How to subscribe to Nx motion events on a camera

Answered

Permanently deleted user

October 06, 2020 10:52

Hi,

How can I programmatically subscribe to motion events on a camera so that I can detect motion events when some motion detected.

Thanks

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• Official comment

  

  Norman

  • Network Optix team

  October 06, 2020 12:06

  Hi @...,

  Can you describe the steps a bit more about what you want to achieve? 

  To enable or disable a rule, the saveEventRule part of our server API should enable you to create such thing. 

  Some more information can be found in THIS support article. 

   
• 

  Permanently deleted user

  October 06, 2020 12:11

  Hi Norman,

  I want to achieve the following 

  1. A program to listen motion events from a camera

  2. Once motion is detected, the program can get notified and it can trigger a recording and do its own logic 

  In a nutshell, I want to listen motion events from Nx camera and do my own logic when a motion is detected

  Regards

  Sebastian

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• 

  Norman

  • Network Optix team

  October 08, 2020 08:37 Edited

  Hi @....

  I would set up a rule as follows: 

  Event = Motion Detection ⇾ Action = Send HTTP event

  When your program receives the HTTP event, and your logic has been meet, follow the suggestions in the support article I linked to in my previous response. 

  Also, please check the following support articles which might be useful for your use case: 

  • How to start/stop the recording schedule of a specific camera via Nx Witness Server API
  • How to start/stop recording using Nx Witness Generic Event
  • API Tip: Video Footage Export

  1
• 

  Permanently deleted user

  October 08, 2020 08:38

  Thanks 

  0
• 

  Permanently deleted user

  October 08, 2020 12:58 Edited

  Hi Norman

  How can I pass the camera Id to the http endpoint from the event rule ?

  Do you have any samples for that

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• 

  Norman

  • Network Optix team

  October 08, 2020 14:13

  Hi @...,

  The best practice would be to create two rules in this case. 

  1. Event = Motion Detection ⇾ Action = Send HTTP event (1)

  2. Event = Generic Event -> Action = Send HTTP event (2)

  The first HTTP event that is sent, is sent (and received) to the Nx Media Server itself. The second HTTP event is sent to your application. 

  Example URL, please check the server API for the createEvent section for more information: 

  http://<serverIp>:<port>/api/createEvent?source=<uniqueSource>caption=<uniqueCaption>&metadata={"cameraRefs":["cameraId"]}
  

   

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• 

  Permanently deleted user

  October 09, 2020 02:36

  Hi Norman,

  Thanks for the reply. I still didn't understand how my custom HTTP end point receives camera id dynamically

  Do Nx have some token which will be replaced at runtime ?

  for example

  http://localhost/my-event?cameraId={cameraId}&eventname=XXXX&....

  This endpoint I want to configure as the target action of the motion event rule

  or else I configure different rules for each camera and hardcode the cameraId ?

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• 

  Andrey Terentyev

  • Network Optix team

  October 09, 2020 14:32 Edited

  
  Hello Sebastian,

  > I still didn't understand how my custom HTTP end point receives camera id dynamically
  > Do Nx have some token which will be replaced at runtime ?
  Yes, it does.

   

  The approach is:

  1. For each camera you create a rule for detecting a motion on the camera.

  The action should be "Do HTTP Request" triggering Generic Event.

  For example,

  http://<serverIp>:<port>/api/createEvent?source=cameraId&caption=motion

  cameraId - is the ID of the camera
  caption or description parameter can be used for storing a sting-tad distinguishing generic event type.

  Of course, you can create this bunch of rules over API with /ec2/saveEventRule

  
  2. You create one Generic Event rule.
  The action should be "Do HTTP request" to the URL of your system

  http://localhost/my-event?cameraId={event.source}&eventname={event.caption}&someparam={event.description}

  {event.source} - would be automatically replaced by the Generic Event's source field value
  {event.caption} - would be automatically replaced by the Generic Event's caption field value
  {event.description} - would be automatically replaced by the Generic Event's description field value

  Please, have a look at these threads for details.
  https://support.networkoptix.com/hc/en-us/community/posts/360042988034-How-to-use-execHttpRequestAction-and-it-complete-functionality
  https://support.networkoptix.com/hc/en-us/community/posts/360043672414--api-executeEventAction

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• 

  Permanently deleted user

  October 12, 2020 08:27 Edited

  Hi Norman,

  Thanks for the explanation. 

  Now my question is if I bind "Do HTTP Action" with following url directly to a motion event  instead of generic event, will it work ?

  http://localhost/my-event?cameraId={event.source}
  
  

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• 

  Andrey Terentyev

  • Network Optix team

  October 12, 2020 12:34 Edited

  Hello,

  It won't.

  But if you have a lot of cameras you could automate creation of motion detection rules by a script.

  1. You invoke gatCemerasEx for getting the list of cameras.

  2. You iterate through the list of cameras and create a motion detection rule per camera with /ec2/saveEventRule

  Since you have all the info about a camera (cameraId, model etc.), you could create a rule having exact URL in the "Do HTTP Request" action. For example,

  http://localhost/my-event?cameraId=<cameraId taken from the list>&eventname=<your tag for motion detection>&someparam=<another specific parameter value>

   

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• 

  Permanently deleted user

  October 13, 2020 04:39

  Hi Andrey,

  Thanks for the clarification. It is clear now

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