Weird i-frame linked artifacting in videos

T

T-Dawg

n3wb
Apr 3, 2015
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Hi folks,

Just got a new 2CD2632F and very happy so far... but noticed that there is a strange artifacting going on every so often in the video, the interval seems to be linked with the iframes

Uploaded a sample video here: (probably worth viewing in 1080p, you can see the effect every second or so)

You'll see that video artifacts kind of accumulate briefly, then the iframe resets the picture back to full clarity. But it's a very jarring effect and can make you feel sick when watching videos for more than a few minutes...

I've tried playing with almost every video/image setting I can think of, and while extending iframes out to only once every 250 frames reduces the frequency of the issue, it still happens...

Anyone got any tips on what's causing this and how to fix it?

Edit: Video settings might be useful...:
15me3o7.png
 
Last edited by a moderator:
T-Dawg said:
Hi folks,

Just got a new 2CD2632F and very happy so far... but noticed that there is a strange artifacting going on every so often in the video, the interval seems to be linked with the iframes

Uploaded a sample video here: https://youtu.be/9ECgheH7Xp0 (probably worth viewing in 1080p, you can see the effect every second or so)

You'll see that video artifacts kind of accumulate briefly, then the iframe resets the picture back to full clarity. But it's a very jarring effect and can make you feel sick when watching videos for more than a few minutes...

I've tried playing with almost every video/image setting I can think of, and while extending iframes out to only once every 250 frames reduces the frequency of the issue, it still happens...

Anyone got any tips on what's causing this and how to fix it?
Click to expand...
Welcome to the forum..instead of increasing your iframes, match your iframe to you frames per second.
 
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fenderman said:
Welcome to the forum..instead of increasing your iframes, match your iframe to you frames per second.
Click to expand...

Thanks fenderman :-)

Matching the iframes to fps was actually one of the first things I tried, read that somewhere else too. In the example video, the iframe interval is set to 30 with recording at 30fps, which gives the effect every second :-(
 
T-Dawg said:
Thanks fenderman :-)

Matching the iframes to fps was actually one of the first things I tried, read that somewhere else too. In the example video, the iframe interval is set to 30 with recording at 30fps, which gives the effect every second :-(
Click to expand...
Set the bitrate to constant and video quality to high...is the camera wired to your network?
 
Tried this too, set bitrate to constant, video quality to high and cranked the bitrate up to 4096kbps, doesn't seem to make any difference

Camera is indeed wired

Video with constant bitrate:


using these settings:
29q0gvc.png
 
Have you tried placing it out side, or indoors but not facing a window with reflection?
 
T-Dawg,

4096 Kbps is not high for 1080p video at 30 FPS. Try doubling it again (8192) and see if that looks better.

Also, your video encoding may be more efficient if you set it back to Variable bit rate and choose the highest quality option instead of Medium.

The way Variable bit rate encoding works, you choose a quality level that is "good enough" for you, and the camera does its best to reach that quality level without making the stream exceed the Max Bitrate. Often, your chosen quality level can be reached without using all the available bit rate and the result is that video with little to no motion will not waste bandwidth unnecessarily.

Constant bit rate simply encodes at the Max Bitrate always, making the file size and bandwidth usage more predictable. But it also does not allow the video encoder to save bandwidth when it can do so without harming image quality.
 
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Thanks for all these very useful tips! Really good learning points, explains a lot.

I've tried camera both indoors and outdoors without the window (it's just in front of the window temporarily until I get my wall mount sorted) - still the same problem

I've been playing around with image quality a little more (did a full factory reset first to make extra sure I hadn't changed something obscure)... I think it's a little better with 8192kbps highest quality VBR, as well as turning the fps down a little to 25fps and syncing the iframe interval accordingly

Also tried switching between 50 and 60hz (we're 50hz mains here), but not sure if that makes much difference...

Like I said, I think it's a little better... but I still think I can see a flashing type effect on the grey road areas every second. BUT I've been staring at my screen for so long now that I'm not sure if I trust my eyes any more, I could just be seeing things at this point :-)

VBR@8192kbps/25fps:


settings:
m7d.png
 
It is still happening. It is subtle.

It might be less pronounced with the iframe interval being 2-3 times the frame rate, as i-frames use up a large amount of the bit rate so having them less frequently will leave more data for the other frames. Lower frame rate also will help. Like with my cams at 6 FPS I don't notice the effect at all, but motion is far from smooth...
 
bp2008 said:
It is still happening. It is subtle.

It might be less pronounced with the iframe interval being 2-3 times the frame rate, as i-frames use up a large amount of the bit rate so having them less frequently will leave more data for the other frames. Lower frame rate also will help. Like with my cams at 6 FPS I don't notice the effect at all, but motion is far from smooth...
Click to expand...

Yeah I think I'll bump the iframe interval back up a bit (I've noticed it sometimes hangs on the iframes as well with the extra data burst so it'll help that too) and play around with the frame rate to see what the optimal frame rate for me is

Is this pretty standard behaviour for the Hikvision cams? Haven't noticed it on other cheaper cams but then those haven't been high enough resolution to really notice, this is my first HD camera
 
I've seen it on any camera with high frame rate, even my old Ubiquiti AirCams which are 1280x720 running at 30fps with 4000 Kbps bit rate. But due to necessity (keeping CPU usage under control in Blue Iris) I have been reducing my frame rates to 3-6 FPS. The PTZ cameras get 10 FPS. At these lower frame rates I find the quality does not shift much between frames.
 
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Ah, that certainly explains it too. Bit more playing and tweaking required on my set up to get the right balance, but dropping down to 25fps certainly helps reduce the effect without really losing too much motion sensitivity

All part of the learning experience, thanks again for the pointers :-)
 
I did not look at the video but if it's what I think it is (pulsing every I-frame), for a H* turn the noise reduction to 11. I think that takes care of it. The main cause I believe is that encoding quality on all IP cameras (that I have, at least) is poor; even jacking up the bitrate won't matter since it's not a matter of bits, but of time (for the camera to do the job in real time) -- it has to take short cuts.

As a simple, easy-to-grasp test case: look at HD TV. That's 1920 x 1080. Crystal clear image. Your IP camera, whatever super-HD it may be, doesn't come close. If your TV image was as bad as your IP camera's you'd cut the cord for sure.
 
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40th Floor said:
I did not look at the video but if it's what I think it is (pulsing every I-frame), for a H* turn the noise reduction to 11. I think that takes care of it. The main cause I believe is that encoding quality on all IP cameras (that I have, at least) is poor; even jacking up the bitrate won't matter since it's not a matter of bits, but of time (for the camera to do the job in real time) -- it has to take short cuts.

As a simple, easy-to-grasp test case: look at HD TV. That's 1920 x 1080. Crystal clear image. Your IP camera, whatever super-HD it may be, doesn't come close. If your TV image was as bad as your IP camera's you'd cut the cord for sure.
Click to expand...

Ah ha... very interesting! Indeed, exactly what you're thinking, pulsing on every I-frame

This certainly matches up with it pulsing even more during low light/night shots without IR too... NR obviously working harder to compensate for the masses of low light noise

I'll try playing with the NR levels, starting at 11, see how we get on... (currently set to the default of 50)
 
40th Floor said:
11 is a reference to an old movie. Set it up all the way (100).

A lot of cameras do this by the way.
Click to expand...

Haha, I was thinking 11 was a bit random :laugh: Completely missed the joke

Tried turning it down and off but no effect. Cranked it up to 100 (before I saw your last post) and have left it there since, as well as extending the iframe interval out to 250 (@25fps, so every 10 secs) on the main stream, this seems to be the best blend for recorded footage I've found

For live monitoring I've left the secondary stream with an interval of 25 @ 25fps (every sec) since I'm not as bothered about the flashing on a smaller screen, need the lower interval to let it get the initial stream picture quicker (since it can be up to an iframe interval wait to get it)

Think that'll be about as good as it gets... and the extra NR on low-light night shots looks better too, cleans the image up quite a bit
 
I've been having the same issue as OP lately, but with a 2CD2032-I and I tried every suggestion on the web with no dice. One last thing I tried was downgrading my firmware and lo and behold, that solved it. So in my case, the problem was the 5.3 firmware. I went back to 5.2.3 (latest official pre-5.3 firmware available) and the issue went away completely. As a bonus, my noise levels were even lower with the same settings.

So for anyone experiencing this, try changing the firmware, because I believe this is definitely a bug.
 
Most of my Hiks are running 5.1.6, and they all exhibit this behavior. I find the pulsing in the video to be much less disturbing to me personally if I set the I frame rate to twice the frame rate, so that the pulses are 2 seconds apart.
 
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