2332 Weird "pulse"

[x3d33x]

Hi everyone!

I just got my first Hikvision camera (2332 5.2) all set-up. Now I'm thinking I have a bad cam.

I've noticed in Blue Iris and directly from the camera it has this weird "pulse" The image goes from crystal clear and starts to get 'fuzzer' and then a quick flash of black and then all clear again. This happens very quickly, like within a second or 2. The camera is still useable and looks fairly good. But this is driving me nuts, I have tried every setting, I tested the network cable. I'm at a lost. Anybody have any ideas?

This seems to be more profound when in 3mp vs 1090p. Currently frame rate and I frame are both set to 20.

Thank you,
x3d33x

 

[corkangel76]

does it pulse while in live view via web browser too?

 

[x3d33x]

yes it does

 

[corkangel76]

Try dropping your frame rate to 20fps with a 4096 buffer and see if that solves it?

 

[x3d33x]

By buffer do you mean max bitrate? That doesn't seem to help any

 

[corkangel76]

yup, 20fps, max bitrate of 4096, have you also verified KNOWN GOOD cables?

 

[x3d33x]

I have not. I'll have to try that tomorrow. I don't have another long cable so I'll have to unmount the camera to check.

 

[fenderman]

I have not. I'll have to try that tomorrow. I don't have another long cable so I'll have to unmount the camera to check.

This is common, usually not very noticeable...this is because the camera does not send a complete frame all the time...to minimize the effect, lower the iframe interval to match your fps...
Post of video of what is occurring..

 

[x3d33x]

Here is a video.. youtube processing cleaned it up a lot... but if you stare at the grass you can kind of see where it blurs, flashes, looks clean then repeats. Its like it keeps losing focus



iframe and fps is set to 20

 

[Razer]

Set iframe to 1. That will fix it. It is more noticeable in some shots than others, I usually match the iframe to my FPS, but I am doing 8-10 FPS usually. iframe of 1 will make for more data in the shots and bandwidth will go up, but it will fix what you are seeing.

 

[digger11]

Hi everyone!
Currently frame rate and I frame are both set to 20.

I think you'll find that if you change the I Frame Interval to 40 you will see the pulses go from once per second to once per two seconds.

I've seen the exact same behavior with my Hikvision cameras, and it bugged the heck out of me. Changing my settings so that the camera is sending I Frames ever two seconds reduced the pulsing to a point that I can sort of ignore it.

 

[bp2008]

I've been seeing this for years with h264 cameras. Each pulse begins when an iframe is decoded and displayed. Then the following frames clean up the image little by little until the video reaches peak quality, but the next iframe undoes all that quality buildup and causes quality to be reduced again.

In some cases, this causes a distracting visual effect as you have noticed. There are a few things you can do to reduce or eliminate this effect.

1. Increase the bit rate. Higher bit rate means more data can be allocated to each frame, so the quality is higher. Unless you are short on network bandwidth or disk space, there is little reason not to max it out.

If that isn't enough to adequately solve the problem, there are more steps you can take.

2. Increase the iframe interval. I-frames are huge, and take up a very significant amount of the total bit rate. A higher interval means fewer iframes, which means the bit rate gets spread around better.
3. Reduce the frame rate. Again, with fewer frames, there is more data left over for the other frames.
4. Reduce the image resolution. This is a last resort because you are sacrificing detail to make the remaining detail look better.

You can try any or all of these things, but the underlying problem is that your iframes are being encoded at less than ideal quality and you need to improve that to reduce the pulsing effect.

(I would not recommend setting the iframe interval to 1. If the encoder even honors such a request, it will mean a tremendous reduction in compression efficiency and almost certainly a lower quality image.)

 

[x3d33x]

Hmm I maxed the bit rate and set the I-frame to 40 and it seems to be much better. Its using 1500kbps, my network is fine with that, but now I'm afraid of recording LOL

I tried to set the I-frame to 1 and the quality of the video was terrible.

Thanks so much for the help guys. I think I can live with the current settings.

 

[digger11]

Here is Hikvision's technical bulletin with their recommended bit rates: http://oversea-download.hikvision.com/uploadfile/doc/20140512/IP Camera Recommended Bitrate v2.0_20140219.pdf

 

[Razer]

Hmm I maxed the bit rate and set the I-frame to 40 and it seems to be much better. Its using 1500kbps, my network is fine with that, but now I'm afraid of recording LOL

I tried to set the I-frame to 1 and the quality of the video was terrible.

Thanks so much for the help guys. I think I can live with the current settings.

Ha, yes, with iframe at 1 you may well have to double your bandwidth to the camera as it really amps up the data coming in from the camera!