ONSSI Recording Times

Hello,

We are currently using ONSSI to record multiple cameras at our institution. We have most of these cameras set to record only when they have motion in the frame. We have run into a couple issues when we don’t have enough lead time recorded before the motion event starts. Does anyone have recommendations for timing settings before and after motion events? An example would be to start recording 3 seconds before and 1 second after the camera detects motion.

Thanks


Michael, Are you doing the video motion detection on the server or camera side?

Michael,

I am a technical trainer for OnSSI.

If you are using server-side motion, pre-recording and post-recording buffers can be set up to be whatever you want them to be on the recorder. However, if you are missing that much of the beginning of any motion event you might want to reinvestigate your motion sensitivity settings.

A combination of both of these things will usually solve the issue you are reporting.

Assuming server side VMD, ONSSI also allows you to specify a frame rate during non-motion that you can set low, like 1 FPS, and then speed up on motion to 15 FPS. Then you don't get stuck wishing you could go back earlier, though at the cost of some added disk space.

Assuming server side VMD, ONSSI also allows you to specify a frame rate during non-motion that you can set low, like 1 FPS, and then speed up on motion to 15 FPS.

You can not mingle the two - VMD and 'Speed Up' (as it's called on the recorder) are never used together.

Speed Up is used to save storage when you record full time (either by choice or by mandate). You set the camera to record at 1FPS (any more is dumb - think about it - frame rate doesn't matter when there is no motion) then 'speeds up' to whatever FPS you want when motion occurs.

So the logic is that you reap the benefits of 'VMD-like' lower storage while maintaining a complete database of everything that happens (and doesn't happen*)

*The only way to prove something didn't happen is to have video recording of it not happening.

You can not mingle the two - VMD and 'Speed Up' (as it's called on the recorder) are never used together.

IMHO, Speedup is typically used with VMD*. And in this case its necessary, else how does the recorder know when to 'speedup'? Right under the Enable Speedup checkbox is the On Motion one, no?

Obviously you know ONSSI far better than I and I am always excited to learn something new, so don't pull your punches!

*Assuming VMD = Video Motion Detection, i.e. the software component (analytic) which determines that motion has occurred by looking for changes in a video stream's scene that exceed user set thresholds.

Sorry, I misspoke above. I should not have said 'you can not mingle the two'. Because you can.

What I should have said was 'you shouldn't mingle the two because it is dumb and makes no logical sense'. Because it is and it doesn't. :)

Speed Up makes a lot of sense when you want/have to record full time - for the reasons I've already explained above.

However, if you are recording on motion already (i.e. not recording anything unless there is motion) what exactly would you be 'speeding up'? You aren't recording anything until motion begins anyway.

Example: If you set your FPS at 10 and record on motion, then set Speed Up to increase your FPS to 30 on motion, guess how many images you will record at 10FPS?

ZERO - they will all be 30FPS.

Marty, my suggestion was to record during non-motion and motion, i.e. continuously, just at different frame rates. I thought it was obvious that when I said set the frame rate to 1 FPS during non-motion I meant record 1 FPS. That's why I said the trade-off is you would need more storage.

Take a look again at what I said but let me first insert one new sentence in bold

Change image storage setting to Record Always. Assuming server side VMD, ONSSI also allows you to specify a frame rate during non-motion that you can set low, like 1 FPS, and then speed up on motion to 15 FPS. Then you don't get stuck wishing you could go back earlier, though at the cost of some added disk space.

Are you O.K. with it now?

I would think its totally clear now to you, except for the fact that there is clear and beneficial mingling going on, VMD and Speedup, which you are insisting cannot be.

Do you think that VMD means "record only on motion?". I don't. IMHO, it means detect motion, and then once detected, presumably one would take some action, change frame rate, send alarm i/o, start recording...

VMD is the analytic, Speedup is the action.

Thanks for clarifying - the addition of the new sentence makes it totally clear to me now. I'm glad we are both on the same page regarding the use of Speed Up only when recording always. :)

"Do you think that VMD means "record only on motion?". I don't. IMHO, it means detect motion, and then once detected, presumably one would take some action, change frame rate, send alarm i/o, start recording..."

I do not disagree with assessment of what VMD is, but I would maintain that generally when someone says VMD, they mean 'record on motion'. This is what led to my confusion regarding your previous posts in this string. :)

I agree we were talking about the same thing. When you used the term 'VMD-like', I suspected that we were using VMD in different ways, that's why in my first response, I had included my definition of VMD for you to object to then, if need be... :)

I didn't mean to sidetrack what could have been a rather concise thread on motion detection options. I only brought it up since no one had, and with disk storage costs dropping, it may be the best option, or its at least the surest and least time-consuming way to insure you record the whole event.

Back on topic, there is one anomaly that I have seen with speedup, though I don't think the problem lies with ONSSI necessarily. Have you ever noticed that sometimes, probably depending on the camera, that the framerate decreases for a beat before increasing to the right FPS?

Probably not noticable when going from 1 FPS, but when going from 5 FPS to 15, there can be a pause (as a new stream is created?). Obviously it sucks to lose frames at the moment you want to get more, but maybe as cameras have gotten more powerful this latency has been eliminated/diminished. Have you seen this effect?

I have not seen that before.... but then again, I have never set my regular recording FPS any higher than 1 because that makes no sense to me.

Now, if the recorder actually does drop frame rate briefly just as motion first engages - before it gets to the Speed Up frame rate - then maybe you could use that knowledge to game the machine into giving you a minimally acceptable FPS even then. i.e. set the regular FPS at 10 to achieve at least a minimum of ~5FPS for the first images before the FPS jumps to Speed Up rate.

With that said, I would investigate the purported delay (maybe you are right and the new stream being created does that; maybe its a CPU load thing - I don't know) before I would recommend a customer waste storage recording a 10FPS stream that looks exactly the same as a 1FPS stream for periods of time when there is no motion.

Michael, has your original question been answered?

Rukmini, Marty, no more comments until / unless Michael responds.

Yes these replies have been very helpful. We are doing our VMD on the server side to answer one of the first questions asked. We will be reevaluating our setup to see if any of these changes will be helpful. Thanks again for all the responses.