NCD800 - fine tuning BI settings for reasonable .BVR file size

[Virga]

After a period of being distracted by physical installation, I am circling back to fine-tune settings on a couple of NCD800 cams.

A specific problem to solve is the .BVR file size generated each hour, currently close to 3 GB/hour.

NCD800 by Annke/Hikvision are two-sensor 180-degree cams that work well as overview cameras.
When I had first installed them I had quite a time getting sub-streams to show up in the settings, but I did get that to work and there is a thread on that topic.

For 5442 cams, the file size generated is around 0.25 GB/hour.

With a two-sensor NCD800, the file size will be larger than the 5442, but at close to 3 GB/hour, the size is larger than expected.

I missed something in the settings and would like to clean that up.

Attaching screen shots of cam settings in BI.

What did I miss?

What would be ways to reduce .BVR file size without compromising the stored image quality too much?

 

[wittaj]

Either lower the substream and/or check motion settings - is this thing triggering all the time and thus recording mostly mainstream?

 

[Virga]

These cams rarely trigger, not much happens in their field of view.

 

[wittaj]

The 180s tend to trigger more for shadows given the larger FOV, so I would confirm that it isn't recording mainstream on you and not alerting you for not meeting your criteria?

I had to tone my motion detection way down with a similar field of view. I am only triggered for people, but it is still switching to mainstream for every trigger.

 

[Virga]

Am thinking the way to test your hypothesis would be to turn off motion alerts, initially.
Would the best way to do that be to uncheck "Motion sensor" on the Trigger tab?

Then, to fine tune motion detection, would it come down to the sliders under Motion sensor?
Right now they are at defaults best as I recall.

* Moving shadows of trees when it is windy do trigger

 

[wittaj]

Yeah that would be a good test. Uncheck Motion Sensor and check on the BVR file in an hour. I suspect it will be a lot smaller.

 

[Virga]

I was optimistic and hopeful that turning off Motion Sensor would be a confirmation, but file size is still greater than 2.5 GB/hr over last two hours along the lines of prior pattern when Motion Sensor was on.
I looked over historic alerts and there have only been one or two every 24 hours.
So something else.

 

[wittaj]

Wow that is insane.

Everything looks in order.

If you do a playback can you tell it is substream?

 

[Virga]

By eye, it looks like it is substream because I'm seeing more detail in the live image vs when I roll back to say 15 minutes ago.
I tried several times and came to the same conclusion, though subject to confirmation bias.

What specifically would I do to lower the substream?
I could try an experiment by pushing it real low and see what happens.

 

[wittaj]

Yeah drop it to D1 resolution and 256 bit rate and see what comes back.

If that is high then maybe delete the camera and re-add.

 

[Virga]

Done, now the wait and watch.
Note, only two choices in resolution for substream, the before-change original 1920x536 and after-change 960x272.
Bit rate at 256 is the lowest available from drop-down list 8192, 6144, 4096, 3072, 2048, 1024, 512, 256.

 

[Virga]

The 6 pm file saved at 0.1 GB, vs 2.5 GB or greater for files prior to above substream changes.
So now the question is how much to increase the bit rate, and whether to increase the resolution (only two alternatives for resolution).

@wittaj thank you for your insights and help.