Hi, trying to adjust the PTZ5A4M-25X bit rate

[quantum999]

Hi, I have been slowly building my system over the last few months and my last camera is the PTZ5A4M-25X. I like to continuously record my other cameras at maximum bit rate but I am struggling with that one.

The web interface maximum bit rate is 9728 Kb/s which I thought was a bit low. Enabling to ROI over the whole picture results in wildly varying bit rate. Set at quality "6" I get a stable 53Mbps in complicated images (shimmering water) with bursts at 80Mbps when panning or zooming. Going to quality "5" reduces it to 33Mbps and quality "4" to 13 Mbps. So that's a bit coarse.

I was using it at quality "6" with an average rate of 23Mbps for a while until I realized that in some scenarios (at night with noise filtering not set too high) it was recording at 53Mbps for long periods of time, which was filling up my hard drive fast.

Using the API directly to set the maximum bit rate to say 40Mbps without the ROI, I get a maximum bit rate of 19.1Mbps, which is probably close to what I want.

If there is ever a software update it would be nice to have more control over the bit rate.

Not that I will be using it that way but could there be a problem running the camera at 53Mbps continuously (heat)?

 

[biggen]

I don't use ROI so I can't help with that. I just set the bit rate in the Encode section.

Here are my current settings for that cam. Everything looks great with these.

 

[wittaj]

ROI shouldn't be used and change to CBR instead of VBR to force a higher constant bitrate.

 

[quantum999]

My web interface limits the bit rate to 9728 (Kb/s). Both CBR and VBR set at 9728 result in a maximum bit rate of about 9Mbps out of the camera, irrespective of image content.

 

[quantum999]

OK, reducing the I frame interval from 30 to 15 allows me to increase the bit rate to 11776, but that's still quite low for my situation.

 

[wittaj]

Which browser are you using?

Some of the PTZs are browser sensitive and only Internet Explorer will show higher bitrates. One of mine only goes to 8192 in all browsers but IE.

 

[quantum999]

No difference with Chrome, Firefox, Edge or internet explorer mode in Edge.

 

[biggen]

What compression are you using? H.264 at a constant ~12mbps for a 4MP cam is pretty darn high.

Can you post an image or video of the artifacts you are seeing?

 

[wittaj]

No difference with Chrome, Firefox, Edge or internet explorer mode in Edge.

Maybe, maybe not, but with the PTZs we have seen some where Edge in IE mode didn't work as planned.

Someone came here with tons of false alerts. Using Edge with IE mode showed that SMD/MD was off, but when reluctantly pushed to try plain ole IE, guess what, it shows the MD/SMD is enabled, but it shows disabled in Edge with IE mode....

Not saying that is your issue, but it is worth a check. Might be other features you are missing using Edge with IE mode.

 

[wittaj]

What compression are you using? H.264 at a constant ~12mbps for a 4MP cam is pretty darn high.

Can you post an image or video of the artifacts you are seeing?

He mentions shimming water, and that can wreak havoc on require a ton more bitrate than a camera is capable of as it tries to resolve every nuance of the water.

 

[quantum999]

For instance, at low light at night without using excessive filtering, there is quite a bit of noise and using 12mbps is not enough to get fine details, they are just blurs. I have a few IPC-T54IR-ZE S3 and I wish I had a bit more than 16Mbps at night to get finer details in a couple of them.

It might just be me but if the camera has the capability to sustain 53Mbps, why limit it it to 11Mbps? The cheaper IPC-T54IR-ZE S3 has a higher limit.

 

[biggen]

For instance, at low light at night without using excessive filtering, there is quite a bit of noise and using 12mbps is not enough to get fine details, they are just blurs. I have a few IPC-T54IR-ZE S3 and I wish I had a bit more than 16Mbps at night to get finer details in a couple of them.

It might just be me but if the camera has the capability to sustain 53Mbps, why limit it it to 11Mbps? The cheaper IPC-T54IR-ZE S3 has a higher limit.

Noise at night could be too much gain, or too little 3D filtering, or too quick of an exposure, or all the above. We would need to see video or the very least still pictures and then screen shots of all your settings to give recommendation that isn't more than guessing.

Or it could be what you are saying and that the camera doesn't have enough bit rate to sustain the scene. I've just never heard anyone here report that with any Dahua camera I've ever seen.

 

[wittaj]

What is you shutter speed?

 

[quantum999]

I use a max of 1/60s at night. I can't currently use the illuminator because of my setup so this is only far away street lights. The 3D filtering was set to default of 50 a few days ago and I thought the image was super smooth at 11Mbps... until a couple of wolves showed up and they were quite blurry. So I reduce 3D filtering but artifacts were too high without increasing the bit rate around 20Mbps.

I realize that better lighting will solve the problem but why limit the bit rate so low?

 

[wittaj]

Yeah NR of 50 is a recipe for blur.

Lack of light is your enemy. Higher bitrate won't help that.

In fact, higher bitrate will make the noise more prominent as it tries to resolve things in the field of view.

As you have seen, we don't care about static images. We are not entering these photos to the County fair. We want clean captures of objects.

At night, you need a ton of infrared and/or visible light.

 

[biggen]

I realize that better lighting will solve the problem but why limit the bit rate so low?

Ah, this is the problem. You are trying to run color at night with low light. You need either a larger sensor or more light. No amount of bitrate will make up for either of these two things.

You are powering the camera via PoE I assume. They make PoE IR emitters. You would have to run the camera in B/W at night but you would at least get a much more useable scene than some grainy/blurry color image that isn't useful to anyone.

 

[quantum999]

I am running B/W but the problem is the same...I might add some IR emitters at some point. Here are 2 daytime images I just took, one is at over 50 Mbps the other at 11Mbps.

 

[bigredfish]

For instance, at low light at night without using excessive filtering, there is quite a bit of noise and using 12mbps is not enough to get fine details, they are just blurs. I have a few IPC-T54IR-ZE S3 and I wish I had a bit more than 16Mbps at night to get finer details in a couple of them.

It might just be me but if the camera has the capability to sustain 53Mbps, why limit it it to 11Mbps? The cheaper IPC-T54IR-ZE S3 has a higher limit.

Without a real full res snapshot we're all just spitballing ...BUT

• What are these "excessive filtering" settings you speak of?
• 10-12 Mbps is MORE than enough for a 4MP - 1/1.8 sensor camera. You wont see any difference at 30-40Mbps
• Not sure where you're measuring bps but I don't believe that camera won't run 30-40 Mbps sustained
• Raising bitrate on that camera beyond 12 Mbps wont help with detail at all nor on the 54IR-ZE-S3
• If you're trying to run in color at night, you don't likely have enough light to do that. You would need a LOT more light than you think to get clear, no-blur, moving target, color images. It's rare for that camera/sensor to be able to run good color at night
• Min exposure needed to freeze (no or min blur) even slow moving targets like humans is 1/120 or 0-8.33 with DNR around 40. Shutter speed and DNR make the difference on clarity if an image with a moving target
• As mentioned, ROI is kinda useless, especially using the entire screen * There is a minor difference at 10MB but I'm not seeing much diff at max bitrate
• Also as mentioned, the rest of your settings can well make a difference and its impossible to help you focusing on one thing like bitrate without knowing the rest of the settings

 

[bigredfish]

I am running B/W but the problem is the same...I might add some IR emitters at some point. Here are 2 daytime images I just took, one is at over 50 Mbps the other at 11Mbps.

Those are about 1.3MB images. Very small or compressed. Are they from your substream?

Normal 4MP jpg image from main stream, running 8-10 Mbps is 3-5MB

 

[quantum999]

Yeah, those are screen capture from UI3, the difference is visible. I can upload full resolution picture if you think that will help. The camera seems to struggle at over 65Mbps, I take the bit rate from here: