Occasional weird smearing image in recordings


#1

I only have this issue occasionally with one of my newer cams, but figured I’d ask. Sometimes, when I pull up the live feed or the resulting recording in NCS, the image is like a smeared painting. It’s hard to describe. Sometimes, the entire video will be smeared, and sometimes the entire video will be black except for where motion is detected, and you just see the motion detected object streak across the video while everything else stays black.

Like I said, it’s hard to describe, but here’s an example:

When it’s happening, if I open the live stream to the same camera using a browser or VNC, I don’t see the same issue. I can have a browser and NCS side by side at the same time, and I only see the issue in NCS.

It’s not a huge deal, and it’s only happened a few times over the course of the last month, but I figured it was worth posting. I’m not sure if it’s something with ffmpeg or what.


#2

Hi!
Yes, I understand what this is about. The bitstream from the camera must be in an exact way so that the decoder in NCS can interpret the stream correctly to a video. If that bitstream is altered for some reason the resulting video can be black or smeared or lose color or something else. If the communication is using TCP/IP small problems in the communication is corrected for since the bitstream is re-transmitted. However, in real-time system this can also cause an irregular video.

The video you see in NCS, browser and VNC most likely do not use the same bitstream. How is the camera connected to NCS? Is it with mjpeg, rtsp or mp4 or … If the cam use h.264 and you connect it with rtsp it is very important that the whole chain works correctly.

Since there is no problem in the browser and VNC the communication between camera and computer is probably fine. You mention that you have this problem only with the new camera I would check if it might be an update of the firmware available for the cam.

Depending on the camera you can try to use another protocol and see if that makes it better.

-Henrik