Read barcode with QT5 camera without cv

process_camera.py

#!/usr/bin/env python

import io
import sys
import beepy

from PIL import Image
from PyQt5 import QtCore, QtMultimedia, QtGui
from PyQt5.QtMultimedia import *
from PyQt5.QtMultimediaWidgets import *
from PyQt5.QtWidgets import *
from pyzbar import pyzbar


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        self.available_cameras = QCameraInfo.availableCameras()
        if not self.available_cameras:
            print("No camera found.")
            sys.exit()
        self.known_codes = set()

        self.camera = QCamera(self.available_cameras[0])
        self.camera.setCaptureMode(QCamera.CaptureViewfinder)
        self.camera.imageProcessing().setWhiteBalanceMode(QCameraImageProcessing.WhiteBalanceAuto)
        
        self.current_camera_name = self.available_cameras[0].description()
        self.capture = QCameraImageCapture(self.camera)
        self.capture.setCaptureDestination(QCameraImageCapture.CaptureToBuffer)
        self.probe = QtMultimedia.QVideoProbe(self)
        self.probe.videoFrameProbed.connect(self.processFrame)
        self.probe.setSource(self.camera)
        
        exposure = self.camera.exposure()
        exposure.setExposureMode(QCameraExposure.ExposureAuto)
        exposure.setExposureCompensation(0)
        exposure.setMeteringMode(QCameraExposure.MeteringSpot)

        self.status = QStatusBar()
        self.setStatusBar(self.status)
        self.status.showMessage(f"Using {self.current_camera_name}")
        self.viewfinder = QCameraViewfinder()
        self.viewfinder.show()
        self.setCentralWidget(self.viewfinder)
        self.camera.setViewfinder(self.viewfinder)
        toolbar = QToolBar()
        self.addToolBar(toolbar)
        start_action = QAction(
            self.style().standardIcon(QStyle.SP_MediaPlay), "Start camera", self
        )
        start_action.triggered.connect(self.startCamera)
        toolbar.addAction(start_action)
        stop_action = QAction(
            self.style().standardIcon(QStyle.SP_MediaStop), "Stop camera", self
        )
        stop_action.triggered.connect(self.stopCamera)
        toolbar.addAction(stop_action)
        self.setGeometry(100, 100, 800, 600)
        self.show()

    def startCamera(self):
        self.camera.start()

    def stopCamera(self):
        self.camera.stop()

    def processFrame(self, frame):
        QApplication.processEvents()
        if frame.isValid():
            cloneFrame = QVideoFrame(frame)
            cloneFrame.map(QAbstractVideoBuffer.MapMode.ReadOnly)
            buffer = QtCore.QBuffer()
            buffer.open(QtCore.QBuffer.ReadWrite)
            frame.image().save(buffer, "JPEG")
            pil_im = Image.open(io.BytesIO(buffer.data()))
            barcodes = pyzbar.decode(pil_im)
            for barcode in barcodes:
                data = barcode.data.decode("utf-8")
                if data not in self.known_codes:
                    self.known_codes.add(data)
                    message = f"Found Type : {barcode.type} Barcode : {data}"
                    self.status.showMessage(message)
                    print(message)
                    beepy.beep()
            cloneFrame.unmap()

    def closeEvent(self, event):
        if self.probe.isActive():
            self.probe.videoFrameProbed.disconnect(self.processFrame)
            self.probe.deleteLater()
        self.camera.stop()
        event.accept()

if __name__ == "__main__":
    app = QApplication(sys.argv)
    app.setStyle(QStyleFactory.create("fusion"))
    mainWindow = MainWindow()
    mainWindow.show()
    sys.exit(app.exec_())