Get tracks using GO

To get tracks using GO, do the following:

1. Install GO (see Go programming language).

2. Run the code example:
   

   Code example:

   client := metadata.NewMetadataServiceClient(conn)
   
   stream, err := client.PullMetadata(context.Background())
   ch := make(chan int, 8)
   
   go func() {
     for {
       in, err := stream.Recv()
       if err == io.EOF {
         close(ch)
         return
       }
   
       if err != nil {
         log.Fatal(err)
       }
   
       switch data := in.Data.(type) {
         case *metadata.PullMetadataResponse_Heartbeat:
         //
         case *metadata.PullMetadataResponse_ConfigUpdate:
         //
         case *metadata.PullMetadataResponse_Sample:
         switch sampleData := data.Sample.Data.(type) {
           case *metadata.MetadataSample_Tracklets:
           log.Printf("Time: %v\nTracklets: %v", data.Sample.Timestamp, sampleData.Tracklets)
         }
       }
   
       ch <- 1 // notify the main thread about receiving the sample
     }
   }()
   
   endpoint := media.EndpointRef{AccessPoint: "hosts/SERVER/AVDetector.1/SourceEndpoint.vmda"}
   req := metadata.PullMetadataRequest{
     Count:                 8, // ask for several samples, so that they are not lost while server waits for another response from client
     Endpoint:              &endpoint,
     ProposedChannelIdleMs: 15000,
   }
   
   if err := stream.Send(&req); err != nil {
     log.Fatal(err)
   }
   
   for {
     // whenever a sample is received ask for another sample keeping the total samples requested to a fixed value > 1
     <-ch 
     req := metadata.PullMetadataRequest{
       Count: 1,
     }
   
     if err := stream.Send(&req); err != nil {
       log.Fatal(err)
     }
   }

As a result, you will get the possible response options.

Response examples:

{
  "sample": {
    "timestamp": "20230914T133656.981000",
    "tracklets": {
      "tracklets": [
        {
          "id": 70,
          "state": "OBJECT_STATE_NORMAL",
          "rectangle": {
            "x": 0.10248079895973206,
            "y": 0.3568287789821625,
            "w": 0.17517775297164917,
            "h": 0.257714182138443
          },
          "logicalCenter": {
            "x": 0.19006967544555664,
            "y": 0.6145429611206055
          },
          "color": {
            "hue": 222.47191011235952,
            "saturation": 0.3093524946210368,
            "value": 0.49719319611902735
          }
        }
      ]
    }
  }
}

where

• timestamp—time corresponding to the video frame for which tracks are formed;
• tracklets—list of tracks.

{

  "heartbeat": {}

}

{
  "configUpdate": {
    "maxChannelIdleMs": 15000
  }
}