bytetrack-counter-cpp/AGENTS.md

AGENTS.md — ByteTrack Counter C++

RKNN Dynamic Shape Requirement

The RKNN model (zenai_apc_cicalengka_20260609.rknn) is exported with dynamic input shapes (model inference type: dynamic_shape). The C API requires calling rknn_set_input_shapes() before rknn_inputs_set(). Without it, librknnrt.so crashes with:

std::out_of_range: vector::_M_range_check: __n (which is 18446744073709551615) >= this->size() (which is 1)

This is called in the constructor of RKNNYOLO at src/rknn_yolo.cpp:60, right after querying input attributes:

in_attr.dims[0] = 1;
in_attr.dims[1] = imgsz_;
in_attr.dims[2] = imgsz_;
in_attr.dims[3] = 3;
in_attr.n_dims = 4;
ret = rknn_set_input_shapes(rknn_ctx_, io_num.n_input, &in_attr);

Build

cd /opt/bytetrack-counter-cpp/build
cmake .. -DHAS_RKNN=ON
make -j$(nproc)

Service

systemctl restart bytetrack-counter
journalctl -u bytetrack-counter -f

Reset via .reset file

Place a .reset file in SHM_DIR (default /dev/shm/bytetrack-counter) to trigger a full state reset:

• Startup: deleting .reset before service starts clears all state files on boot
• Runtime: dropping .reset while service runs calls BatchStore::reset() — ends active batch, clears in-memory state, deletes STATE_FILE, clears live stream JPEG + writes blank frame on next write

touch /dev/shm/bytetrack-counter/.reset

Shared memory

SHM_DIR (/dev/shm/bytetrack-counter by default) stores:

• LIVE_STREAM_FRAME_PATH JPEG snapshot
• RECORD_SHM_DIR video recordings before move to disk
• .reset trigger file

Directory auto-created at startup.