MV Presence Analytics

Line crossings and people/vehicle counts

Line crossing data events will be delivered for all configured crossing lines over MQTT in the following format:

TOPIC /merakimv/<serial-number>/crossing/<uuid>
{
  "_v" : 1,
  "label" : "crossing_line_1",
  "event" : "crossing_in|crossing_out"|"expired"|"appeared",
  "object_id" : 123,
  "type" : "person|vehicle",
  "ts" : 1663779000000
}

The uuid will map to the generated uuid a configured crossing line or area is given when created. Vehicle counting is only available for non-fisheye cameras.

Occupancy data

Occupancy data will be pushed to the configured MQTT recipient every (wall clock) minute and will contain the positions for all objects that have occupied the space during the minute starting at ts and ending at ts+60 seconds. When a track no longer has overlapping time for the current period it will no longer be included in the list. Object_ids in this payload can be matched with what is sent for this area on the crossing topic above.

TOPIC /merakimv/<serial-number>/occupancy/<uuid>
{
  "_v" : 1,
  "label" : "area_51",
  "objects" : 
  [
     { "object_id": 12,
       "type" : "person",
       "ts_entered" : 1678971542000,
       "ts_appeared" : 0,
       "ts_exited" : 0,
       "ts_expired" : 0
     },
     { "object_id": 13,
       "type" : "person",
       "ts_entered" : 1678971548000,
       "ts_appeared" : 0,
       "ts_exited" : 1678971620000,
       "ts_expired" : 0
     },
     { "object_id": 17,
       "type" : "vehicle",
       "ts_entered" : 1678971621000,
       "ts_appeared" : 0,
       "ts_exited" : 0,
       "ts_expired" : 1678971641000
     },
     { "object_id": 18,
       "type" : "person",
       "ts_entered" : 0,
       "ts_appeared" : 1678971621000,
       "ts_exited" : 0,
       "ts_expired" : 1678971641000
     }
  ],
  "ts" : 1678971600000
}

Note that vehicles will not be supported by the fish-eye cameras.

The live data for areas will be pushed on the crossing topic in a similar fashion as people and vehicle counts are for crossing lines with the only exception that you can receive events with directions "expired" and “appeared” as well. These events are sent when a tracked object is lost/timed out or discovered/appeared within an area.

TOPIC /merakimv/<serial-number>/crossing/<uuid>
{
  "_v" : 1,
  "label" : "area_51",
  "event" : "crossing_in"|"crossing_out"|"expired"|"appeared",
  "object_id" : 123,
  "type" : "person|vehicle",
  "ts" : 1663779000000
}

The live crossing data stream is only available to a client over MQTT, while the data sent on the occupancy topic will also be available from the internal and external API's.

Tracks payloads

Track data will be pushed whenever a track has expired/is lost, one push per track. This functionality has to be enabled specifically per camera. The timestamp is set to when the track expired and the positions is an array of estimated feet positions for the track in the interval interval_ms milliseconds:

TOPIC /merakimv/<serial-number>/tracks
{
  "_v" : 1,
  "interval_ms" : 500,
  "positions" : 
  [
    [
      0.48191,
      0.64122,
      1657849000
    ],
......
    [
      0.48367,
      0.5828,
      1657847500
    ]
  ],
  "object_id" : 123,
  "ts" : 1657849000
}