What Bitrate to Use

[czrabode]

Hi. I just wanted to ask what bitrate you guys use. I don't want to set it too low so that my image will be unusable to "catch the bad guys".

I have 9 Dahua Starlight Cameras attached to a Dell OptiPlex i7 6700 with 16 gigs of RAM, a 250 GB SSD and an 8TB Purple Drive.

I have disabled Windows Defender. I have also disabled motion detection for cameras that don't need it. The cameras are set to write to disk directly. I have turned off overlays from Blue Iris.

The frame rate is set for 25 fps. Is this too much or just right?

I have initially set the bitrate to 4096 Kb/S and was getting around 60% CPU utilization. When I set the bitrate up to 6144, the utilization came up to 85%.

I would like to set the bitrate even higher. Storage is not an issue. I can get another 8TB hard drive. But I don't think my CPU can take it.

I am afraid I might have to swap up my CPU if I pick a higher bitrate. =(

Any insights from experienced users will be appreciated.

 

[SouthernYankee]

Set the frame rate to 15
set the Iframe to 15
set the bite rate type to VBR
set quality to 5
set smart codec to off

what is the encode mode set it to H.264H

Are you using BI as a service ?
Is BI on a standalone machine , no other applications running ?
IS BI set to use Intel hardware acceleration, Make sure you have the correct driver, (see other posts)

Your CPU with out the display up should be less than 40%

How is the network configured ? is the BI PC able to access the cameras without going through the router ?

 

[looney2ns]

Read the Wiki about optimizing BI.

 

[czrabode]

@SouthernYankee I followed your settings and the CPU utilization dropped to around 35. Can you explain what the difference is between VBR to the other setting? Also, in BI, under the Video Tab, which option should I select as far as "H.264/5 HW Decoding"? Should I check "Also BVR"? Should I check "Limit decoding unless required"?

To answer your other questions about my current settings:

• Encode mode: H.264
• BI as service: No
• Is BI standalone machine: Yes (the only other application running is Google Chrome Remote Desktop)
• BI set to use hardware acceleration: Yes
• Network configuration: Dual LAN as described in cliff notes. 9 cameras are spread out between 2 POE switches and the switches merge into one unmanaged switch and then this goes into the second NIC. The first NIC is for internet.

 

[czrabode]

Oops. I somehow missed that part.

 

[SouthernYankee]

VBR variable bit rate
CBR constant bit rate.

Search Google for VBR CBR.

VBR keeps quality the same, it uses less band width for static images.

Read the info in the WIKI

 

[bp2008]

I don't actually recommend setting the iframe interval equal to the frame rate unless you have a good reason to do it.

The benefits of a low iframe interval are:
1) In rare cases a shorter iframe interval can fix stream stability problems.
2) Better performance when seeking in a recording.
3) "Direct to disk" recordings must start at an iframe, so if you record on motion detection, the start of the recording can be delayed up to one full iframe interval. You can fully make up for this by using a longer pre-trigger video buffer.
4) When using the "Limit decoding" feature, a shorter iframe interval gives you more frames for live viewing and motion detection.

However those benefits also come with a cost, and that is higher bit rate and/or lower quality because iframes eat up far more of the total bit rate than other frame types. Poorly tuned encoders also have a visual pulsing effect whenever an iframe appears in the stream. (really, I shouldn't say "poorly tuned", because the pulsing effect comes from tuning for low latency at the cost of image quality)

 

[john-ipvm]

Set the frame rate to 15
set smart codec to off

I am curious to the recommendation of setting smart codec to off. Have you noticed specific quality or imaging problems with Dahua cameras with smart codec on or?

 

[bp2008]

We've seen problems in the past running Blue Iris along with some cameras' encoding tricks like "smart codec". It is an ever-changing landscape though, between firmware updates and BI updates. In some situations I'm sure smart codec will work just fine with Blue Iris, but in others it could result in video corruption or worse.

I'd say it is good advice to give to someone who is looking to perform the least amount of troubleshooting.

 

[czrabode]

I don't actually recommend setting the iframe interval equal to the frame rate unless you have a good reason to do it.

The benefits of a low iframe interval are:
1) In rare cases a shorter iframe interval can fix stream stability problems.
2) Better performance when seeking in a recording.
3) "Direct to disk" recordings must start at an iframe, so if you record on motion detection, the start of the recording can be delayed up to one full iframe interval. You can fully make up for this by using a longer pre-trigger video buffer.
4) When using the "Limit decoding" feature, a shorter iframe interval gives you more frames for live viewing and motion detection.

However those benefits also come with a cost, and that is higher bit rate and/or lower quality because iframes eat up far more of the total bit rate than other frame types. Poorly tuned encoders also have a visual pulsing effect whenever an iframe appears in the stream. (really, I shouldn't say "poorly tuned", because the pulsing effect comes from tuning for low latency at the cost of image quality)

So what frame rate and I frame rate do you use?


Sent from my iPhone using Tapatalk

 

[SouthernYankee]

Following other recomerecommend. Use frame rate of 15 or lower. Use an I frame of 15 or higher. I have used frame of 15 and iframe of 30, but missed some activities in an alert. But was recoverable as It is continouscon recorded.

With frame of 15, iframe of 30 you can loose the first 2 seconds.

Czrabode with the changes what is the reported frame rates in BI now ?

 

[czrabode]

@SouthernYankee, with the changes, the CPU utilization dropped to 25%.

When I activated run as service, it dropped down to 7%! Amazing!


Sent from my iPhone using Tapatalk

 

[fenderman]

@SouthernYankee, with the changes, the CPU utilization dropped to 25%.

When I activated run as service, it dropped down to 7%! Amazing!


Sent from my iPhone using Tapatalk

running as a service will not drop the cpu usage like the...its likely that you are not displaying the console while running as a service and that is giving you the reduction.

 

[jrf]

Set the frame rate to 15
set the Iframe to 15
set the bite rate type to VBR
set quality to 5
set smart codec to off

what is the encode mode set it to H.264H

@SouthernYankee What do you set your "Max Bitrate" to with the above settings?

 

[SouthernYankee]

I use 4096, because I like a good quality. But you can use 2048.

 

[looney2ns]

For best results, in the camera set the Iframe to the same as your framerate.

 

[Oceanslider]

I don't actually recommend setting the iframe interval equal to the frame rate unless you have a good reason to do it.

The benefits of a low iframe interval are:
1) In rare cases a shorter iframe interval can fix stream stability problems.
2) Better performance when seeking in a recording.
3) "Direct to disk" recordings must start at an iframe, so if you record on motion detection, the start of the recording can be delayed up to one full iframe interval. You can fully make up for this by using a longer pre-trigger video buffer.
4) When using the "Limit decoding" feature, a shorter iframe interval gives you more frames for live viewing and motion detection.

However those benefits also come with a cost, and that is higher bit rate and/or lower quality because iframes eat up far more of the total bit rate than other frame types. Poorly tuned encoders also have a visual pulsing effect whenever an iframe appears in the stream. (really, I shouldn't say "poorly tuned", because the pulsing effect comes from tuning for low latency at the cost of image quality)

So what frame rate and I frame rate do you use?


Sent from my iPhone using Tapatalk

bp2008
been searching this subject and you are pretty much the only one I have seen say not to set the Bit Rate and iFrame rate same. How much lower do you typically set the iFrame rate, let say, if you have the Bit Rate set at what seems to be the very common 15 Bit Rate?

 

[SouthernYankee]

Ocean
That is not bit rate, that is Iframe rate. The standard recommendation is frame rate equal to the Iframe value, So there is one complete full frame every second.
Bit rate type I recommend VBR. Bit rate depends on frame rate, the size of the frame, the quality of the video, the complexity of the frame, the amount of motion... pick a number 8192, move up or down based on what you see for video quality.

 

[bp2008]

I set my iframe intervals usually to 2 or 3 times the frame rate, because a longer interval improves the compression ratio. But I am very much aware of the side-effects of doing this.

Setting it equal to the frame rate can be advisable for newbies however because it can solve some rare video corruption problems, makes the start time of motion-activated direct-to-disc recordings more predictable, and makes BI's "limit decoding" feature decode more frames. All at the cost of somewhat less efficient compression, which is not a big problem for most systems.

 

[MikeyTech8]

I don't actually recommend setting the iframe interval equal to the frame rate unless you have a good reason to do it.

The benefits of a low iframe interval are:
1) In rare cases a shorter iframe interval can fix stream stability problems.
2) Better performance when seeking in a recording.
3) "Direct to disk" recordings must start at an iframe, so if you record on motion detection, the start of the recording can be delayed up to one full iframe interval. You can fully make up for this by using a longer pre-trigger video buffer.
4) When using the "Limit decoding" feature, a shorter iframe interval gives you more frames for live viewing and motion detection.

However those benefits also come with a cost, and that is higher bit rate and/or lower quality because iframes eat up far more of the total bit rate than other frame types. Poorly tuned encoders also have a visual pulsing effect whenever an iframe appears in the stream. (really, I shouldn't say "poorly tuned", because the pulsing effect comes from tuning for low latency at the cost of image quality)

I have my Fps set to 25 for reasons. For this 25fps, may I ask what iFrame interval to set it to? I too have notice my motion detection not accurate/missing/late a few seconds .