Hi Everyone,

I'm having an issue with some cameras lagging behind other ones. So if I'm watching the screen and someone walks past one camera, it can be a minute before they walk through the next one. It's quite confusing. Is there a way to sync the cams?

The system I'm running has 17 cams all doing H265 1440p25 @ 6Mbit (iframe 50) all on a gigabit backbone. The host server is a Dell R730 with 64GB RAM, 2 x E5-2695v4 and 8 x 10TB in RAID-10. CPU is 50%. The issue is not related to hardware performance.

Any help would be appreciated.

Thanks.

First thing to try is setting the iframe rate to match the frame rate.

The other thing is you don’t really need 25fps so maybe try dropping down to 20 or even 15fps. Although the cam specs may state that it will run at that rate the rate might well be the true upper limit of the cam hardware so pegging it back might help.

I'll try reducing the FPS and iFrame to 15 - but I doubt it is that. I use the same cams for my YouTube channel at 25 FPS with no issues.

https://www.youtube.com/watch?v=xeSL3xCPvnQ

I'm with Teaf (sorry - shortened that name). I think first step would be to make sure your iframes and fps match.... and it's worth lowering the fps a bit to experiment. It's easy enough to raise back up. I too have had hardware issues with fps too high (camera hardware, not the server) so it's something to test at no cost.

Before and/or after your changes it might be helpful to post your Blue Iris Status > Cameras tab. Sometimes there can be some info summarized in there that is easy to miss.

Thanks for the replies guys. I'm going to do that right now.

Here is the current cam status page.

All cams set to 15fps with an iframe of 15fps. Looks much better.

I wonder why in the original cam status that Blue Iris doesn't detect properly the actual FPS on the cam when they're set to 25? If I open the RTSP link with VLC it correctly states 25.

Anyway... will see how it goes. Thanks again for taking the time to reply, it's appreciated.

The second set does look much better, you're right.

I'm not a VLC expert to really refute but consider maybe instead that it could be the one that is wrong? I mean I'm not exactly confident in how either of them pull their figures but I'm definitely under the impression that BI is simply showing you what it's getting. It would appear that for one reason or another the cameras weren't keeping up. Anyway, hopefully your experience is as expected now.

If you added substeams I bet your system would be darn near idle!

VLC is correct. I also ran ffprobe to check the rtsp links, and they show the correct fps. So for some reason when the cameras are set to 25fps, BI isn't picking this up correctly, hence the fluctuating FPS in the first screenshot I sent.

Anyway, it has worked, so would like to say a big “Thank You”. I guess going forward, for future setups, I'll pin the FPS/iframe at 15.

In my experience, a lot of this is solved by enabling sub-streams. Without that, you're going to choke.