#!/usr/bin/env python3
"""Minimal example: iterate over recordings, read frames, and (if present) load the belt reference.

    python load_example.py --root <download_dir> --domain outdoor --max-frames 300
"""
import argparse
import cv2
import pandas as pd

ap = argparse.ArgumentParser()
ap.add_argument("--root", required=True)
ap.add_argument("--domain", choices=["indoor", "outdoor"], default="outdoor")
ap.add_argument("--max-frames", type=int, default=300)
a = ap.parse_args()

meta = pd.read_csv(f"{a.root}/metadata.csv")
meta = meta[meta.domain == a.domain]
for _, r in meta.iterrows():
    cap = cv2.VideoCapture(f"{a.root}/{r.file_name}")
    if not cap.isOpened():
        print("not downloaded:", r.file_name)
        continue
    n = 0
    while n < a.max_frames:
        ok, frame = cap.read()
        if not ok:
            break
        n += 1          # frame is a BGR uint8 array, shape (H, W, 3)
    print(f"{r.file_name:38s} {int(r.width)}x{int(r.height)} @ {r.fps:g} fps, {r.duration_s:.0f} s, read {n} frames")
    cap.release()