Question about video delay when displaying object bounding box in NX Client.

Answered

Permanently deleted user

May 16, 2022 09:09 Edited

hello.

I have a question about video delay when displaying object bounding box.

After selecting "Show on item" - "objects" in our plugin to display the object bounding box, there was a video delay of 1.5 to 2 seconds.

As a result of checking whether there is a delay in the sample plugin (sample, stub), it was confirmed that there was a slight delay in the sample plugin and 1.5 to 2 seconds in the stub plugin.

To check if there is a problem with drawing the object box, I randomly drew 1 to 1000 boxes and tested it, but regardless of the number, there was a delay of 1.5 to 2 seconds.

And when the network condition is bad, when the bounding box is displayed, the delay continues and sometimes a delay of 5 seconds or more occurs.

I would like to know why the delay is occurring. Is there a way to further reduce the video delay?

Additionally, I would like to know the difference between the logic of displaying the object bounding box and not.

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  Tagir Gadelshin

  • Network Optix team

  May 17, 2022 14:21

  Hi @...

  Which version do you use? We tried to fix this issue in 5.0. You can test it in our latest Nx Meta release: https://meta.nxvms.com/downloads/betas

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  Permanently deleted user

  May 18, 2022 00:09

  Here are the versions:
  Nx Client: 4.2.0.32836 R4
  Nx Server: 4.2.0.32843
  Metadata SDK: 4.2.0 R4

  thank you.

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  Andrey Terentyev

  • Network Optix team

  September 14, 2022 12:55

  Hello jeongho kim,

  To check if there is a problem with drawing the object box, I randomly drew 1 to 1000 boxes and tested it, but regardless of the number, there was a delay of 1.5 to 2 seconds.

  This delay is expected. It is being introduced by the Server to rearrange metadata packets to be saved together with the frames the metadata packets were generated for.

  This is delay in terms of timestamps of the video stream being processed. That means, if the metadata arrives at the client with the delay greater than 2 s comparing to the timestamp of the frame being displayed in live stream, the corresponding bounding box won't be displayed in the GUI.

  I would like to know why the delay is occurring. Is there a way to further reduce the video delay?

  Here are articles describing metadata flow.

  https://support.networkoptix.com/hc/en-us/articles/360023747914-2-Integration-Architecture-Understanding-Plugins

  https://support.networkoptix.com/hc/en-us/articles/360058902133-Analytics-Logs-Monitoring-Metadata-Flow

  Generally, the most delay is introduced by the plugin while processing video frames.

  To answer your question, could you please elaborate on what delay exactly do you mean?

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