videostream.py

from pyzbar.pyzbar import decode
from threading import Thread

from config import settings

import cv2
import time
import numpy as np

class VideoStream:
    def __init__(self):
        print("init")
        # self.stream = cv2.VideoCapture(settings.RTMP_ADDRESS)
        self.stream = cv2.VideoCapture(1)
        
        fps = self.stream.get(cv2.CAP_PROP_FPS)
        if fps == 0:
            fps = 30.0
        self.frame_duration = 1.0 / fps
        
        (self.grabbed, self.frame) = self.stream.read()
        self.stopped = False
        
        self.qrcodes = []
        time.sleep(2.0)
    
    def start(self):
        print("start thread")
        t = Thread(target=self.update, args=())
        t.daemon = True
        t.start()
        return self
    
    def update(self):
        print("read")
        sync_counter = 0
        sync_start_time = time.time()
        ignore_sleep = False

        while True:
            if self.stopped:
                return
            
            start_time = time.time()
            (self.grabbed, self.frame) = self.stream.read()

            if not ignore_sleep:
                sleep_time = max(0, self.frame_duration - (time.time() - start_time))
                time.sleep(sleep_time)

            if time.time() - sync_start_time >= 10:
                sync_counter += 5
                ignore_sleep = True

                if sync_counter >= 100:
                    sync_counter = 0
                    sync_start_time = time.time()
                    ignore_sleep = False
            
    def read(self):
        return self.frame
    
    def read_qr(self):
        qr_codes = decode(self.frame)
        frame_qr_code_data = []
        
        for qr_code in qr_codes:
            (x, y, w, h) = qr_code.rect
            cv2.rectangle(self.frame, (x, y), (x + w, y + h), (0, 255, 0), 2)
            qr_data = qr_code.data.decode('utf-8')
            cv2.putText(self.frame, qr_data, (x, y - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 0, 0), 2)
            
            frame_qr_code_data.append(qr_data)
                
        if len(frame_qr_code_data) >= 2:
            self.qrcodes = frame_qr_code_data
        
        return (self.frame, frame_qr_code_data)

    
    def stop(self):
        self.stopped = True