gully_drs_core/ball_detection.py

# gully_drs_core/ball_detection.py

import cv2
import numpy as np
from .model_utils import load_model

def find_bounce_point(path):
    """
    Finds the point where the ball bounces by detecting a Y-axis dip.
    """
    for i in range(1, len(path)-1):
        if path[i-1][1] > path[i][1] < path[i+1][1]:  # y dips = bounce
            return path[i]
    return None

def analyze_video(file_path):
    model = load_model()
    cap = cv2.VideoCapture(file_path)
    fps = cap.get(cv2.CAP_PROP_FPS)
    width  = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))

    ball_path = []
    frames = []

    while True:
        ret, frame = cap.read()
        if not ret:
            break

        results = model(frame)
        for r in results:
            for box in r.boxes:
                cls = int(box.cls[0])
                if cls == 32:  # cricket ball class
                    x1, y1, x2, y2 = map(int, box.xyxy[0])
                    cx, cy = (x1 + x2) // 2, (y1 + y2) // 2
                    ball_path.append((cx, cy))
                    cv2.circle(frame, (cx, cy), 6, (0, 255, 0), -1)

        frames.append(frame)

    cap.release()

    # Analyze trajectory
    bounce_point = find_bounce_point(ball_path)
    impact_point = ball_path[-1] if ball_path else None

    # Stump zone: middle area at bottom
    stump_zone = (
        width // 2 - 30,  # x1
        height - 100,     # y1
        width // 2 + 30,  # x2
        height            # y2
    )

    # LBW Decision: if impact is in stump zone
    decision = "OUT" if (
        impact_point and
        stump_zone[0] <= impact_point[0] <= stump_zone[2] and
        stump_zone[1] <= impact_point[1] <= stump_zone[3]
    ) else "NOT OUT"

    return {
        "trajectory": ball_path,
        "fps": fps,
        "frames": frames,
        "bounce_point": bounce_point,
        "impact_point": impact_point,
        "decision": decision,
        "stump_zone": stump_zone
    }