Cameras with both high and low def streams

[BiloxiGeek]

My current zm install is 1.27, getting ready to reinstall from scratch on SciLinux 7 and zm 1.28. All my cameras have one low definition stream and one high definition stream.

Currently I do motion detection on the low def stream, and link the high def to that, so when an event occurs both streams get recorded. I'm curious if anyone has tested this method versus just ignoring the low def stream and doing everything with the high def stream.

How big is the difference in motion detection on a 320x176 image streaming at 5 fps compared to 1920x1080 at 5 fps?

I plan to start setting up the new install with just the high def streams and do some eyeball comparison of how it's performing versus my current setup but was hoping someone here had already worked through this question and might provide their experience and advice.

[river100]

I must be doing it wrong after reading all the posts about motion detection on
the low def' stream. I have always done the detection on the main stream without
a problem. Most systems running at 10 to 15 fps per camera, and resolutions
from 720 to 1080.
My CPU usage has never gone too high doing detection.
Then again most have an average of 6 cameras with dual quad cores and 8 GB ram.
The only issues I've had is hard drive management when the purge kicks in.

I have one running on ESXi, I'm going to try your method and check the results.
It only has one HD IP cam but I can check the long term results with XYMON.

[BiloxiGeek]

Next chance I get I'll be doing a fresh install of SL7 and zm 1.28.1 on that server. I plan to start by only setting up the high def streams and see how that goes. I should have good historical cpu and memory usage from check_mk to get a look at how it changes.

I just need a day where I don't have painting/yardwork/honey-do list things keeping me from hiding out in the workshop for a few hours.

[nkdj]

Hi guys! I'm new to zoneminder. I also have dual stream cameras, but how do I set the low-res stream for motion detection, while the high-res for recording? please help.

[BiloxiGeek]

Got my SciLinux 7.0 install done last weekend and set up my IP cameras using only the high definition streams. So far it looks like only doing the one hidef stream is about the same as doing both streams. The system works a bit harder handling motion detection on the larger images, but doesn't have to manage two streams. For my situation apparently it's a wash. There's not enough difference between the two to make one a clearly better choice.

The one thing I do miss by not having the lowdef streams working is the montage of lowdef streams. When viewing remotely getting a montage of just the lowdef was quick and easy. Getting the montage using hidef streams is a lot of bandwidth and not as easy to view when I'm on my iPad or iPhone.

So since there's not an appreciable difference I think I'm gonna go back to the previous setup and add in the lowdef streams to do modect then link the hidef streams to those.

[BiloxiGeek]

Hi guys! I'm new to zoneminder. I also have dual stream cameras, but how do I set the low-res stream for motion detection, while the high-res for recording? please help.

Set up the lowdef stream to be modect, get it working well for you as far as the zones, frame rates, sensitivity etc go. Then define the hidef stream as a nodect monitor and link it to the lowdef stream. When the lowdef stream is in alarm or alert and starts recording the HiDef stream will be recording as well. Any time motion detection starts a recording both streams will be recorded and you'll get two separate events.

[nkdj]

Thanks for the reply. It's not the best solution I was hoping for, though. Anyway, I'll give it a try.

[carcachute]

You could also do what I'm doing, which is to record hi-def video 24/7 directly to disk files and rotate out the oldest ones periodically via a script. On my system this happens entirely outside ZoneMinder.

I then use ZoneMinder strictly to monitor the low-def streams. If there is an event, I log into ZM and look at the low-def recording, and if it's interesting, I pull the hi-def video file for the 15-minute time block of interest.

This requires a lot of disk if you want to keep hi-def recordings going back, say, a full week, but the CPU load is negligible. I use an old Intel Atom box and the CPU load is about 15% with 2 2MP cameras and one 3MP camera. That's 13% for ZoneMinder and 2% for the background recording to disk.

[nkdj]

Hi carcachute,

Thanks for the suggestion. I also have a small PC, a Gigabyte Brix running on Celeron n2807. I posted my config here. Basically I have followed BiloxiGeek's suggestion as I am not very familiar with scripting.

May I ask what are the fps of your cameras? My configuration seem to consume a lot of cpu resources. I want to optimize it but at the same time capture/record at highest possible fps for motion.

Regards,
Neil

[carcachute]

Hi carcachute,

Thanks for the suggestion. I also have a small PC, a Gigabyte Brix running on Celeron n2807. I posted my config here. Basically I have followed BiloxiGeek's suggestion as I am not very familiar with scripting.

May I ask what are the fps of your cameras? My configuration seem to consume a lot of cpu resources. I want to optimize it but at the same time capture/record at highest possible fps for motion.

Neil, here is my configuration.

Camera 1:

• main stream: 2058 x 1536, 10fps, 3072 Kbps constant, I frame interval 50
• substream: 640 x 480, 8fps, quality medium, 512 Kbps max, MJPEG

Camera 2:

• main stream: 1920 x 1080, 10fps, 2048 Kbps constant, I frame interval 50
• substream: 704 x 480, 8fps, quality medium, 512 Kbps max, MJPEG

Camera 3 (DCS-2230):
Two profiles active (can do 3)

• Profile 1: 1920 x 1080, H.264, 15 fps maximum, 2M constant bit rate
• Profile 2: 640 x 360, 7 fps maximum (there is no 8fps or 10fps setting), quality standard (lowest), MJPEG

Of course, the frame rates are set only in the camera and not in ZoneMinder. Also, ZoneMinder is monitoring only the substreams. 8fps is good enough for motion detection in my home application. The main streams could easily do 15 or 30 fps, because I am recording straight to disk outside ZM which uses almost no CPU. The issue is that I would need a much larger hard disk to preserve image quality with higher frame rate, and high frame rate isn't as important to me as image quality. I use a 750 GB WD Black laptop hard drive which can hold about one week of recordings with enough room leftover for ZM storage.

[darmach]

Guys, I configured my substream as MODECT monitor, and added main stream as NODECT, linked to substream monitor. I defined zone on substream monitor, both are set to record x264 passtrough.

However events are generated only for MODECT (substream one). I don't see any events triggered on main substream monitor. What might I be dooing wrong?