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D455 Screen Tearing/Flickering Issue

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Mau

Hi, 

We are using a D455 for a video analytics project, its a great camera, however we are experiencing an unusual issue where sometimes the video feed gets corrupted and the screen seems to be stuck on a past frame and flickers between this past frame and the current ones. 

We are able to reproduce the issue fairly well, and it seems to only happen when we run the camera at 15fps or more. When we set it at 5fps there seem to be no problem. 

 

I am attaching a short video of the issue. Hope someone has already encountered the same issue and can help. 

https://drive.google.com/file/d/1zweomikc9TORqMlAEH08pvRMkMnYKC8i/view?usp=sharing


Camera: D455

FW version: 2.47.0

USB Cable: 3 meters USB 3.0 cable https://www.amazon.com/gp/product/B083JQR7TR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Computer: NVIDIA Xavier AGX

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3 comments

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  • MartyG
    • Edited

    Hi @Mau  I performed a frame by frame analysis of the video.  It is alternating rapidly between two completely different scenes. 

    Looking carefully at the two images as they flicker, it can be observed that both the red-mountain and truck scenes are trying to play at the same time, so it is like two different movies that are being played simultaneously.

    I have seen cases where 2/3 of the image is the current frame and the final 1.3 slice of the image an older frame, but not a flicker back and forth like this.

     

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  • Mau

    Thanks for the prompt response MartyG and for analyzing the video. What you are saying is interesting two frames competing for the screen, however since it is just one camera, one of the frames must be from the past and it is stuck?.

    I was thinking it had something to do with the camera buffer being overloaded (at 15fps or more). Still not sure what could be causing this. I did see some older posts talking about the autoexposure not sure if that has anything to do with it.

    Even if you don't know the answer, I would appreciate if you could share any thoughts you may have, and I will gladly investigate as it is a critical issue since the feed is being processed downstream for video analytics. 

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  • MartyG
    • Edited

    RealSense cameras do not have internal frame buffering in their hardware and so buffering takes place on the computer / computing device, as described in the RealSense SDK's Frame Buffering documentation.

    https://github.com/IntelRealSense/librealsense/wiki/Frame-Buffering-Management-in-RealSense-SDK-2.0#latency-vs-performance

     

    If you are only capturing one stream (RGB video) and not an additional stream such as depth then the default buffering settings (a frame queue size value of '1') should be sufficient though.  If you are using 640x480 resolution (as displayed in the top corner of the image) then this capture should not be imposing a heavy processing burden on the computer.  Can you confirm please if the RGB capture resolution is 640x480.

     

    Also, is the camera plugged into a USB 2 or a USB 3 port on the computer?  USB 2 connections are slower and limit the camera's capabilities compared to a USB 3 connection.  Intel have published a guide about this in the link below.

    https://www.intelrealsense.com/usb2-support-for-intel-realsense-technology/

     

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