基于flask与opencv制作一个视频监控小程序

基于flask与opencv制作一个视频监控小程序：

主要实现引入视频流到web页面

import cv2
import numpy as np
from flask import Flask, render_template, Response

app = Flask(__name__)
video_writer = None

class Camera:
    _instance = None
    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
            cls._instance.camera = cv2.VideoCapture(0)
        return cls._instance

    def __del__(self):
        self.camera.release()

    def get_frame(self):
        success, frame = self.camera.read()
        if not success:
            return None
        else:
            ret, buffer = cv2.imencode('.jpg', frame)
            frame = buffer.tobytes()
            return frame

camera = Camera()


def convert_bytes_to_frame(frame_bytes):
    # 将bytes类型的图像数据解码为OpenCV图像格式
    frame_array = np.frombuffer(frame_bytes, dtype=np.uint8)
    frame = cv2.imdecode(frame_array, flags=cv2.IMREAD_COLOR)
    return frame

# 获取视频流
def get_video_stream():
    global camera,video_writer
    while True:
        if camera is None:
            break
        frame = camera.get_frame()
        if frame is None:
            break
        else:
            if video_writer is not None:
                video_writer.write(convert_bytes_to_frame(frame))
            yield (b'--frame\r\n'
                   b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')

# 关闭摄像头
def close_camera():
    global camera
    camera = None

@app.route('/open_camera', methods=['POST'])
def open_camera_route():
    global camera
    camera = Camera()
    return Response(get_video_stream(), mimetype='multipart/x-mixed-replace; boundary=frame')

@app.route('/close_camera', methods=['POST'])
def close_camera_route():
    close_camera()
    return 'Camera closed'

@app.route('/')
def index():
    return render_template('index3.html')

@app.route('/video_feed')
def video_feed():
    return Response(get_video_stream(), mimetype='multipart/x-mixed-replace; boundary=frame')

@app.route('/start_recording')
def start_recording():
    global video_writer
    video_writer = cv2.VideoWriter('output.avi', cv2.VideoWriter_fourcc(*'XVID'), 20.0, (640, 480))
    return 'Recording started'

@app.route('/stop_recording')
def stop_recording():
    global video_writer
    video_writer.release()
    video_writer = None
    return 'Recording stopped'

if __name__ == '__main__':
    app.run(debug=True)

前台页面写法

    

  

    
监控视频流
    
    

    打开摄像头
    关闭摄像头
    

    开始录像
    结束录像