Thursday, September 17, 2020

Syncing time

The issue

One of the things suggested to save CPU on Blue Iris is to turn on the in camera overlay instead of having Blue Iris add it while viewing. Note this works most of the time but some instances in camera overlays mess with tools like LPR. But many of the clocks seemed to refuse to keep time. At first I thought it was the local ntp servers having problems and wrote a quick tool to test all my ntp server options. The real issue is I'm finding different models of cameras work with only some ntp servers. In a perfect world this would not be an issue but in the real world they are often off a bit from each other and for syncing of video you want them a close as possible. And it also means you need to know which cam works with which and set them to ones as close in time as possible. Plus I want to avoid uploading packets where possible given my network connection is 900 down with only 40 up and I'm backing up to the cloud contentiously. 

Main options I have to work with are:

  • internet time servers ( for instance)
  • ntpd on OPNsense router box using as source
  • Windows time server on a Blue Iris server using as source
  • NetTime on a Blue Iris server using as source
  • ntp service running on IoT Unifi network gateway using as source

Note just setting the time server you want to use on a Windows 10 PC gets complicated. Microsoft really wants you to use Detailed instructions to change the server can be found here.

What worked with what


System->System Settings->Time Settings (ColorVu)

Basic Configuration->System->Time Settings (older cams)

Would not even ping most of these. In the end the only one it would connect to was the Windows time server

ColorVu screen shot



Only seems to like the OPNsense box. Takes 3 screens to set all the time options.


System->General->Date & Time

Hard to say since there is no test button. You just set it and hope. I'll set them to diff servers and see what keeps time. Though it looks like it might do a sync on save so you can see if something works if the time was off. After a day it appears OPNsense did not seem to work as the time was WAY off.

Used Windows time server 


System->General->Date & Time

Like Amcrest (some claim the Dahua makes many of Amcrest cams and the software is very similar) it is hard to say since there is no test button. You just set it and hope. I'll set them to diff servers and see what keeps time. Though it looks like it might do a sync on save so you can see if something works if the time was off. After a day it appears OPNsense did not seem to work as the time was WAY off.

Used Windows time server 



Not sure if this is working or not. Comes set to which seemed to be working. When I set it to a local one it changed the date to 2036 and stayed there till I "Synced with PC time". Then tried to dup and could not. Set to OPNsense box. After a few days the time seems to be hold so think is OK. Note there is no option to set DST start and stop.  


Basic Settings->Camera Time
OPNsense seems to work OK. Note this old enough there is no option to set DST start and stop.


Again OPNsense seems to work OK. 

Tuesday, September 15, 2020

Quick outdoor audio compare


Been seeing posts wanting cams with audio lately. My Ring compares playlist has some examples of the diff between a ColorVu and a Ring doorbell that contain audio but when outside doing a bit of weeding around the bird feeder and hearing coyotes playing near by I thought I'd grab the footage form 3 near by cameras to show the diff between them.

The 3 cameras are:

Dahua IPC-HDW4631C-A mounted under the window AC unit

Reolink RLC-511-5MP mounted on side window frame

Hikvision (ColorVu) DS-2CD2347G1-LU (far one) mounted on the soffit at the corner of the roof

Placement of cameras

The links to the videos are:

  • The Dahua video
  • The Reolink video
  • The Hikvision/ColorVu video

If you watch the lower timestamp you should hear:

  • Various bird calls and till 11:28:40
  • @11:28:40 you should hear my footsteps and the hedge trimmer starting up.
  • @11:29:37 you should hear me walking through the dried "weeds" crunching them and a jet passing overhead. Then me tossing the branches into a pile off screen.
  • @11:29:58 I start using the hedge trimmer again.
  • @11:30:07 I stop and you can hear what sounds like coyotes yapping a few hundred yards away.
  •  @11:30:23 you should hear me say "listen to that" (meaning the coyotes) in a normal speaking voice.

It is totally calm so there is no wind noise to deal with. I should probably do another sample with speaking when there is wind and when the house main AC unit (around the far side of the house) is running. I'm amazed how loud that AC unit sounds on footage compared to when I'm in the yard.

Saturday, September 12, 2020

Fact check: Amcrest cameras are Dahua rebrands.

 I hear people say this a lot but when you try and ping them down they never seem to be able to tell you which model is which. There are post like this one where people claim they have up Dahua firmware on some models of Amcrest cameras which they think implies Dahua made them but they do not know which model. Usually I just don't have the time to look into it with so little to go in. This one claims to have upgraded an Amcrest model I have, the Amcrest IP8M-2496EB, so I thought I'd take a it to see if I could actually find a Dahua model of that cam and if the Amcrest was any cheap or if there was any other reason to buy the Amcrest of just getting the Dahua (if there was on). The firmware mentioned,, is used by a few models.

The Dahua wiki shows 3 8MP bullet models including the IPC-HFW2831T which is one of my current favs. Nothing that looks close to the Amcrest. But I'm not finding my Dahua 6MP model there either so not definitive.

A look at the Dahua product selector seems a bit more promising as it has my 4631 listed but still nothing that looks like the Amcrest. However the IPC-HFW4831E-SE is close and the specs match. The actual case is just a bit different.

A quick google search shows the IPC-HFW4831E-SE can be had for as little as $150 The Amcrest IP8M-2496EB can be had for as little $95. So I guess the main factor is price. But as my tests have shown you are generally better off with the 6MP Dahua IPC-HFW4631H-ZSA for as little as $110 and get a serious zoom and audio too for that extra $15. There does not appear to be an Amcrest equiv of the 6MP Dahua IPC-HFW4631H-ZSA.

If you want to compare the camera software features between the 2 8MP cameras you can get the Dahua manual here and the Amcrest IP8M-2496EB manual here.

So lets try another. The Amcrest IP4M-1026  which has similar low light performance to the Dahua 6MP IPC-HDW4631C-A Note you get 20% more rez plus audio for just $10 more than the Amcrest. The Amcrest it pretty distinctive with its angled shade and case. None of the Dahuas look anything like it. Same goes for the "eyeball" version IP4M-1055E. The closest Dahua match appears to be the IPC-HDW2439T-AS-LED-S2 which appears to be cheaper than the Amcrest.

So we are 1 for 3 which means some of them my indeed be made by the same people that make some of the Dahua cams. If Dahua makes all of its models is still a bit unclear. The Chinese supply chain seems to cross a lot.  But I don't think it matters all that much. Once you sort the specs you want for a cam you can see what models of what brands match up and then see if any one has loaded a more feature rich firmware on it or even give it a try yourself. It seems that in many cases the loader with not load something that will brick the cam though in some cases you might lose a feature you liked and not be able to go back.

You might also want to look at this Wikipedia entry which outlines known Dahua security issues.