# bytetrack-counter-go

Edge-computing live video analytics counter for industrial poultry processing. Connects to an RTSP camera, runs YOLO object detection on a Rockchip RKNN NPU, tracks objects with ByteTrack, and counts chickens ("ayam") crossing a virtual line. Closes counting batches when a cutting board ("talenan") crosses the line. Persists batch data to SQLite.

## Architecture

```
RTSP Camera --> gocv.VideoCapture --> YOLO (RKNN NPU) --> ByteTrack
                                                              |
                                                     Line-Crossing Logic
                                                              |
                                              +-----> BatchStore (SQLite)
                                              |
                                         HUD Drawing --> Video Output / Live JPEG
```

## Requirements

- **Rockchip RK3588** (or compatible) with RKNN NPU
- **librknnrt** (Rockchip RKNN Runtime library, `>=1.6.0`)
- **OpenCV 4.x** with GoCV bindings
- **Go 1.23+**
- **CGo enabled** (required for RKNN and GoCV)

### Installing GoCV / OpenCV

On RK3588 (Armbian/Ubuntu):

```bash
sudo apt install -y libopencv-dev pkg-config
go get -u gocv.io/x/gocv
```

### Installing librknnrt

```bash
# Copy librknnrt.so to the device (obtained from Rockchip SDK)
sudo cp librknnrt.so /usr/lib/aarch64-linux-gnu/
sudo ldconfig
```

Verify:

```bash
ls /usr/lib/aarch64-linux-gnu/librknnrt.so
# Should also have: librknn_rk3588.so or similar NPU driver
```

## Compiling

Clone and build:

```bash
git clone https://git.proit.id/dsutanto/bytetrack-counter-go.git
cd bytetrack-counter-go
CGO_ENABLED=1 go build -o counter ./cmd/counter/
```

The `-o counter` flag places the binary at `./counter`. For production, copy it to `/opt/bytetrack-counter-go/counter`.

To verify the binary links correctly:

```bash
ldd ./counter | grep rknn
# Should show librknnrt.so => /usr/lib/aarch64-linux-gnu/librknnrt.so
```

### Cross-compiling from amd64

```bash
CGO_ENABLED=1 GOOS=linux GOARCH=arm64 \
  CGO_LDFLAGS="-L/path/to/rknn-libs -lrknnrt" \
  go build -o counter ./cmd/counter/
```

## Configuration

All configuration is via environment variables. Copy the example and edit:

```bash
cp config.env.example .env
nano .env
```

Key settings:

| Variable | Default | Description |
|----------|---------|-------------|
| `SOURCE` | — | RTSP URL or video file path (required) |
| `MODEL_PATH` | — | Path to `.rknn` YOLO model (required) |
| `OUTPUT_DIR` | `/opt/jetson-counter` | Output directory for DB, state, CSV, video |
| `IMGSZ` | `320` | YOLO input image size (must match model) |
| `CONF` | `0.3` | Detection confidence threshold |
| `CORE_MASK` | `1` | RKNN NPU cores: 1=core0, 2=core1, 3=both, 7=all three |
| `NUM_CLASSES` | `2` | Number of YOLO classes |
| `CLASS_AYAM` | `ayam` | Object class to count |
| `CLASS_TALENAN` | `talenan` | Object class to close batches |
| `LINE_X_FRAC` | `0.5` | Counting line X position (fraction of frame width) |
| `CROSS_DIRECTION` | `rtl` | Crossing direction: `rtl`, `ltr`, or `both` |
| `DAILY_CUTOFF_TIME` | `20:00` | Time to roll over to next counting day |
| `BATCH_TIMEOUT_SECONDS` | `300` | Inactivity timeout to close a batch |
| `MIN_OBJECT_PER_BATCH` | `60` | Minimum chickens per batch |
| `OPENCV_FFMPEG_CAPTURE_OPTIONS` | — | FFmpeg options for low-latency RTSP |

See `config.env.example` for the full list.

## Running

### Interactive (foreground)

```bash
set -a && source .env && set +a
./counter
```

### systemd (production)

```bash
# Install binary and config
sudo mkdir -p /opt/bytetrack-counter-go
sudo cp counter /opt/bytetrack-counter-go/
sudo cp .env /opt/bytetrack-counter-go/
sudo cp config.env.example /opt/bytetrack-counter-go/

# Install and start service
sudo cp bytetrack-counter-go.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable bytetrack-counter-go
sudo systemctl start bytetrack-counter-go

# Monitor
sudo journalctl -u bytetrack-counter-go -f
```

## Directory Structure

```
.
├── cmd/counter/main.go          # Application entrypoint
├── pkg/
│   ├── batchstore/store.go      # SQLite batch persistence + JSON state
│   ├── bytetrack/tracker.go     # ByteTrack multi-object tracker
│   ├── config/config.go         # Env-based configuration loader
│   ├── drawing/drawing.go       # OpenCV HUD drawing helpers
│   ├── kalman/kalman.go         # 8-state Kalman filter
│   ├── rknn/rknn.go             # CGo bridge to librknnrt
│   └── yolo/yolo.go             # YOLO detector (RKNN inference + NMS)
├── internal/
│   ├── iou/iou.go               # IoU computation + greedy matching
│   └── nms/nms.go               # Non-maximum suppression
├── config.env.example           # Example configuration
├── bytetrack-counter-go.service # systemd unit file
├── go.mod
└── go.sum
```