Hikvision DS-7604NI-K1 / 4P NVR Recording Problem

[needforsuv]

I recently had a Hikvision DS-7604NI-K1 / 4P installed with 4 DS-2CD2155FWD-IS Cameras (Australia) using PoE.

I've noticed that the NVR has a tendency to drop frames in the Main Stream during recording (I use H265 on all of them) but the substream is almost always fine. I am nowhere near the maximum input bitrate. (30 of 40 MBPS) which has >25% margin so it should be plenty.

Today I managed to record ALL 4 Cameras successfully via the NVR's Live View which turned out smooth and fine.

However, on the NVR's internal recording on the same section where it recorded motion on one of the cameras, there were some dropped frames at the start of the video.

If I turn the bitrate up, both the Live View and NVR recording suffers from frame drop issues; however, if I can see live view and record it smoothly (current settings), I don't see why the NVR recording on the HDD will have issues as it all goes through the same input.

I've linked the my google drive folder containing the original files, I would love to know what could be causing this.

Live View and NVR HDD 7 June 2019 - Google Drive

Details:
NVR Firmware Version V3.4.93 build 171118
NVR Encoding Version V5.0 build 170703
NVR Web Version V4.0.51 build 171117
NVR Plugin Version V3.0.6.13

IPC Firmware Version V5.5.51 build 180408
IPC Encoding Version V7.3 build 180205
IPC Web Version V4.0.1 build 170711
IPC Plugin Version V3.0.6.26

Region: Australia, PAL 50Hz
Recording at 2560x1440@25p for the main Stream (various bitrates), Sub-stream is 640x360@25p.
The reason the sub stream is set at 25 is because the main stream doesn't have any pre record and temporal information is more useful to me.

 

[alastairstevenson]

The reason the sub stream is set at 25 is because the main stream doesn't have any pre record

Do you mean that you have configured it that way? Not something I've tried, I can't think of a reason to do that.
I'm wondering if that could have a bearing on dropped frames at the start of motion.

 

[needforsuv]

Yeah, I've configured it to 25. But as installed it was at 6MP (Full frame 15 fps) and it was dropping frames throughout videos (all at 8Mbps). I've since tweaked it so it does it less, but I've also opened up the WDR a bit so it has more visual information (not that it matters, since it happens at high bitrates even at lower frame rates).

I mainly use it to monitor for animals, people, parcel deliveries and such (Some of my parcels end up in front of my door but my gate is locked and closed, so there's some probably some tossing or fence climbing involved). Anyway, I have an i7 but 4 Full Frame 6MP's just won't load up on live view quickly so I turned down the resolution and upped the frame rate to compensate (I could use the substream, but I wouldn't see any details when I zoom in). In other words, I prefer motion clarity as that's the most prominent information when something is recorded in my use case.

Thing is, I recorded off live view just fine but the NVR didn't record it correctly and it works fine the rest of the video.

At first I was thinking it was the current bitrate boosting higher than the NVR can handle, but the recorded live view taken from the same input not having issues disproves it - if the frames are being dropped from camera to NVR (due to limited input B/W), it'll show on the live view as well. It's the NVR dropping the frames, but somehow it outputs the video just fine.

Currently, if I set the bitrate higher (where it possibly exceeds the incoming bandwidth of the NVR), it will drop frames in live view and in recordings (expected behaviour since you need more NVR bandwidth for that not to happen). However, the problem is in this area where I can live view mostly fine (4 streams almost maxes out my CPU and some streams might not decode in exactly real time so they just sync back up once every 10 seconds or so), but the NVR doesn't save it to the HDD correctly.

Could it be that the NVR somehow isn't writing it to the HDD correctly? It seems odd considering there are NVR's with a lot more bandwidth which still use a single drive. 30 seconds of pre-record is about 1 second of the main stream in terms of storage, so it doesn't have a problem putting that 30 second from the 'buffer' into the drive and then continue recording the sub stream.

I have a hunch it might stop it if I remove a stream or lower a bitrate massively, but that kind of defeats the point.

As my understanding of Hard drives goes, they have much better sequential performance; but within 2 seconds, all of the burst should be over and into sequential writes. Thing is, at 40Mbps max input (5 MegaBytes /sec), you have at least 20x to go before sequential performance is a problem. I don't know how the NVR deals with pre-record or motion detection, but the internal buffer would probably be faster than the maximum input speed like most things (Cache, RAM, PCI-E, etc.).

It's not a problem if the sub stream is usable for the missing motion, but it's just a little annoying.

EDIT:
I might not have understood your response; if you thought my main stream is SET to no PRE-RECORD but the sub stream is, that ISN'T true. I've set it to deal stream with PRE and POST record, however, only the substream ends up with pre-record when viewing back later (both get post record, obviously).

And that is why I set the substream to the same framerate as the main stream, it just catches anything before the motion was detected and helps identify things like what caused the motion detection or what happened, etc.

According to my calculations, 30 seconds of main stream will indeed be on the order of several dozen MegaBytes, so that probably doesn't have a buffer or not enough of one. (The NVR would probably have problems if it 'buffered' the main stream with pre record and is limited to the same Bandwidth of 40MBPS as per the input.)

(My computer is about 2-3 dozen meters - 50-100ft - of ethanet cable away from the NVR and my HDD isn't exactly the best (7 years old, ~1/3 full, a few corrected errors, and non-zero standing error rates - still ok on smart though), but it records 4 streams fine everytime (provided the sync is right) and on this occasion, managed to record where the NVR failed.)

 

[alastairstevenson]

I might not have understood your response; if you thought my main stream is SET to no PRE-RECORD but the sub stream is, that ISN'T true.

Yes, that's what I thought.
But with the problems being during normal recording as well, it won't be due to that.

(7 years old, ~1/3 full, a few corrected errors, and non-zero standing error rates - still ok on smart though

That might be a factor then - if the HDD is doing some re-trying and causing a long enough delay to drop part of a buffer.
The SMART summary only goes bad when the HDD is really bad - presumably the errors you've mentioned are from the SMART detail.
I'd treat errors like that as indications of a faulty disc.

 

[needforsuv]

Yes, that's what I thought.
But with the problems being during normal recording as well, it won't be due to that.


That might be a factor then - if the HDD is doing some re-trying and causing a long enough delay to drop part of a buffer.
The SMART summary only goes bad when the HDD is really bad - presumably the errors you've mentioned are from the SMART detail.
I'd treat errors like that as indications of a faulty disc.

It's my PC with the old HDD that's recording fine. The NVR has a BRAND new HDD but it can't record the frames my PC can...

I can't imagine how an ethanet switch and 50-100 ft of cable later, how my pc recorded the live view fine but this instance the NVR didn't record the motion fine if it passed them through fine.

Obviously this happens when I don't record the live view either, I just so happened to have recorded and watched it live view fine when it detected the motion and recorded.

It doesn't do it every time, but when it does it it's a slight annoyance.

Obviously, the NVR should prioritise recording over live view right? But in this instance, I managed to get a better picture from the recorded live view.

 

[alastairstevenson]

It's my PC with the old HDD that's recording fine.

OK, it seems I didn't properly read what you'd said, and misunderstood.

I can't imagine how an ethanet switch and 50-100 ft of cable later, how my pc recorded the live view fine but this instance the NVR didn't record the motion fine if it passed them through fine.

Yes, that does not seem logical.

 

[needforsuv]

I get that if the incoming bitrate is boosting over the NVR's limit, both the live view and recorded video will have issues, but live view is consistently smooth for me at the current settings but somehow it manages to not record the frames that I got from live view in this instance.

There is just no way adding the sub stream to the recording will make the difference when it only accounts for seconds of the main stream.

If anyone has any idea what could be causing this, I would love to know.

I know surveillance HDD's are optimised for continuous recording, but this is ridiculous, only 4 streams causing issues when they support a lot more?