Resize and Autostart of Camera Stream with PyQt5/Qt5/OpenCV3/Raspberry Pi

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So i wanna have my camerastream automatically started and also would like to have a 1920x1080 or 1280x720 resolution. In the code the opencv frames get converted to qt images and i probably have to resize the qt image and not the opencv frames, so i dont know if the question fits in this sub but try to get all the help i can.

 #Importing necessary libraries, mainly the OpenCV, and PyQt libraries
import cv2
import numpy as np
import sys
from PyQt5 import QtCore
from PyQt5 import QtWidgets
from PyQt5 import QtGui
from PyQt5.QtCore import pyqtSignal

class ShowVideo(QtCore.QObject):

#initiating the built in camera
camera_port = 0
camera = cv2.VideoCapture(camera_port)
VideoSignal = QtCore.pyqtSignal(QtGui.QImage)


def __init__(self, parent = None):
    super(ShowVideo, self).__init__(parent)

@QtCore.pyqtSlot()
def startVideo(self):

    run_video = True
    while run_video:
        ret, image = self.camera.read()

        color_swapped_image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)

        height, width, _ = color_swapped_image.shape

        #width = camera.set(CAP_PROP_FRAME_WIDTH, 1600)
        #height = camera.set(CAP_PROP_FRAME_HEIGHT, 1080)
        #camera.set(CAP_PROP_FPS, 15)

        qt_image = QtGui.QImage(color_swapped_image.data,
                                width,
                                height,
                                color_swapped_image.strides[0],
                                QtGui.QImage.Format_RGB888)

        self.VideoSignal.emit(qt_image)
 
class ImageViewer(QtWidgets.QWidget):
    def __init__(self, parent = None):
        super(ImageViewer, self).__init__(parent)
        self.image = QtGui.QImage()
        self.setAttribute(QtCore.Qt.WA_OpaquePaintEvent)
 
def paintEvent(self, event):
    painter = QtGui.QPainter(self)
    painter.drawImage(0,0, self.image)
    self.image = QtGui.QImage()

def initUI(self):
    self.setWindowTitle('Test')

@QtCore.pyqtSlot(QtGui.QImage)
def setImage(self, image):
    if image.isNull():
        print("Viewer Dropped frame!")

    self.image = image
    if image.size() != self.size():
        self.setFixedSize(image.size())
    self.update()