We have several cameras in our office for demo pruposes. I would like to record them all to two seperate systems for showing to clients. I know there is the obvious issue of two different systems sending configurations to the camera (frame rate, resolution, etc.), but I think we can manage that. Are there any issues with streaming or recording these to two different systems?
Streaming A Camera To Multiple Vmses?
You might run into a few weird issues.
This could overload the camera and cause frame rate to drop or other quality issues. This is especially a concern with low end cameras and speciality cameras (like the Arecont multi-imagers that are processor constrained to begin with).
Additionally, if 2 VMSes are simultaneously connected to a camera, they might change low level settings of the camera that could impact the other VMS.
This comes up often so I'll chime in. In the good old days of analog, your only concern was properly terminating.
Let's talk about IP because the assumption is if it can provide multple streams then it should be no problem. Not a good assumption.
If you pull RTSP video streams from the camera, and it's capable of it there should be no problem but you will have no control over the camera. This doesn't work well for PTZ's.
If you connect via ONVIF / SDK / API / CGI then you will likely have an issue because MOST (not all) VMS or NVR products actually query the camera at the time you add it and after that. They will typically load the values in their database for the camera at that time. A prime example would be NVR/DVR's that use NTP for time regulation and update the camera routinely.
Anyway....you have VMS #1 setting parameters at 30IPS - 1080p - 6MBPS using the CGI or SDK commands.
Meanwhile VMS #2 is connecting using ONVIF Profile S and sets the camera at 15IPS - 720p - 8.1MBPS and happens to not time sync correctly.
You end up trying to level a 3 legged stool if you know what I mean.
I'm not saying there isn't a way, it's just not as easy as it seems.
I've been messing around also with multi-streaming/recording and agree there is some strange, idiosyncratic behavior, probably involving camera-side race conditions. This makes it extremely difficult to predict how stable a configuration actually is.
Everything seems fine but then connect to the cameras in a different order and everything can go haywire. Sometimes it seems it's actually better to have two dissimilar VMSes or NVRs, because of they way they interact.
In your example, Greg, can you explain more about what the undesired behavior is? Does the frame-rate change on both cameras to 15 FPS or does the time on the camera get set wrong, or something else?
BTW -Unlike a four-legged stool, a three-legged stool never wobbles, even on uneven surfaces. ;)
My experience: whith several VMS/NVR, it's most of the time a mess
Most VMS push their settings to cameras: Resolutions, Fps, Compression and sometimes CBR or VBR, but also ... PTZ Home positions...and also Private masking or motion areas
So 2 VMS will try to push their own settings and will spend time to stop, set, restart streams when detecting an other system changed their owns.
Very few brands, like Axis accept that several VMS create their own profiles (with different profils names) , so can remote monitor independant settings from the same cameras.
Let's add that camera also saturate when you ask too many streams, and as most VMS monitor 2 streams per camera (Rec/view)... it's becoming easy to saturate camera CPU
Very few IP cameras got a CPU indicator (Bosch only from what I know at the time being)
What are you trying to show with the two vms? If camera control is not part of your need, and your vms supports it, just use an rtsp url for the video stream only without control. Again, if the camera can support two full rate/resolution streams you should be good. And then there is multicast...if supported.
We are seeing and more need for multicast viewing. Particularly in traffic where the video is shared with many users. VLC as a client.
Just some simple thoughts
In theory, you can use VLC to act as a proxy: receive the stream from the camera (rtsp only) and serve it to multiple VMSes. In the VMS, you gonna need to use the "RTSP Generic driver", if available. Note that you won't be able to use PTZ this way.
yo, neither local dewarping, neither dry contact, audio out... all TCP unicast commands
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