import cv2, sys, numpy as np

path = r"E:\test\Kiro_flash_detection\Video\0921 (1)_flash.mp4"
cap = cv2.VideoCapture(path)
if not cap.isOpened():
    print("FAILED to open"); sys.exit(1)

fps = cap.get(cv2.CAP_PROP_FPS)
n = cap.get(cv2.CAP_PROP_FRAME_COUNT)
w = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
h = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
dur = n / fps if fps else 0
print(f"fps={fps} frames={n} size={w}x{h} duration={dur:.2f}s ({dur/60:.2f} min)")

# The user says the flash is at 01:27:02 -> interpret as 1 min 27 sec (frame 02?)
# Extract a window around 87s.
for t in [86.5, 87.0, 87.08, 87.5, 88.0]:
    cap.set(cv2.CAP_PROP_POS_MSEC, t*1000)
    ok, frame = cap.read()
    if not ok:
        print(f"t={t}: read failed"); continue
    g = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    print(f"t={t:.2f}s frame~{int(t*fps)}: gray min={g.min()} max={g.max()} mean={g.mean():.1f} bright_px(>200)={int((g>200).sum())}")

cap.release()