how to save video in YOLO

Question

I am trying to save the video after detection in yolo, it saves the video but don't show detected items. Code is here

import cv2
from darkflow.net.build import TFNet
import numpy as np
import time
import os
from PyQt5 import QtCore, QtWidgets, QtGui, uic
from PyQt5.QtWidgets import QPushButton, QInputDialog, QLineEdit
from PyQt5.uic import loadUi
import sys
from PIL import Image

option= {
    'model':'cfg/yolo.cfg',
    'load':'bin/yolov2.weights',
    'threshold': 0.3,
    }
class MyWindow(QtWidgets.QMainWindow):

    def __init__(self):
        super(MyWindow, self).__init__()
        loadUi("new.ui", self)
        self.testcam.clicked.connect(self.CameraTest)
        self.start.clicked.connect(self.Camera)
        

    def CameraTest(self):
        cap = cv2.VideoCapture(0)
        cap.set(3,640) # set Width
        cap.set(4,480) # set Height
        while(True):
            ret, frame = cap.read()
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    
            cv2.imshow('CamTest', frame)
    
            k = cv2.waitKey(30) & 0xff
            if k == 27: # press 'ESC' to quit
                break
        cap.release()
        cv2.destroyAllWindows()
    def Camera(self):

        tfnet = TFNet(option)
        colors = [tuple(255 * np.random.rand(3)) for _ in range(10)]

        cap= cv2.VideoCapture(0)
        #cap.set(cv2.CAP_PROP_FRAME_WIDTH, 512)
        #cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 512)
        fourcc=cv2.VideoWriter_fourcc(*'XVID')
        out=cv2.VideoWriter('new.avi',fourcc,20.0,(640,480))

        while True:
            stime = time.time()
            ret, frame = cap.read()
            out.write(frame)
            if (ret==True):
                
                results = tfnet.return_predict(frame)
                for color, result in zip(colors, results):
                    tl = (result['topleft']['x'], result['topleft']['y'])
                    br = (result['bottomright']['x'], result['bottomright']['y'])
                    label = result['label']
                    confidence = result['confidence']
                    text = '{}: {:.0f}%'.format(label, confidence * 100)
                    frame = cv2.rectangle(frame, tl, br, color, 5)
                    frame = cv2.putText(
                        frame, text, tl, cv2.FONT_HERSHEY_COMPLEX, 1, (0, 0, 0), 2)
                cv2.imshow('frame', frame)
                print('FPS {:.1f}'.format(1 / (time.time() - stime)))
                if cv2.waitKey(1) & 0xFF == ord('q'):
                    break
            else:
                break

        cap.release()
        out.release()
        cv2.destroyAllWindows()
if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    window = MyWindow()
    window.show()
    sys.exit(app.exec_())

Answer 1

these two lines should be written before the loop

codec = cv2.VideoWriter_fourcc(*"MJPG")

out = cv2.VideoWriter('./processed.avi' , codec, fps, (width, height))

this should be inside the loop just above imshow()

out.write(frame)