NvTracke: tracker id don't change when object detect num change to 0

i use yolo+NvDCF to track object,i have two questions:
(1) set interval=4,when tack,the bounding box size change bigger;
(2)object id don’t change when detect object num changge to 0, only new object was detected.

(1) If interval=4, it means the one frame is to do detection to get bbox, the following 4 frames is to do tracking to get bbox. Does this “bigger” issue affect the result?
(2) Why you need to change numn to be 0 ?

(1) the bigger issue is solved, it’s caused by yolo v3 tiny;
(2)object appear and disappear in the camera view, the object id doesn’t change to -1;

i have try with IOU and KLT, the object id is right.

i want to track real-time, but NvDCF only work in the situation that object ID changed, when detected object disappear, the object id is not -1, and the id is still the result of last object.

(1)i set interval=0, the problem stilll exist.
(2)object num doesn’t change from 1 to 0, when object disappear int the cameara view.

i find that when the car has gone, the tracking bounding box still exist.
what can i do in this situation!

i have solve this problem by modify the config file in tracker_config.yml.