DxTracker

DxTracker is a GStreamer element designed to perform Multi-Object Tracking (MOT) on object detection results in a video stream. It uses bounding box metadata from upstream detection elements (such as DxPostprocess) to continuously track and assign consistent IDs across frames.

Currently, DxTracker supports the OC_SORT algorithm as its default tracking method. For more information about OC_SORT, refer to the Object Tracking Algorithms document.

Key Features

Multi-Object Tracking (MOT)
DxTracker tracks the movement of detected objects over time. It assigns unique track IDs to each object. Objects that can not be reliably tracked are discarded and not forwarded downstream.

Configurable Tracking Algorithms
Tracking algorithms and their parameters are defined in a JSON configuration file specified via the config-file-path property.

Example JSON configuration

{
    "tracker_name": "OC_SORT",
    "params": {
        "det_thresh": 0.5,
        "max_age": 30,
        "min_hits": 3,
        "iou_threshold": 0.3,
        "delta_t": 3,
        "asso_func": "iou",
        "inertia": 0.2,
        "use_byte": false
    }
}

The configuration file must include

• tracker_name: Specifies the tracking algorithm (e.g., OC_SORT)
• params: Contains algorithm-specific parameters

Default Behavior
If no config file is provided, DxTracker uses the OC_SORTalgorithm with built-in default values.
If only tracker_name is specified without params, the default parameter values for that algorithm are applied.

Limitations
The number of tracked objects is always less than or equal to the number of detected bounding boxes.
Algorithm parameters must be defined within the params block of the JSON file. These can not be set as individual GStreamer properties on the element.

Hierarchy

GObject
 +----GInitiallyUnowned
       +----GstObject
             +----GstElement
                   +----GstBaseTransform
                         +----GstDxTracker

Properties

Name	Description	Type	Default Value
name	Sets the unique name of the DxTracker element.	String	"dxtracker0"
config-file-path	Path to the JSON config file containing the tracking algorithm and parameters.	String	null
tracker-name	Specifies the name of the tracking algorithm to use.	String	"OC_SORT"

NOTE

• The JSON configuration file is required to customize tracking algorithm parameters.

• If no configuration file is provided, DxTracker uses OC_SORT with default settings.
• All parameters values must be defined within the params section of the JSON file.
• Track IDs are only assigned to successfully tracked objects. Objects that can not be tracked are removed and not passed downstream.

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