Unstable FPS depending on what cameras active

[pyspilf]

Context:

3 IP cameras using one point-to-point Ubiquiti radio link.

1 camera is a Dahua IPC-HFW2431S-S-S2 (4MP) and the other 2 are cheapo Nivian cameras (5MP) which will be replaced soon with decent cameras.

All cameras running at 15fps, keyframes 15, H264, the Dahua at CBR 6144, the other two around VBR 5120 as they cannot handle any better.

The Ubiquiti link is not saturated. It is running at around 14-16MBps with a capacity of 100MBps+

Issue:

If I run the Dahua alone, the fps is quite stable. If I run all three cameras at the same time, the fps on the Dahua becomes unstable, oscillating between 8 and 24 fps... it's all over the place. The cheapo cameras stay stable...

Additional considerations:

I have other parts of the property running a mix of Dahua / Hikvision cameras on the same types of link (or even worse, as one end is a WIFI access point and the camera end is the Ubiquiti, so not a dedicated point-to-point) and for all of them the fps stay stable for all cameras

Any thoughts?

Could there be something in the network configuration / behaviour of the cheaper cameras that interferes with the stream from the Dahua?

I have tried all sorts of changes in config on the cameras but the problem is still present.

I suppose I could try to move a couple of the other Dahua/Hikvision cameras and temporarily use them in place of the cheapo ones and see if all goes back to normal, but quite a bit of work to move everything around.

 

[wittaj]

Usually when we see FPS fluctuations, it is either the camera itself, a power issue, or a network issue.

In your case, the cheapo cam could be flooding that part of the network with tons of requests maybe trying to phone home and is causing lost packets and it is the Dahua that suffers.

 

[bigredfish]

And because the Dahua is running CBR and the others are VBR, the cheap cams can raise and lower bitrate quite dramatically as the scene changes, effecting the total bandwidth.

 

[pyspilf]

@wittaj @bigredfish thanks! Both of you seem to think that the issue could be around network traffic… I thought so too, but as I mentioned traffic is around 14-16Mbps on a link which is capable of a lot more… I spent a while observing it on the ubiquiti device manager, and it wasn’t really spiking or getting congested…

unless it’s not bandwidth per se but maybe other types of issue like collisions etc but I’m not knowledgeable enough to diagnose that…

I think I will try removing the cheapo cameras and put in two of the others and observe

 

[bigredfish]

Can you download and/or post a small clip from the Dahua? What are you recording it to?

Could well be the actual recording is fine that would show if it’s a network issue vs a camera output issue

 

[pyspilf]

So I had a look at a clip recorded with that camera and it exhibits the same behavior. The fps (I have an overlay to show that) jumps around between 8ish and 20ish and the recording is, of course, choppy.

I checked the rest of my cameras and recordings are stable at around 15fps and smooth.

I am recording direct to disk BVR, only on motion, not 24x7

I am not recording to SSD but to a normal HDD (not the fastest but it's never been a bottleneck even with various cameras triggered at once).

Worth noting perhaps that the substream shows stable at around 15fps even though the main stream jumps around. But of course it's a very small data stream...

I can try and disable the cheapo cameras for a while and let the Dahua be alone and see if recordings also show a stable main stream.

 

[pyspilf]

I was just looking at the camera now, and with the cheap ones disabled it still seemed a little unstable... I wonder whether maybe it's a lot simpler and just a failing camera...

 

[pyspilf]

The link is surely not the issue, as I tried the opposite. Disabled the Dahua and left the two cheap ones on, and they both are stable at 15fps on both main and sub streams

 

[bigredfish]

You’re not running H.265 or have ROI enabled?

 

[pyspilf]

So, all cameras are running H264 to make things easier on the processor. No cameras have ROI enabled.

The particular Dahua camera has Smart Plan enabled and one intrusion zone. I tried disabling to see if that had an effect, but it doesn't.

I have also done a few more changes:

On the cheap cameras, disabled multicast, changed VBR 5120 / VBR 512 to CBR 4096 / CBR 512 as it seems to be the most they can manage for main and sub streams

I tried disabling multicast on the Dahua, but had no discernible effect. All other features (UPNP, Bonjour, DDNS, etc) are disabled, and always have been.

I also rebooted the whole network, WIFI, LAN and Ubiquiti links.

It seems a little more stable now, but still not as good as I think it ought to be.

Over the next few days I will try using some cameras from other spots and making some tests.

It's difficult to isolate an issue like this with so many components / configurations / parameters potentially contributing

Thanks a lot for all your input

If I manage to fix, I will update here with my findings.

 

[Binod Bhandari]

Maybe it's a compatibility thing between the Dahua and your network setup. Have you tweaked the Dahua's network settings? Testing with other Dahua/Hikvision cameras could give a clue.

 

[pyspilf]

Well, I have another 4 Dahuas of the same model, and 3 Hikvision. All are configured the same in terms of network, encoding, etc. All the Ubiquiti links are configured the same too... The throughput on all the links is way below the maximum capacity... I think something is going on with what the cheaper cameras do on the network although they do not have that many settings to change... perhaps the most efficient course of action will be to try swapping some cameras around and seeing what happens...

On one Ubiquiti link I have 1 Dahua and 2 Hikvision cameras, and on the other, 2 Dahua and an older Foscam (soon to be replaced too) and all of them are very stable. This third Ubiquiti link with one Dahua and two cheapo cameras is the one where I see these issues