Where does nvtracker get its metadata from?

Accelerated Computing Intelligent Video Analytics DeepStream SDK
1

Hello! I am new to GStreamer, and am attempting to write a pipeline that includes nvinfer and nvtracker.

I also wrote a plugin that prints out the bounding box metadata in the stream for each buffer, placing one after nvinfer and another after nvtracker, as follows:
nvinfer → printmeta → nvtracker → printmeta

However, for a particular frame, it seems that nvtracker detects more boxes than nvinfer. Simple example below:

<PrintMeta After Infer, Frame Num 12>
10 boxes found.
<PrintMeta After Tracker, Frame Num 12>
13 boxes found.

Furthermore, since I set nvinfer at interval 10, in frames where nvinfer does not run, the following scenario occurs:
<PrintMeta After Infer, Frame Num 11>
0 boxes found.
<PrintMeta After Tracker, Frame Num 11>
10 boxes found.

Thus, my question is why is this so? Does nvtracker also obtain bounding box information from other sources?

Thank you for your time!

Best Regards,
Johnson

2

Hi,

Tracker is applied across different frames.
It may contain the bounding boxes detected in the previous frames.

Thanks.