FPS and Bitrate

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Thixotropic
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FPS and Bitrate

Post by Thixotropic » Sun Jun 28, 2020 3:38 pm

This is a typical shot of the status screen for my BI system. What, if anything should be adjusted?
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cams-1.png
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I understand that the keyframe should be at or close to "1". Is that adjusted in each camera?

What am I looking for in terms of numbers? That is, what should they be?

Also, should I adjust things to drop the bitrate on some of these cams? Two cams are running at ~400Kb/sec, is that too high, or...?
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MikeBwca
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Re: FPS and Bitrate

Post by MikeBwca » Sun Jun 28, 2020 7:13 pm

The keyframe and fps is changed by loging into the cameras interface directly.

If you have a fps of 15, and a keyframe rate of 15, then the the 'fps/key' will show up in BI as '15.0/1.00'.

The numbers? 15 fps is adequate. But, if you want higher, and have plenty of cpu/gpu/memory/storage, the choice is yours.

I have all my cameras at 15 fps with a keyframe rate of 15. I have 7 1.3 mp cameras. Total is 208 MP/s.
HeneryH
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Re: FPS and Bitrate

Post by HeneryH » Sun Jun 28, 2020 11:44 pm

As a geek, can someone tell me the units for the keyframe number?

Seems like a pretty simple question.
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Thixotropic
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Re: FPS and Bitrate

Post by Thixotropic » Mon Jun 29, 2020 1:38 am

MikeBwca wrote:
Sun Jun 28, 2020 7:13 pm
The keyframe and fps is changed by loging into the cameras interface directly.
If you have a fps of 15, and a keyframe rate of 15, then the the 'fps/key' will show up in BI as '15.0/1.00'.
I'll have a go at this and maybe turn some of them down a bit so they end up at or near "1", which is what I understand is supposed to be optimal. (Is that correct?)


MikeBwca wrote:
Sun Jun 28, 2020 7:13 pm
The numbers? 15 fps is adequate. But, if you want higher, and have plenty of cpu/gpu/memory/storage, the choice is yours.
I have all my cameras at 15 fps with a keyframe rate of 15. I have 7 1.3 mp cameras. Total is 208 MP/s.
The pic shows the total BW at 423 MP/s. At this load the CPU usually runs between 20 and 25 percent usage so it sounds like I've got a little BW to spare.
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Matts1984
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Re: FPS and Bitrate

Post by Matts1984 » Mon Jun 29, 2020 12:29 pm

Thixotropic wrote:
Mon Jun 29, 2020 1:38 am
MikeBwca wrote:
Sun Jun 28, 2020 7:13 pm
The keyframe and fps is changed by loging into the cameras interface directly.
If you have a fps of 15, and a keyframe rate of 15, then the the 'fps/key' will show up in BI as '15.0/1.00'.
I'll have a go at this and maybe turn some of them down a bit so they end up at or near "1", which is what I understand is supposed to be optimal. (Is that correct?)


MikeBwca wrote:
Sun Jun 28, 2020 7:13 pm
The numbers? 15 fps is adequate. But, if you want higher, and have plenty of cpu/gpu/memory/storage, the choice is yours.
I have all my cameras at 15 fps with a keyframe rate of 15. I have 7 1.3 mp cameras. Total is 208 MP/s.
The pic shows the total BW at 423 MP/s. At this load the CPU usually runs between 20 and 25 percent usage so it sounds like I've got a little BW to spare.
I think you've already been replied to pretty well but I don't see anything wrong with your bitrates, especially assuming this is all traffic over your local LAN. Your cameras each probably have 100 MB interfaces and your server is likely 1 GB so you're not even stressing that aspect of it. The two at 400 kB is simply because those are higher pixel streams at 20FPS. It's quite interesting/impressive to try tweaking the settings on the camera interface and see how much it changes things in BI. For example, lowering "Front Yard - South" to 15 FPS would bring a significant reduction in Bitrate. Per the user guide and some reading on the other forum, yes a keyframe of "1" is ideal and as Mike also noted, I have mine set accordingly. In the camera interface you just need to set the key interval/frame interval (something like that depending on lingo) to the same rate as your FPS. This will help optimize alerting and who knows what else in Ken's masterpiece. Lastly, while not in your highlighted red box, you could try configuring the Sub streams on your cameras. I don't have anywhere near the same number of cameras but per my screenshot below, our total bitrates are similar however the MP/s my server needs to process are a very small fraction. The recordings are still just as good and in reality in the console, the VGA ".3MP" feeds aren't that bad! I've noticed no difference in alerts. Just food for thought.
Capture.JPG
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All that said, you've already said your system runs at about 20% CPU so you don't need the headroom. But if you're anything like me, if you can get the same results but run at 10% CPU..... then maybe :?: :?: With the substeams added, if your cameras support it you may be able to ramp UP the main streams. Again, your bitrates are nothing to worry about, it's the MP/s that affect the server.
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Thixotropic
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Re: FPS and Bitrate

Post by Thixotropic » Tue Jun 30, 2020 1:16 am

Hmmmm, not sure what to think.

I have two Reolink RL420s, and I dropped both of them (the Front-Yard cam and the Side-Yard cam) down to 15fps. In BI, I set the 'Max Rate' to 15fps (on the Video tab under 'Image Format'.

Looking in the Status screen below, I don't see any difference in the Key value- it's still at "0.5". Did I adjust the wrong setting?
status-at-15fps.png
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In the Reolink camera setup (below), this is about the only thing I can find that looks like it has anything to do with keyframe, except it's labeled 'Frame Rate'.
reolink-profile.png
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Matts1984
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Re: FPS and Bitrate

Post by Matts1984 » Tue Jun 30, 2020 12:23 pm

From my understanding, the "Max Frame Rate" in the BI settings is mostly useless. That said, I do always manually set it to match the camera.

On to the real topic... it doesn't look like the ReoLink has configuration options for the Key Frame from the screenshot. From a little googling, I found some reddit based info that seems to indicate some of their cams support it and others don't... and that it could be buried somewhere in "Advanced Settings". The "Frame Rate" is the regular FPS but there should (but maybe there isn't the option) be a separate option for Key Frame/I-Frame/something like that. Basically the "Key Frame" should be 1 per second and you generally have to set it to be once every XX frames which is why you set it to the same value.
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Thixotropic
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Re: FPS and Bitrate

Post by Thixotropic » Wed Jul 01, 2020 3:26 am

Here's the video setup page from a Microseven camera. If the "I-frame" interval is the keyframe (??), would I set that to '15' to match the 15fps setting configured in BI? Should the max frame rate in the camera also be set to '15'?
m7-profile-1.png
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Matts1984
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Re: FPS and Bitrate

Post by Matts1984 » Wed Jul 01, 2020 12:19 pm

So yes, at least per the BI manual... the "Maximum Frame Rate" and "I-frame" should be the same value. If you want that to be 15fps (I think that is likely perfectly fine), then yep! You should be able to almost instantly verify your settings on the BI Camera tab that we started this post with. Should be "15.00/1.00" (with minor fluctuations)

The rest of the settings on the Primary Stream look fine. Per your earlier screenshots, it doesn't look like you're using the Secondary Stream so those settings are irrelevant, as are tertiary.

FWIW, my understanding is that the actual fps of your stream will be solely dependent on the camera settings, not the "Max FPS" setting in BI. That value in the BI settings should auto-adjust as you tweak the camera to the highest value BI has seen recently. I don't think you can force a fps cap as the stream is what it is. I believe the field is mostly an informational tag more than a setting.
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Thixotropic
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Re: FPS and Bitrate

Post by Thixotropic » Wed Jul 01, 2020 11:13 pm

I set the max rate and the interval to 15 on both of the cameras and they now show 1.0 with minor fluctuations. Awesome, thank you.

I was able to tweak all the other cams except the front door and the 2 Reolink cams. It's a shame the Reolink cams don't offer this adjustment because the RL420 is a decent low-end camera (I think they're discontinued now).

The RCA front door camera only has the barest interface settings in the app; no video adjustments at all, zero, zip, nada. That's okay because the front door cam is going away before long- I'm switching to a wired cam with BI handling all the motion detection and alerting.
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