Struct ByteTrack 

pub struct ByteTrack<T: DetectionBox> {
    pub track_extra_lifespan: u64,
    pub track_high_conf: f32,
    pub track_iou: f32,
    pub track_update: f32,
    pub tracklets: Vec<Tracklet<T>>,
    pub frame_count: i32,
}

ByteTrack multi-object tracker — the concrete Tracker implementation.

Prefer constructing via ByteTrackBuilder rather than directly, since the public fields default to zero-values that are not usable defaults.

Algorithm overview

Each call to Tracker::update runs a two-pass IoU matching loop:

1. Predict. Every active tracklet’s Kalman filter advances one step, predicting where the object should appear this frame.
2. High-confidence pass. Detections scoring ≥ track_high_conf are assigned to existing tracklets via LAPJV linear assignment on an IoU cost matrix (cells below track_iou are set to INVALID_MATCH).
3. Low-confidence pass. Remaining unmatched tracklets are tried against all remaining detections (any score) — this recovers briefly occluded objects without admitting low-quality detections into the high-confidence pool.
4. Expire. Tracklets whose last_updated is more than track_extra_lifespan nanoseconds behind timestamp are removed.
5. Spawn. Unmatched high-confidence detections spawn new tracklets.

Thread safety

ByteTrack<T> is Send + Sync (provided T: Send + Sync). Mutable methods take &mut self; callers that share a tracker across threads must serialize with an external mutex.

Fields

track_extra_lifespan: u64

How long (in nanoseconds) a tracklet may go unmatched before it is deleted. Default: 500 ms (500_000_000 ns).

track_high_conf: f32

Minimum detection score to enter the high-confidence matching pass and to spawn new tracklets. Default: 0.7.

track_iou: f32

Minimum IoU required for a detection–tracklet assignment to be accepted. Pairs below this threshold are set to INVALID_MATCH in the cost matrix. Default: 0.25.

track_update: f32

Kalman filter measurement gain (0–1). Lower values trust the Kalman prediction more; higher values follow the raw detection more closely. Default: 0.25.

tracklets: Vec<Tracklet<T>>

All currently active tracklets (matched or unmatched-but-not-expired).

frame_count: i32

Running count of frames processed since the tracker was created. Incremented on every Tracker::update call, including empty frames.

Trait Implementations

impl<T: Clone + DetectionBox> Clone for ByteTrack<T>

fn clone(&self) -> ByteTrack<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug + DetectionBox> Debug for ByteTrack<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Default + DetectionBox> Default for ByteTrack<T>

fn default() -> ByteTrack<T>

Returns the “default value” for a type.

impl<T> Tracker<T> for ByteTrack<T>

where T: DetectionBox,

fn update(&mut self, boxes: &[T], timestamp: u64) -> Vec<Option<TrackInfo>>

Process one frame of detections and advance all internal tracklet states.

fn get_active_tracks(&self) -> Vec<ActiveTrackInfo<T>>

Return all currently active tracklets, including those not matched in the most recent frame but not yet expired.