from threading import Thread
import threading
import sys
import cv2
import dlib

# 实测 多线程好那么一丢丢
def _help():
    print("Usage:")
    print("     python video_face_detect_dlib.py")
    print("     python video_face_detect_dlib.py <path of a video>")
    print("For example:")
    print("     python video_face_detect_dlib.py video/lee.mp4")
    print("If the path of a video is not provided, the camera will be used as the input.Press q to quit.")


def _face_detect(color_image, detector):
    gray_image = cv2.cvtColor(color_image, cv2.COLOR_BGR2GRAY)
    # img_row, img_col = gray_image.shape[:2]
    # scale = 0.3
    # gray_image = cv2.resize(gray_image, (int(scale * img_col), int(scale * img_row)))
    faces = detector(gray_image, 1)
    for face in faces:
        left = face.left()
        top = face.top()
        right = face.right()
        bottom = face.bottom()
        cv2.rectangle(color_image, (left, top), (right, bottom), (0, 255, 0), 2)
        cv2.namedWindow("Image", cv2.WINDOW_NORMAL)
        #cv2.imshow("Image", color_image)
    cv2.imshow("Image", color_image)


frame = None
lock = threading.RLock()


def get_frame(video_path):
    #video = "http://admin:admin@192.168.1.139:8081/"  # 此处@后的ipv4 地址需要改为app提供的地址
    cap = cv2.VideoCapture(video_path)
    global frame
    while True:
        _, img = cap.read()
        if img is None:
            break
        else:
            lock.acquire()
            frame = img
            lock.release()
    cap.release()


def face_detect(video_path="http://admin:admin@192.168.1.139:8081/"):
    detector = dlib.get_frontal_face_detector()
    # 开启后台线程不断获取视频输入流，并将视频帧保存到全局变量frame中
    t = Thread(target=get_frame, name="get_video_stream", args=(video_path,))
    t.daemon = True
    t.start()
    while True:
        if frame is not None:
            # 对最近保存在frame中的视频帧进行人脸检测
            lock.acquire()
            frame_copy = frame.copy()
            lock.release()
            _face_detect(frame_copy, detector)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    cv2.destroyAllWindows()


if len(sys.argv) > 2 or "-h" in sys.argv or "--help" in sys.argv:
    _help()
elif len(sys.argv) == 2:
    face_detect(sys.argv[1])
else:
    face_detect()