PYQT 读取摄像头显示视频（Qtimer的方式 ）

建立界面

使用qtdesigner设计一个基本的播放视频界面

使用PYUIC生成对应代码文件，如下：

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'Test_UI.ui'
#
# Created by: PyQt5 UI code generator 5.15.9
#
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again.  Do not edit this file unless you know what you are doing.


from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(883, 637)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.pushButton_start = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_start.setGeometry(QtCore.QRect(160, 480, 141, 51))
        self.pushButton_start.setObjectName("pushButton_start")
        self.label_show = QtWidgets.QLabel(self.centralwidget)
        self.label_show.setGeometry(QtCore.QRect(150, 60, 541, 371))
        self.label_show.setStyleSheet("background-color: rgb(0, 0, 0);")
        self.label_show.setText("")
        self.label_show.setObjectName("label_show")
        self.pushButton_end = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_end.setGeometry(QtCore.QRect(550, 480, 141, 51))
        self.pushButton_end.setObjectName("pushButton_end")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 883, 22))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.pushButton_start.setText(_translate("MainWindow", "开始"))
        self.pushButton_end.setText(_translate("MainWindow", "结束"))

主函数

核心需要实现的功能就是按下按钮打开摄像头进行读取，然后关闭摄像头

通过QTimer实现

这样可以比较简单的实现，就是timer计时到了就新读取一帧

from PyQt5 import QtWidgets,QtCore
from PyQt5.QtWidgets import QMainWindow,QApplication
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import sys
import cv2

import Test_UI

import threading


# 注意：ui界面文件是个MainWindow，那么MyApp就必须继承 QMainWindow
# 类似的，若ui界面文件是个对话框，那么MyApp就必须继承 QDialog
class Test_window(QtWidgets.QMainWindow,Test_UI.Ui_MainWindow):
    def __init__(self,parent=None):
        super(Test_window,self).__init__(parent)
        self.setupUi(self)
        self.CAM_NUM = 0
        self.cap = cv2.VideoCapture()

        self.timer = QTimer()
        self.timer.timeout.connect(self.show_pic)

        # 文件选择按钮
        self.pushButton_start.clicked.connect(self.open_camera)
        self.pushButton_end.clicked.connect(self.close_camera)

        self.pushButton_start.setEnabled(True)
        # 初始状态不能关闭摄像头
        self.pushButton_end.setEnabled(False)

    def open_camera(self):
        # 检测该设备是否能打开
        flag = self.cap.open(self.CAM_NUM)
        print(flag)
        if flag is False:
            QMessageBox.information(self, "警告", "该设备未正常连接", QMessageBox.Ok)
        else:
            # 幕布可以播放
            self.label_show.setEnabled(True)
            # 打开摄像头按钮不能点击
            self.pushButton_start.setEnabled(False)
            # 关闭摄像头按钮可以点击
            self.pushButton_end.setEnabled(True)
            self.timer.start()
            print("beginning！")

    # 关闭相机
    def close_camera(self):
        self.cap.release()
        self.pushButton_start.setEnabled(True)
        self.pushButton_end.setEnabled(False)
        self.timer.stop()

    #   显示视频图像
    def show_pic(self):
        ret, img = self.cap.read()
        if ret:
            cur_frame = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
            # 视频流的长和宽
            height, width = cur_frame.shape[:2]
            pixmap = QImage(cur_frame.data, width, height, QImage.Format_RGB888)
            pixmap = QPixmap.fromImage(pixmap)
            # # 获取是视频流和label窗口的长宽比值的最大值，适应label窗口播放，不然显示不全
            # ratio = max(width / self.label.width(), height / self.label.height())
            # pixmap.setDevicePixelRatio(ratio)
            # print("here")
            # # 视频流置于label中间部分播放
            # self.label_show.setAlignment(Qt.AlignCenter)
            self.label_show.setPixmap(pixmap)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    mytest = Test_window()
    mytest.show()
    app.exec_()

加上对于图像的处理

比如我这里加上对于姿态识别，好像不用到多线程也行，就直接在图片显示函数里，进行图片的推理就行了，没什么太大的影响。

from PyQt5 import QtWidgets,QtCore
from PyQt5.QtWidgets import QMainWindow,QApplication
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import sys
import cv2

import Test_UI

import threading

import Gesture_Model


# 注意：ui界面文件是个MainWindow，那么MyApp就必须继承 QMainWindow
# 类似的，若ui界面文件是个对话框，那么MyApp就必须继承 QDialog
class Test_window(QtWidgets.QMainWindow,Test_UI.Ui_MainWindow):
    def __init__(self,parent=None):
        super(Test_window,self).__init__(parent)
        self.setupUi(self)
        self.CAM_NUM = 0
        self.cap = cv2.VideoCapture()

        self.geture_model = Gesture_Model.Gesture()

        self.timer = QTimer()
        self.timer.timeout.connect(self.show_pic)

        # 文件选择按钮
        self.pushButton_start.clicked.connect(self.open_camera)
        self.pushButton_end.clicked.connect(self.close_camera)

        self.pushButton_start.setEnabled(True)
        # 初始状态不能关闭摄像头
        self.pushButton_end.setEnabled(False)

    def open_camera(self):
        # 检测该设备是否能打开
        # flag = self.cap.open(self.CAM_NUM)
        flag = self.cap.open('./test/002.mp4')
        print(flag)
        if flag is False:
            QMessageBox.information(self, "警告", "该设备未正常连接", QMessageBox.Ok)
        else:
            # 幕布可以播放
            self.label_show.setEnabled(True)
            # 打开摄像头按钮不能点击
            self.pushButton_start.setEnabled(False)
            # 关闭摄像头按钮可以点击
            self.pushButton_end.setEnabled(True)
            self.timer.start()
            print("beginning！")

    # 关闭相机
    def close_camera(self):
        self.cap.release()
        self.pushButton_start.setEnabled(True)
        self.pushButton_end.setEnabled(False)
        self.timer.stop()

    #   显示视频图像
    def show_pic(self):
        ret, img = self.cap.read()
        if ret:
            cur_frame = self.geture_model.pred(img)
            cur_frame = cv2.cvtColor(cur_frame, cv2.COLOR_BGR2RGB)
            # 视频流的长和宽
            height, width = cur_frame.shape[:2]
            pixmap = QImage(cur_frame.data, width, height, QImage.Format_RGB888)
            pixmap = QPixmap.fromImage(pixmap).scaled(self.label_show.width(), self.label_show.height())
            self.label_show.setPixmap(pixmap)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    mytest = Test_window()
    mytest.show()
    app.exec_()