utils.py

import cv2
import torch
import numpy as np
from torchvision import transforms

def extract_frames(video_path, num_frames=71, resize=(224, 224)):
    cap = cv2.VideoCapture(video_path)
    total = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
    interval = max(total // num_frames, 1)

    frames = []
    for i in range(num_frames):
        cap.set(cv2.CAP_PROP_POS_FRAMES, i * interval)
        ret, frame = cap.read()
        if not ret:
            break
        frame = cv2.resize(frame, resize)
        frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
        frames.append(frame / 255.0)
    cap.release()
    
    frames = np.stack(frames, axis=0)
    frames = torch.tensor(frames, dtype=torch.float32).permute(0, 3, 1, 2)  # (T, C, H, W)
    return frames.unsqueeze(0)  # (1, T, C, H, W)