Live view - Camera time overlay - time out by 5 - 10 seconds

saltwater

saltwater

Getting comfortable
Oct 6, 2019
503
643
Melbourne, Australia
I only have two Dahua cameras connected (more on the way) and I've set things up where the camera embeds the date/time in the video feed. I have noticed that when viewing the live screen via Blue Iris that one video feed is 5 - 10 seconds behind the other. The time is correct but when watching one stream and then flicking to the next it's a matter of waiting a few seconds for the video to catch up. Is this normal and to be expected?

Here is a snap-shot of a live-screen view.

2020-11-30-BI-Time-Diff.PNG
 
Are you running a time server?
 
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sebastiantombs said:
Try this for a local time sync server -

Click to expand...
samplenhold said:
Cams will not hold their times. You need a time server like @sebastiantombs linked to.
Click to expand...

I've installed the time server, went back into the Dahua config tool, sycn'ed the time, and now in Blue Iris, in live view, both cameras are showing exact precise (now) time.

Is there anything else I should do? I noticed in the Dahua config tool a place to record a time-server but that I have unchecked.

Regarding the time-server, what would be the preferred settings? I set it to check every 3 hours and update if 2 seconds out, the default was check every 12 hours and 2 mins out.

ps. forgot to mention, thanks for the advice.
 
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saltwater said:
I've installed the time server, went back into the Dahua config tool, sycn'ed the time, and now in Blue Iris, in live view, both cameras are showing exact precise (now) time.

Is there anything else I should do? I noticed in the Dahua config tool a place to record a time-server but that I have unchecked.
Click to expand...

Yes, for each cam you'll enter the IP address of the computer where you installed the time server (for most, the IP of the BI server).

Regarding the time-server, what would be the preferred settings? I set it to check every 3 hours and update if 2 seconds out, the default was check every 12 hours and 2 mins out.
Click to expand...

Doesn't matter a lot for this purpose. 3 hours/2 seconds is fine.
 
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Why not use a BlueIris overlay instead of the one from the cam? Using it through BI you have the option to keep it or remove it when you export a clip. It also means all overlays will be synced up since they use BIs clock. So much more flexibility that way.
 
DarkHelmet said:
Why not use a BlueIris overlay instead of the one from the cam? Using it through BI you have the option to keep it or remove it when you export a clip. It also means all overlays will be synced up since they use BIs clock. So much more flexibility that way.
Click to expand...

Others might want to chime in with this one, but I was under the impression that it's less work for Blue Iris server. If that's not the case then, yes, I'll look at the Blue Iris overlay method.
 
I recommend using the ntp time server for the camera. For legal reasons the timestamp must be on the video. If it is done after the fact, you have modified the video. The video is now suspect as it has been modified.

Using time in bi uses more cpu.
 
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SouthernYankee said:
I recommend using the ntp time server for the camera. For legal reasons the timestamp must be on the video. If it is done after the fact, you have modified the video. The video is now suspect as it has been modified.

Using time in bi uses more cpu.
Click to expand...
I havent noticed any measurable increase with overlays since it's just saving text metadata to the BVR file. And for evidence, you'd have to export to an mp4 anyway. You wouldn't be giving anyone the BVR. When you export, you include the overlay.
 
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If you are actually supplying evidence, the BVR files must also be included, hence the camera time stamp since adding the time stamp to the video after it leaves the camera is altering the original video file. This may seem like spitting hairs but attorneys get rich on stuff like this, details matter in a court case.
 
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In another thread a user wrote that police don’t give a crap. Let me just say that when I was a LEO, if I received a clip from someone I wanted to make sure that the clip had not been modified so my case would stand up in court.

If the clip had been modified such as by Blue Iris overlaying time, I could see what happened and maybe who did it but couldn’t use the clip and would have to try another route to get a conviction.

Why use overlays if you think you might ever want to provide a clip to law enforcement?
 
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JNDATHP said:
In another thread a user wrote that police don’t give a crap. Let me just say that when I was a LEO, if I received a clip from someone I wanted to make sure that the clip had not been modified so my case would stand up in court.

If the clip had been modified such as by Blue Iris overlaying time, I could see what happened and maybe who did it but couldn’t use the clip and would have to try another route to get a conviction.

Why use overlays if you think you might ever want to provide a clip to law enforcement?
Click to expand...
So are you saying that it is better from a legal perspective, to have the camera itself stamp time on the video, and that way the native BI video clip would stand as not modified in any way?
 
I have received a clip from someone. I review it. If it is something I want to use in court, I ask the person if I can meet with them at the place that the camera recording device is (NVR or BI). I ask to see the original playback and if from BI, I would ask for the .bvr file and the exported clip be put on a USB stick that I provide. When the transfer of the two files is on the USB stick, I tag it and bag it.

In court I can testify that I watched the person transfer the files after I saw the original clip on their machine. I can testify that to the best of my knowledge, the clips have not been altered. If the defense attorney wants to object to the evidence, they can get an expert to testify that the files have been altered but have to prove it to the satisfaction of the judge and/or jury.
 
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