Deepstream-4.0.1 Altering nvmsgconv and nvmsgbroker

Hi,
i have Deepstream pipeline as follows:

!pgie || !nvtracker || !sgie1 || !sgie2 || !sgie3 || !tiler || !nvvidconv || !nvosd || !msgconv || !msgbroker || !tee || !queue1 || !queue2 || !sink

What I can see is that the message broker sends the message to the server for each frame. For example,

{
  "FrameID" : 570,
  "@timestamp" : "2019-11-14T05:55:19.647Z",
  "sensorId" : "0",
  "ObjType" : "Person",
  "object" : [
    "438|475|462|533|Person",
    "438|475|462|533|Person",
    "63|440|192|798|Person",
    "60|434|192|800|Person",
  ]
}

What I want is to generate and send a message for each object detected. How can I achieve that?
I want the messages to be like this:

{
  "FrameID" : 1438,
  "@timestamp" : "2019-11-14T06:28:51.591Z",
  "sensorId" : "0",
  "ObjType" : "Person",
  "topleftx" : 417,
  "toplefty" : 475,
  "bottomrightx" : 441,
  "bottomrighty" : 542
}
{
  "FrameID" : 1439,
  "@timestamp" : "2019-11-14T06:28:51.607Z",
  "sensorId" : "0",
  "ObjType" : "Person",
  "topleftx" : 414,
  "toplefty" : 475,
  "bottomrightx" : 438,
  "bottomrighty" : 542
}
{
  "FrameID" : 1440,
  "@timestamp" : "2019-11-14T06:28:51.635Z",
  "sensorId" : "0",
  "ObjType" : "Person",
  "topleftx" : 414,
  "toplefty" : 475,
  "bottomrightx" : 438,
  "bottomrighty" : 542
}