Add System Timestamps to Metadata

This tutorial will help you add a timestamp to the metadata of each frame. This tutorial shows how to use the GST element timecodestamper that adds timestamps to frames.

Steps

1. Update default config.json present at [WORKDIR]/edge-ai-libraries/microservices/dlstreamer-pipeline-server/configs/default/config.json with below configurations.

   Update “pipeline” variable as follows

   "pipeline": "{auto_source} ! decodebin ! timecodestamper set=always ! videoconvert ! gvadetect name=detection model-instance-id=inst0 ! queue ! gvafpscounter ! gvametaconvert add-empty-results=true name=metaconvert ! gvametapublish name=destination ! appsink name=appsink",
   

   NOTE: Make sure that proprety set of timecodestamper is set to always. The timecodestamper element follows SMPTE format of storing data (hours:minutes:seconds:frames).

   set property can have anyone of the 3 values shown below

   Value	Description
   never	Never set timecodes
   keep	Keep upstream timecodes and only set if no upstream timecode
   always	Always set timecode and remove upstream timecode

   Ensure that the changes made to the config.json are reflected in the container by volume mounting it as mentioned in this tutorial

2. Start the DL Streamer Pipeline Server

   cd [WORKDIR]/edge-ai-libraries/microservices/dlstreamer-pipeline-server/docker/
   docker compose up
   

3. Open another terminal and run the following curl command to start the pipeline.

   curl http://localhost:8080/pipelines/user_defined_pipelines/pallet_defect_detection -X POST -H 'Content-Type: application/json' -d '{
       "source": {
           "uri": "file:///home/pipeline-server/resources/videos/warehouse.avi",
           "type": "uri"
       },
       "destination": {
           "metadata": {
               "type": "file",
               "path": "/tmp/results.jsonl",
               "format": "json-lines"
           }
       },
       "parameters": {
           "detection-properties": {
               "model": "/home/pipeline-server/resources/models/geti/pallet_defect_detection/deployment/Detection/model/model.xml",
               "device": "CPU"
           }
       }
   }'
   

4. To view the metadata, open another terminal and run the following command.

   tail -f /tmp/results.jsonl
   

   You should see an attribute called system_timestamp in the metadata of each frame. Sample output of a metadata from one frame shown below.

   {"objects":[{"detection":{"bounding_box":{"x_max":0.37195673026144505,"x_min":0.02789940871298313,"y_max":0.7120070457458496,"y_min":0.17735711733500162},"confidence":0.9217351078987122,"label":"box","label_id":0},"h":257,"region_id":2319,"roi_type":"box","w":220,"x":18,"y":85},{"detection":{"bounding_box":{"x_max":0.17977098003029823,"x_min":0.06219940260052681,"y_max":0.42195435365041095,"y_min":0.3419050375620524},"confidence":0.9094383120536804,"label":"shipping_label","label_id":1},"h":38,"region_id":2320,"roi_type":"shipping_label","w":75,"x":40,"y":164}],"resolution":{"height":480,"width":640},"system_timestamp":"2025-06-02T08:15:14.870:+0000","tags":{},"timestamp":7766666666}