pyqt5 qlabel显示实时视频流报错 Segmentation fault (core dumped) 解决办法

1. 报错

用qlabel显示实时视频流，但是有时候会突然中止，可能的原因有两点：

• qlabel的size与图片size不一致，可能导致无法显示图片或者报错
• qlabel刷新速度过快，比如实时视频流的拉取速度没有处理速度快，也可能报错

2. 代码实现

# coding=gbk //放到文件首行

import sys,math
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import numpy as np 
import cv2
import os 
import time 
import base64
import copy
from PIL import Image, ImageDraw, ImageFont
from queue import LifoQueue
import threading 

Decode2Play = LifoQueue()
#lock = threading.Lock()

class cvDecode(QThread):
    def __init__(self):
        super(cvDecode, self).__init__()
        self.threadFlag = 0     #   控制线程退出
        self.rtsp = "rtsp://用户名:密码@摄像头ip"
        self.cap = cv2.VideoCapture(self.rtsp)    

    def run(self):
        #print("当前线程cvDecode: self.threadFlag:{}".format(self.threadFlag))
        while self.threadFlag:
            if self.cap.isOpened():
                ret, frame = self.cap.read()
                time.sleep(0.001)   # 控制读取录像的时间，连实时视频的时候改成time.sleep(0.001)，多线程的情况下最好加上，否则不同线程间容易抢占资源

                if ret:
                    #lock.acquire()
                    Decode2Play.put(frame)  # 解码后的数据放到队列中
                    #lock.release()

                del frame  # 释放资源

class play_Work(QThread):
    def __init__(self):
        super(play_Work, self).__init__()
        self.threadFlag = 0         #   控制线程退出
        self.playLabel = QLabel()   #   初始化QLabel对象
        ################ 修改部分1 ################
        self.new_width, self.new_height = self.playLabel.size().width(), self.playLabel.size().height() 
        
        #cv2.namedWindow("test")
        #cv2.resizeWindow("test", 640, 480)

    def run(self):
        while self.threadFlag:       
            if not Decode2Play.empty():
                frame = Decode2Play.get()
                while not Decode2Play.empty():
                    Decode2Play.get()      
                
                ################ 修改部分2 ################
                #frame = cv2.resize(frame, (800, 600), cv2.INTER_LINEAR)
                frame = cv2.resize(frame, (self.new_height, self.new_width), cv2.INTER_LINEAR))
                frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
                qimg = QImage(frame.data, frame.shape[1], frame.shape[0], QImage.Format_RGB888)  # 在这里可以对每帧图像进行处理，
                self.playLabel.setPixmap(QPixmap.fromImage(qimg))   #   图像在QLabel上展示
                #cv2.imshow('test', frame)
                    
            ################ 修改部分3 ################
            #time.sleep(0.001)
            time.sleep(0.1)


class MyWindow(QWidget):
    #opencam_complete_signal = pyqtSignal(str)  # 子线程返回摄像头图像到主线程的信号
    def __init__(self):
        super().__init__()
        self.setGeometry (0, 0, 840, 800) 
        #self.setFixedSize(1600, 960)
        
        self.init_ui()
 
    def init_ui(self):
        self.cam_view = QLabel(self)
        self.cam_view.setStyleSheet("border:2px solid black")
        self.cam_view.setGeometry(20, 20, 800, 600)
        
        self.open_cam_btn = QPushButton(self)
        #self.pushButton.setStyleSheet("border:2px solid black")
        self.open_cam_btn.setText('播放')
        self.open_cam_btn.setGeometry(380, 700, 100, 30)
        self.open_cam_btn.clicked.connect(self.init_work)
        
    def init_work(self):
        self.decodework = cvDecode()
        self.decodework.threadFlag = 1
        self.decodework.start()

        self.playwork = play_Work()
        self.playwork.threadFlag = 1
        self.playwork.playLabel = self.cam_view
        self.playwork.start()
 
    def closeEvent(self, event):
        print("关闭线程")
        # Qt需要先退出循环才能关闭线程
        if self.decodework.isRunning():
            self.decodework.threadFlag = 0
            self.decodework.quit()
        if self.playwork.isRunning():
            self.playwork.threadFlag = 0
            self.playwork.quit()


if __name__ == '__main__':
    app = QApplication(sys.argv)  # 创建对象
 
    w = MyWindow()
    # 展示窗口
    w.show()
 
    # 程序进行循环等待状态
    app.exec_()