Dahua NVR -- where to set pre-recording seconds for IVS rule
- Thread starter JesseSR
- Start date
bigredfish
Known around here
Frankly I don’t see how it CAN work on an NVR.?
General and IVS recordings are completely separate recordings/clips.
If you’re not recording full time, the NVR doesn’t kick in to record until the IVS rule is tripped.
General and IVS recordings are completely separate recordings/clips.
If you’re not recording full time, the NVR doesn’t kick in to record until the IVS rule is tripped.
I'm not able to answer because I record full time. I'm such a BI non-expert that I don't even know if BI lets you not record full time. With the NVR I'm a bit mixed up. I thought if you're not recording full time, the pre-record buffer DOES work. Dahua made an early decision to use the Linux file system for indexing instead of doing their own indexing, and haven't yet seen the light and/or felt the pain to change it. I wonder if Hik does the same thing?
Yes you can set up to record in BI on triggers or confirmed alerts only.
You can set up a pre-time for it to record prior to the trigger.
But many, if not most here, record 24/7 as the substream doesn't take up that much storage.
Only if you tell it to with continuous recording. These are the various recording options:
When triggered. Video is only recorded when the camera is in a triggered state. The pre-trigger video buffer applies only to this type of video recording.
When alerted. Video is only recorded when the camera is in a triggered state and the alert has been confirmed by AI or otherwise.
Continuous. Record mainstream video 24/7.
Periodic. Record video in defined intervals for like a time-lapse.
Triggered + periodic. Combines when triggered with periodic.
Continuous sub + alerts. Records the sub-stream continuously, but the mainstream only recorded when the camera is in an alerted state.
Continuous sub + triggered. Similar to Continuous sub + alerts, but mainstream recording occurs upon trigger, not just alerts, ensuring that the main stream is recorded even for canceled alerts. This is the one most use.
bigredfish
Known around here
I've never understood the mindset of NOT recording full time AND IVS/Event triggers.
Having pulled video for various "activities" over the years, I would have been screwed in a high percentage not having full time recording to know what happened before and after an event.
Direction of travel before/after the event
Other co-criminals not seen in the event window
Other associated activity at neighbors or down the street
Missed a weapon or tool that wasn't present in the initial trigger event
Missed audio before/after the event
Possibly a vehicle of interest
--and on
I just don't think saving HD space is worth it
Having pulled video for various "activities" over the years, I would have been screwed in a high percentage not having full time recording to know what happened before and after an event.
Direction of travel before/after the event
Other co-criminals not seen in the event window
Other associated activity at neighbors or down the street
Missed a weapon or tool that wasn't present in the initial trigger event
Missed audio before/after the event
Possibly a vehicle of interest
--and on
I just don't think saving HD space is worth it
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Too many details I can't comprehend this early in the morning! From a strictly user standpoint:
With the NVR, when I click on an event, the playback starts at the event time.
With BI, the playback starts a few seconds before the event time, and it sure looks like it's the mainstream being played back.
Plus another big advantage with BI playback over viewing with smartPSS is that BI seamlessly retains the digital zoom and pan when crossing through triggers, while smartPSS cancels the zoom when a trigger is hit. This makes it really difficult to use when backing up a minute or so from a trigger to look at details, then when the trigger if hit, the digital zoom is suddenly gone.
With the NVR, when I click on an event, the playback starts at the event time.
With BI, the playback starts a few seconds before the event time, and it sure looks like it's the mainstream being played back.
Plus another big advantage with BI playback over viewing with smartPSS is that BI seamlessly retains the digital zoom and pan when crossing through triggers, while smartPSS cancels the zoom when a trigger is hit. This makes it really difficult to use when backing up a minute or so from a trigger to look at details, then when the trigger if hit, the digital zoom is suddenly gone.
bigredfish
Known around here
DMSS holds the zoom, I havent tried it on SmartPSS Lite.
But then I rarely digital zoom
But then I rarely digital zoom
BI playback is in mainstream before the event, but that setting is a different place than the prebuffer that works only for motion recording.
I'm thinking we're talking past each other a bit, so saying differently what I thought I tried to say
:First I'm talking only about IVS events, and I've set BI's record/pre-trigger-playback-time to 5 seconds. When I click the event in smartPSS, playback starts at the trigger time. When I click the event in BI, playback starts 5 seconds before the trigger time.
I'm thinking we're talking past each other a bit, so saying differently what I thought I tried to say
First I'm talking only about IVS events, and I've set BI's record/pre-trigger-playback-time to 5 seconds. When I click the event in smartPSS, playback starts at the trigger time. When I click the event in BI, playback starts 5 seconds before the trigger time.
LOL ok - I thought you were referencing this statement: "When triggered. Video is only recorded when the camera is in a triggered state. The pre-trigger video buffer applies only to this type of video recording." and you were indicating that you are running 24/7 and get this pre-trigger video, and my response was that BI giving you that playback 5 seconds before the trigger isn't this setting, but a different setting.
So yeah, BI will give you a playback of video prior to the event, but the type of recording dictates which setting is used to accomplish that.
bigredfish
Known around here
Just to add to the confusion...
All of my cameras, within the AI/IVS rule tab, have a "POST" record time. Mine is set to 10 seconds. I get that 10 seconds on ALL Devices
ON the NVR I have a Pre-record which is set to 5 seconds. I get that ONLY when using the AI search on the NVR
(I record everything full time + IVS)
View attachment Recording 2025-04-06 195633.mp4
All of my cameras, within the AI/IVS rule tab, have a "POST" record time. Mine is set to 10 seconds. I get that 10 seconds on ALL Devices
ON the NVR I have a Pre-record which is set to 5 seconds. I get that ONLY when using the AI search on the NVR
(I record everything full time + IVS)
View attachment Recording 2025-04-06 195633.mp4
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@tigerwillow1, can you confirm that DMSS also starts at the events? I just looked at my Ai camera in DMSS and found one that was able to start on its own seeing I have a complex setup that things kind of merge in to each other. however I found a clip of a human going by that triggered my IVS and started on that playback, I have my camera setup in storage to record 5 seconds and that pre record was to the second of when I could see them behind the tree to where the tripwire was and there was 5 seconds of playback before they crossed the tripwire. because of issues I don't use smart PSS because of time issues I get with using it. Does DMSS have same start at the tripwire? Is your camera under storage setup for the 5 seconds or longer if enabled seeing my camera only has 5 seconds of pre record.. well setup from 0-5sec..
bigredfish
Known around here
Yes I was also recording full time, However the playback in the DMSS was searched for IVS only and playback started 5 seconds before the event and has been that way before I started recording full time as well. As I said mine was little complex because of how things are setup but with IVS before event setup to record full time on main always played back with the 5 seconds of pre record that was setup in storage? Should it not do that if not recording full time?
Sorry I miss spoke, No I don't record full time in my Camera only on my NVR. So the search and playback was from camera and searched IVS.. So yeah little different as played back from Micro SD. Full time in NVR with IVS.. Again sorry I miss spoke..
So looking back in the NVR playback for that event even though it was setup and playback was marked as IVS the playback started much sooner in the DMSS on the NVR then it did on the Micro SD card of the camera. About 8 to 9 seconds before tripwire.
I can't because I'm not a DMSS user. If you have the camera SD card recording only events, I remember that it will start the playback before the trigger time. I've never tried 24x7 recording on the camera to know how that works.
EWW I just installed Smart PSS, Won't use it because yeah starting as the event is triggered WTH..