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How-to: How Do You Setup Event Pre & Post Recording for a Hikvision Camera?

To Adjust the smart event pre-record and post-record you need to follow these steps:

1) Log in to the NVR/Camera

2) Go to Configuration > Storage > Schedule Setting > Record Schedule

3) Click the 'Advanced' button at the top right of the record schedule

Screenshot 2021-03-25 at 12.57.51.png

4) Select the duration you want from the pre/post record dropdowns and click OK

Screenshot 2021-03-25 at 12.58.40.png

One thing to be aware of with event pre/post-recording is what Hikvision call a Buffer Zone. The buffer zone is simply a bracket of footage around the current moment in time that is continually recording/erasing, this buffer zone allows you to record only by event but still have access to footage before and after the trigger event without having continuous recording enabled.

The issue is that the buffer zone is limited to around 2-4MB of storage and so the higher your resolution and stream settings the larger the files sizes are and thus the maximum duration of the buffer you can use is limited. So basically an 8MP camera will not be able to have as long pre/post recording durations as a lower-spec 4MP or 2MP model. (unless you reduce the resolution/stream settings of the 8MP camera)

We recommend that to get the longest duration possible from your pre/post recording you should set them to the not limited option to use the full 2-4MB buffer capacity.

(One other thing to be aware of, there is no advantage or disadvantage for pre/post recording when using an NVR. Although the NVR is managing the event recording, each channel on the NVR is still set to the same 2-4MB buffer, the same as the individual cameras. So you would not get more pre/post recording capacity with 1x 8MP than you would with 8 x 8MP cameras on an NVR.)
 

daveb

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(One other thing to be aware of, there is no advantage or disadvantage for pre/post recording when using an NVR. Although the NVR is managing the event recording, each channel on the NVR is still set to the same 2-4MB buffer, the same as the individual cameras. So you would not get more pre/post recording capacity with 1x 8MP than you would with 8 x 8MP cameras on an NVR.)
I've had my Hikvision set up a few months now and I've noticed something has changed. I thought it was explained by what you said above but after some testing it isn't.

I started with 2 x 4 Mp cameras and Event recording only and I got the 5s pre-record period (or whatever I set it to) and never thought more about it.

I added 2 more 4 Mp cameras and moved to Continuous recording but noticed that when using the NVR playback in Event mode all the events started late or just a few seconds after the trigger point.

I read your post above and thought "aha, so that's why". It didn't bother me too much as iVMS worked and I had continuous recording so all the footage was there if I needed it. However, it was bugging me so I did some tests.

I took 2 cameras out of the system so that it was as it was when I first had the system.

When using the Event recording only I get the pre-record as I remember when I first had the system, but only in the Normal playback mode. In the Event playback mode all the events still start late even though the footage does exist and you can see it in Normal playback when only events are show on the timeline.

So I think there is a bug here that could make a user think it is the buffer issue (it seems to be strange that this should exist at all when there is whole HDD to record to - but it is what it is) but in fact it isn't in this case as the event playback is always late whether I record with 2 or 4 cameras, and with or without Continuous recording (which ensure the footage exists).

What seems to be wrong is event playback starts at the wrong time regardless. I don't recall this so I wonder if this is a recent firmware bug? Or maybe when I started out I never used playback in event mode as I only had events recorded anyway.
 

JB1970

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It's always been an issue. If you use continuous recording, switch the pre record to 0 secs in recording schedule advanced otherwise you may get skipping playback at the point the event is detected. It'll still play the 5 secs before the event when you playback even when set to 0.
 

Dav55

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Hi,


Thanks for this guide - very useful.

I am seeking to maximise the amount of recorded days on my available disk space so I have made the following settings (from the NVR) - The aim being to have the best quality recordings on Motion / Line Crossing and then lower quality for general – or in case an event isn’t triggered

Settings

Set the frame rate to 15 on Main Stream (Normal)
Set the frame rate to Full Frame Rate on Main Stream (Event)
Set to continuous record.

I have then set (in advance settings - as above) the pre and post record to 10 seconds.


Questions

  1. There isn’t a stream type for Event (in the advance settings) will this achieve what I want
  2. I got a bit lost on the information about buffering times – any further explanation would be good
  3. Is there a way when playing back to see the actual frame rate to test the output of these settings (I think I've seen that on ispy) is there any video players that can display frame rate?
 

JB1970

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Hi,


Thanks for this guide - very useful.

I am seeking to maximise the amount of recorded days on my available disk space so I have made the following settings (from the NVR) - The aim being to have the best quality recordings on Motion / Line Crossing and then lower quality for general – or in case an event isn’t triggered

Settings

Set the frame rate to 15 on Main Stream (Normal)
Set the frame rate to Full Frame Rate on Main Stream (Event)
Set to continuous record.

I have then set (in advance settings - as above) the pre and post record to 10 seconds.


Questions

  1. There isn’t a stream type for Event (in the advance settings) will this achieve what I want
  2. I got a bit lost on the information about buffering times – any further explanation would be good
  3. Is there a way when playing back to see the actual frame rate to test the output of these settings (I think I've seen that on ispy) is there any video players that can display frame rate?
I think, unfortunately, you’ll cause issues having the system set that way. Main Stream (continuous) and Main Stream (event) should have matching settings. Usually on newer firmware when you set the Main Stream (event) differently using the local menu, you’ll see a pop up warning telling you that.

If you need to maximise recording times you might be better using scheduling to switch between continuous recording and event only recording for day and night respectively.

My recommendation would always be to decide how much time you need to store the video for and fit the appropriate sized hard disc(s) to suit. For a domestic system I’d normally base this on the maximum length of time you’re ever likely to be away (holiday) plus a few days, so that if something occurs as soon as you go away, you’ll have a little time to retrieve footage on your return.
 

Dav55

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Thanks - completely agree with your recommendation for a domestic setup (which this is) about extending the HDD to cover holidays - wise words.

I am keen though to see if this set up works. It seems that Hik wanted it to be used like this - otherwise there wouldn't be a separate Frame Rate for Event ??

With that in mind, does anyone know if there is a way to see the actual frame rate recorded on a particular video file?

Thanks
 

JB1970

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1,236
Points
113
Thanks - completely agree with your recommendation for a domestic setup (which this is) about extending the HDD to cover holidays - wise words.

I am keen though to see if this set up works. It seems that Hik wanted it to be used like this - otherwise there wouldn't be a separate Frame Rate for Event ??

With that in mind, does anyone know if there is a way to see the actual frame rate recorded on a particular video file?

Thanks
Yes I don't know why it was this way originally but it obviously causes issues or they wouldn't now advise against it with a pop up message.

Not sure whether you can see that after recording, but it would be noticeable during playback and might be viewable if playing back using vs player. However, if you have a monitor connected to the NVR you can watch the frame rate during live view. First make sure you're watching the main stream, then just hover over the bottom of the image so that the toolbar pops up, then hover over the icon for information in the centre. That will give you the frame rate, bit rate, resolution, encoding and stream type. As you're viewing the same Main Stream that is being recorded, you will see the change as soon as an event occurs and see it restore when the event ends. I've just tried this in reverse, purposely setting Main Stream event down to 4 images per second and with a lower bit rate - the information updates in real time.

Edit: The pop up warning relates to the setting causing issues in exported AVI video specifically (though I still prefer to record the same high quality video at all times)
 
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Dav55

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Thanks, if anyone knows how to do this from a recorded file I'd be grateful.

I currently don't have a monitor connected to the NVR as its "securely out the way"

Using VLC player you can get some frame data, but not sure if this is for the current playback position or not.

I will keep trying, but look forward for any comments from any experts.

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