to handle the new configuration for all cameras.
My understanding of what’s going on with the system is this:
IP camera puts out one or more (I’ve seen specs that show 3 streams on one camera) real time video data streams, compressed by the stated codec as per the specs. There is typically a high and low data rate stream. It looks like the camera (higher end Dahua and others I presume) may be programmed for different data rates on the streams but I’m not certain about that. That would be the ideal situation, for the user to be able to strike a compromise between image quality and data load / system storage and bandwidth limitations. For ex, full res on a 4K camera seems to be almost a GB . . . not practical or even possible to do but looks like maybe it’s programmable through perhaps a Dahua app on the network (or remotely?) Here is a reference to a 4K Dahua dome camera I’m looking at that does 3 streams.
And here is a capture of part of the same document
Would I be correct in assuming I could program this cam to custom data rate specs for each ‘stream’? I’m guessing that streams could be turned on or off (?) Why clutter the network with unwanted data. Another reason I want to know about programming the data rate is this - their 8K dome cam is way more than I need or want to manage in terms of data. BUT . . . it’s only $40 more. If I could simply program it to a lower data rate and / or just use the lesser pixel options then that would leave a possibility for upgrading the video quality if I should ever want to sample at a higher res or data rate?
And it looks like cameras do a lot on their own as well. There is stuff in the specs about motion zones, trip wires, privacy zones. I would have thought those were implemented either during stream acquisition and storage by the NVR or at ‘playback’ according to the user’s criteria.
So I guess the various streams are always just flooding the network and it’s up to the NVR to capture what it wants? Is this about right? I know this is basic.
BTW, @StanSimmons mentioned this NVR and I see it states a “160Mb Bandwidth 16 Built-in PoE”
Is that the total incoming BW from all cameras? The one I have is a couple of years old and I think its BW is 320K. Would 160 be a limitation? in a 16 camera system?