Intermittent Pixelated video capture

K

kwanfam

n3wb
Jun 21, 2014
7
0
Orange County, California
Hi, I have a pixellated video capture from time to time, and don't know why. It happened on all three of my IP cameras Dahua 2MP HDB3200CN, 2MP HFW3200S, and 1.3 MP HFW 2100S on an intermittent basis. It will be fine then become pixellated for maybe a second and then go back to normal.

I am running BI on a laptop with Intel i5 4200 CPU, 8GB RAM, onboard Intel Graphics 4400 and 240 GB Seagate SSD. The bitrate is about 1K, at 30 fps, buffer at 30. On the record function, there is no encoding to save on the CPU processing, and the video going direct to the SSD. The CPU runs between 45% to 80% during normal operation including when triggered. Once in a while the CPU goes past 90%, but I have not been able to see the CPU usage at the time of the pixellated capture. I tried changing the settings, but slowing the fps seems to make it worse, but I am not sure if the two are related.

I would upload a sample, but I not sure how to upload a MP4 clip, its about 300KB.

Your thoughts would be appreciated.
 
You can upload to youtube then post. Try matching the i-frame interval to the frame rate to see if that helps.
 
The video is private so we cant see it. You need to log into the camera directly via web browser.
 
That is a very common glitch in h264 streams, and there is no single solution for it.

Some things to try would be a higher bit rate and making the i-frame interval match the frame rate.

Does this also happen in live views or only in recordings?

Upgrading the firmware might help as well, as this might bring updates for the h264 encoder.
 
bp2008 made some good points. I have the 3200cn in one location and had the exact same issue. The only remedy was to disable recording to the SD card. That was causing my problem. As far as the others that dont have sd cards, the i-frame interval may help. Newer firmware is always a good try when you have issues like this. If someone has the newest firmware for the 3200cn i would love a copy.

 
Hi, I don't notice it in the live stream, but I don't recall seeing the live stream when this occurs. At the camera, the bit rate is 8192 , i interval is 30, fps is 30, resolution is 1080P, bit rate type is CBR, and encoding is H.264

There is also an option for encoding with H.264B. Would that make a difference? I tried updating the firmware but like other Dahua products the later versions often have other bugs that can make things worse. Thanks for your help
 
Not a subject that I'm well versed in, but I can offer one of my experiences to see if it is relevant to the topic. I attempted recording directly to disk on one of my systems that was loading up the CPU, and also causing a delay between realtime and whats actually on the screen. The result was pixelated images, ghost images, and some psychedelic visual effects. Moral of the story is, if you are recording directly to disk, try to switch it up and see if the result is the same or different.
 
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