Dahua NVR - Facedetection "AI by Camera" not working

S

Sasse

n3wb
Oct 8, 2025
13
1
Germany
Hi everyone,

I have a DHI-NVR4208-8P-EI and connected a DH-SD1A404DB-GNY to it.
The camera has AI features like Facedetection available.

Both on camera and on NVR it is activated (AI by camera on NVR).
In the camera menu I can only activate "Global" face detection, the PTZ position specific face detection is greyed out as long as I use IVS for this PTZ position.

But despite of that, it doesn't seem to work. I don't get any face-events reported on the NVR/App and also no face thumbnails are stored.
AI by device was working, when I tested it, but I want to use it for the camera on another channel which doesn't habe it built in.

Has someone any clue what could go wrong? Any settings I might have missed on camera or NVR?

Thanks!
 
Last edited:
Okay, I'm one step closer.
The problem is definitely on camera side.
The camera is detecting faces (and transmitting to NVR) when IVS is disabled.
But why is that? There is not a single information about that limitation within the UI.
And why have a setting that face detection is enabled globally together with IVS PTZ specific anyway, if that is not possible?

And I can't active IVS on NVR for this camera, as I would have to deactivate Face Recognition.

That's kind of frustrating.
You buy a camera that can do IVS and FD, therefore you buy a NVR that has only limited AI capabilities, because camera can do it on it's own, so you thought...

Does anyone know why IVS and FD can't work at the same time? Is that actually a hardware limitation or software restriction to make you buy more expensive cameras?
 
Its quite common and has been for years since AI features were introduced to limit the number of AI features that can be enabled at the same time.
Its mostly a horsepower thing with regards to AI features needing a lot more RAM/ROM and FW files that approach
Certainly there is also a price point issue for differentiation of more expensive and capable models.
Dahua's low end gear is often restricted in both features and capabilities such as incoming bandwidth

The higher you go up the feature/price food chain there are cameras that allow multiple AI features to be enabled simultaneously, but still there are limitations.
FD in particular has always been limited with regard to interacting with other AI rules. I would think/guess its very processor intensive
 
Well, that's disappointing but what I expected after my observation.

To be honest, FD is just a nice to have for me, and I wanted to find out what I can do with it, so not a big deal.
But it would be fair if this would be mentioned more clearly that you can't do both at the same time.
Since IVS is way more important, I guess almost everyone will just skip FD.

And that's what I'll do as well, deactivate FD completely and never look back. ;-)
Good I didn't invest more money into more AI features on the NVR.
 
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IF you get face detection working, you shoulf be able to have the camera run face detection and the NVR run Human/Vehicle detection.

And... Some of the NVRs are limited on how much of what can be used, such as no Face and hum/veh. It's one or the other. The higher end NVRs give more AI options.
 
Yes, I think I would have two possibilities.

FD on Cam + IVS on NVR
or
IVS on Cam + FD on NVR

In both cases, I can't run FD on my second camera (on NVR only) as I believe, that NRVs also can't do FD and IVS at the same time, even on different channels.
At least there was a prompt coming up telling me, that AI resources are exceeded or something like that. Especially when also doing face recognition, which is the main reason you would use FD anyway.


My original plan was having FD + IVS on Cam 1 and for Cam 2 IVS on Cam and FD on NVR + FR on NVR ... but that won't be possible
 
Yes, but it's not precise enough.
8 Channel FD by camera + FR by recorder -> check
1 Channel FD by camera + 1 Channel FD by recorder + FR by recorder -> :idk:

And what if I ad IVS to the equation? :cool:

But I don't wanna complain, getting all the necessary information before making the purchase is almost impossible for a beginner.
That's disappointing but also that's what experts for, and Dahua is certainly not a very consumer orientated system.
Paying for an expert was not an option for my private usecase, so I'm happy with my decision to go for the lower end model NVR.
I just can't use the "nice to have" features, but everything else is handled well enough.
 
That is why Dahua doesn't sell to the end user and relies on their business model of providing equipment to their authorized dealers and installers that know the systems.

We as home owners are just fortunate that we can get this stuff on the grey market and have forums like this to help us with questions!
 
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