def crop(imgs):
    """
    Centre crops frames to be divisible by 64
    Args:
        imgs: list of images
    Returns: the list of images now cropped
    """
    if len(imgs) < 1:
        return imgs
    h, w, _ = imgs[0].shape
    if h % 64 or w % 64:  # not evenly divided by 64
        th = (h//64) * 64
        tw = (w//64) * 64
        for i in range(len(imgs)):  # crop each frame
            imgs[i] = imgs[i][(h - th) // 2:(h + th) // 2, (w - tw) // 2:(w + tw) // 2, :]
    return imgs