Bit Rate question

T

tward392

Pulling my weight
Sep 9, 2019
255
145
US
So, what Bit Rate do most people use? I'm trying to figure out why when I set my cameras up I customized it to 3072. Not sure if I read that somewhere but....

3072 Kb/S makes my .bvr files around 1.6 GB for a 1 hour clip.
8192 Kb/S makes my .bvr files around 3.9 GB for a 1 hour clip.

I just switched one camera to see the size difference for now.

Wondering if I did that for storage.... It's hell getting old and not remembering why you set something a certain way :D!

Here are the settings before the change....

1656680521311.png
 
Don't know why you did. Being an old guy too, don't remember why I do a lot that I do either. But, yeah, 3072 is low for a 4MP cam. 8192 will give better image quality. I tend to prioritize the latter for my purposes and not worry much about the storage effects. Storage is relatively cheap. As long as I have a couple of weeks for my cams in the aggregate, then I'm good. YMMV depending on requirements.

Uncheck that watermark box too. Don't need that.
 
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Same here. I crank it up. Hardware is cheap so it is my last concern. A good pic is my only concern. So for me, no debate on keeping these numbers really high.

My question becomes: when is a high number absurdly high. Is there a stupidly high number? If I run them all at 20480 (or whatever the max is for the camera in question) is that a super complete waste? Is there a formula that can tell me what is the highest number I need that at the same time not exceeding the max requirements the camera would ever need? Maybe the answer is that number does not exist, just place on max and let‘r rip?
 
I'm sure there is a "point of diminishing returns" when it comes to bitrate and absurdly high numbers. I tend to run my 4mp cameras at 8192 as I find it a good balance between decent picture quality and file size. But everyone is different. Certainly you can try higher bitrates and see if you can tell a difference from something like 8192 and if you feel the difference is worth the extra storage size.
 
Yeah, I get that. But if I remove storage from the equation, then there is no experimentation needed. And in my case anyway, I have zero concerns for hardware.
So I guess the answer for someone like me is again, let’r rip!

I just figured there was a known formula (something X something for max resolution/clarity for example) that would tell me that a 8MP camera would never use more than X bit rate.
 
As others said it is generally:

2MP = 4096 bitrate at 15FPS
4MP = 8192 bitrate at 15FPS
8MP = 16,384 bitrate at 15FPS

But it comes down to your eyeballs, field of view, and monitor you are looking at.

I start with these numbers and then go up and down and test it until my eyes say there isn't a difference. Obviously the lower you run, the more storage you save and vice versa. My 8MP seems to be around 12,288 before I do not notice an improvement going up.

Keep in mind OP since you are using BI, you really should be using the substream option and that will get you a lot more storage for the same GB. Prior to substreams, my 4GB camera was running about your rate of storage and now I am getting over 8 hours for the same GB. Obviously number of triggers come into play, but use the substreams!
 
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wittaj said:
As others said it is generally:

2MP = 4096 bitrate at 15FPS
4MP = 8192 bitrate at 15FPS
8MP = 16,384 bitrate at 15FPS

But it comes down to your eyeballs, field of view, and monitor you are looking at.

I start with these numbers and then go up and down and test it until my eyes say there isn't a difference. Obviously the lower you run, the more storage you save and vice versa. My 8MP seems to be around 12,288 before I do not notice an improvement going up.

Keep in mind OP since you are using BI, you really should be using the substream option and that will get you a lot more storage for the same GB. Prior to substreams, my 4GB camera was running about your rate of storage and now I am getting over 8 hours for the same GB. Obviously number of triggers come into play, but use the substreams!
Click to expand...

I do use substreams but I continuous record both streams.
 
My defaults are 10240 for 4MP cameras and 5120 for 2MP cameras because they look better on both my BI console monitor and in UI3, when I have my glasses on anyway. Recoding is continuous plus triggered to save some disk space. Storage is about 21-30 days, depending on how many triggers happen (windy days/moving shadows) on 11GB of total disk space.
 
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wittaj said:
Why not do continuous + triggers so that it records substreams until there is motion and then switches to mainstream resolution during the motion trigger? You will save a ton of storage that way.
Click to expand...
Yeah, as much as I don’t care about using up disk space, I agree with Wittaj, without reasonable justification, using resources with no valid argument is outside the scope of my interests.
 
Man you guys run high bitrates. Are you only using CBR with h264? I run my 4MP cameras around 4-5000 and the 8mp around 8-9000 for 15 fps.

I do vbr with h265. But they're residential and unless it's windy, they don't see enough movement to need the higher bitrate.
 
xxHi-Fixx said:
Man you guys run high bitrates. Are you only using CBR with h264? I run my 4MP cameras around 4-5000 and the 8mp around 8-9000 for 15 fps.

I do vbr with h265. But they're residential and unless it's windy, they don't see enough movement to need the higher bitrate.
Click to expand...
If you are using BI, then yes, using CBR and pure h264 will result in better results.
I can see a significant difference on my 4mp cams between 4096 and 8192 bit rates, no contest.
Here's the thing, it will fail you when you need it most. A moving perp could most likely end up being a blurry mess using your current settings.
Because the VBR can't always ramp up fast enough with movement to prevent it. And H265 is bad at macro blocking non moving objects and then can't correct its self fast enough to prevent a blurry mess of movement.

The main goal of surveillance is to know who did it, not just what happened.
 
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wittaj said:
Why not do continuous + triggers so that it records substreams until there is motion and then switches to mainstream resolution during the motion trigger? You will save a ton of storage that way.
Click to expand...

Didn't really think of that, continuous is what I was doing before substreams came along, I put substreams in to know down the CPU usage, but didn't consider space saving.

Not sure if I want to go that route yet as I like to look back over things that weren't caught by a trigger and would like to be able to see it better than a substream would provide. Guess I have to weigh how often this happens compared to how much space is saved.

I do like the better clarity of going from 3072 to 8192, so I might have to change the other cameras to do the same thing. Will just have to get more space if needed!
 
You would be surprised how well a D1 sub at 1024 bit rate is and still low CPU

How much resolution is really needed for LPR

We have folks come here all the time thinking that more MP is better, whether it be for general purposes or for LPR. Those of us that have been around long enough know that sensor size is more important than MP. Those that have been here awhile know that I share a representative sample of...
ipcamtalk.com ipcamtalk.com
 
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looney2ns said:
If you are using BI, then yes, using CBR and pure h264 will result in better results.
I can see a significant difference on my 4mp cams between 4096 and 8192 bit rates, no contest.
Here's the thing, it will fail you when you need it most. A moving perp could most likely end up being a blurry mess using your current settings.
Because the VBR can't always ramp up fast enough with movement to prevent it. And H265 is bad at macro blocking non moving objects and then can't correct its self fast enough to prevent a blurry mess of movement.

The main goal of surveillance is to know who did it, not just what happened.
Click to expand...


Those issues are unfortunate and I uncertainly don't have them but I don't use Blue Iris.
 
wittaj said:
The advice given is sound advice regardless of VMS platform. CBR and a higher bitrate is better.
Click to expand...
Sure. Wasteful and ineffecient but it is more fool proof to just recording at max settings with little to no compression.

Guess it depends on what you're trying to do, priorities and being realistic with capabilities and understanding capabilities.
 
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None of us said to run at max settings with no compression (not even possible).

We have given advice developed by many long time members here that play with these cameras and figure out the optimal sweet spot for performance.

It is up to you to decide what works best for you and what advice to listen to. But if you run too low bitrate, vbr, and h265 you will certainly have an event happen that your camera misses and then you will be posting to this forum asking how to improve the image....it has happened to many people...

Try it yourself and realize like most of us that the savings running h265 and vbr is no where near theoretical numbers. Mine was literally minutes difference so I go for the higher quality....
 
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wittaj said:
None of us said to run at max settings with no compression (not even possible).

We have given advice developed by many long time members here that play with these cameras and figure out the optimal sweet spot for performance.

It is up to you to decide what works best for you and what advice to listen to. But if you run too low bitrate, vbr, and h265 you will certainly have an event happen that your camera misses and then you will be posting to this forum asking how to improve the image....it has happened to many people...

Try it yourself and realize like most of us that the savings running h265 and vbr is no where near theoretical numbers. Mine was literally minutes difference so I go for the higher quality....
Click to expand...

That has not been my experience. Typically when I do an audit or a customer says we were told we would get 45 days and we are not it's because cameras were left at h264. I remotely connect and change every camera to h265 and that alone drops the average bitrate by 20-30% overall. When I connect later that day the storage forecast reaches out that much further.

I'm not sure of what capabilities Blue Iris has. Never used it, I only assume it's comparable. I know it is very DIY and it's not as well expensive but we use DW Spectrum and there are a lot of storage tools that show you where your storage space is going and which cameras are using up all the disk space. It will forcast storage timeline based on bitrate usage over different amounts of time. Blue Iris could also do this? Not sure but probably. There is a very real difference between h264 and h265 though. I can say h265 didn't work that well with older software versions and it's greatly improved in the last 2 or so years.

As far as bitrate, it depends on what you're seeing. Indoor cameras don't need the bitrate max like an outdoor. Outdoor cameras don't need the bitrate if they're viewing a loading dock or employee entry. We rarely do residential but the cameras at my home need a little more because on a windy day all of the trees and hostas are blowing all over the place. It comes down to adjusting for the environment.

I also don't worry about VBR ramp up because the second it takes for that isn't going to make a difference.

LPR cameras are of course different. I run the 8192 on my 4mp LPR that only does h264 and it's CBR. But I do motion activated hi res recording with a 10 second pre/post buffer to help
 
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