python-3.x - 如何使用 OpenCV 和 QThread 在 pyqt5 gui 中录制来自网络摄像头的视频?
问题描述
我正在尝试制作 pyqt5 Gui 来显示网络摄像头实时提要,同时记录提要,并在关闭时将其保存在本地。我设法在pyqt gui中使用Timer(QTimer)实现了这一点,但是当我尝试使用Qthread(我真的需要)实现它时,只有实时提要正在工作。
每当我添加录制视频所需的代码并运行程序时,它都会显示Python 已停止工作并关闭。这是我的代码:
import cv2
import sys
from PyQt5.QtWidgets import QWidget, QLabel, QApplication, QVBoxLayout
from PyQt5.QtCore import QThread, Qt, pyqtSignal, pyqtSlot
from PyQt5.QtGui import QImage, QPixmap
class Thread(QThread):
changePixmap = pyqtSignal(QImage)
def run(self):
self.cap = cv2.VideoCapture(0)
self.width = int(self.cap.get(cv2.CAP_PROP_FRAME_WIDTH))
self.height = int(self.cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
self.codec = cv2.VideoWriter_fourcc('X', 'V', 'I', 'D')
self.writer = cv2.VideoWriter('output.avi', self.codec, 30.0, (self.width, self.height))
while self.cap.isOpened():
ret, self.frame = self.cap.read()
if ret:
self.frame = cv2.flip(self.frame, 1)
rgbimage = cv2.cvtColor(self.frame, cv2.COLOR_BGR2RGB)
h, w, ch = rgbimage.shape
bytesPerLine = ch * w
convertToQtFormat = QImage(rgbimage.data, w, h, bytesPerLine, QImage.Format_RGB888)
p = convertToQtFormat.scaled(640, 480, Qt.KeepAspectRatio)
self.changePixmap.emit(p)
class MyApp(QWidget):
def __init__(self):
super(MyApp, self).__init__()
self.title = 'Camera'
self.initUI()
def initUI(self):
self.label = QLabel(self)
lay = QVBoxLayout()
lay.addWidget(self.label)
self.setLayout(lay)
self.th = Thread()
self.th.changePixmap.connect(self.setImage)
self.th.start()
self.show()
@pyqtSlot(QImage)
def setImage(self, image):
self.label.setPixmap(QPixmap.fromImage(image))
self.th.writer.write(image)
def main():
app = QApplication(sys.argv)
ex = MyApp()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
我也尝试将其.write()
放在 Thread 类的 run() 内部,这也显示了相同的错误。你们能指出我做错了什么以及如何让它发挥作用。我是 python 和 pyqt 的新手。提前致谢。
解决方案
您需要分离线程。第一个线程用于信号,第二个用于记录,主线程用于 GUI。试试下面的代码。有一个按钮可以开始/停止记录。
import sys
import cv2
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QLabel, QVBoxLayout
from PyQt5.QtGui import QImage, QPixmap
from PyQt5.QtCore import QTimer, QThread, pyqtSignal, pyqtSlot
from PyQt5 import QtWidgets, QtCore, QtGui
#https://ru.stackoverflow.com/a/1150993/396441
class Thread1(QThread):
changePixmap = pyqtSignal(QImage)
def __init__(self, *args, **kwargs):
super().__init__()
def run(self):
self.cap1 = cv2.VideoCapture(0, cv2.CAP_DSHOW)
self.cap1.set(3,480)
self.cap1.set(4,640)
self.cap1.set(5,30)
while True:
ret1, image1 = self.cap1.read()
if ret1:
im1 = cv2.cvtColor(image1, cv2.COLOR_BGR2RGB)
height1, width1, channel1 = im1.shape
step1 = channel1 * width1
qImg1 = QImage(im1.data, width1, height1, step1, QImage.Format_RGB888)
self.changePixmap.emit(qImg1)
class Thread2(QThread):
def __init__(self, *args, **kwargs):
super().__init__()
self.active = True
def run(self):
if self.active:
self.fourcc = cv2.VideoWriter_fourcc(*'XVID')
self.out1 = cv2.VideoWriter('output.avi', self.fourcc, 30, (640,480))
self.cap1 = cv2.VideoCapture(0, cv2.CAP_DSHOW)
self.cap1.set(3, 480)
self.cap1.set(4, 640)
self.cap1.set(5, 30)
while self.active:
ret1, image1 = self.cap1.read()
if ret1:
self.out1.write(image1)
self.msleep(10)
def stop(self):
self.out1.release()
class MainWindow(QWidget):
def __init__(self):
super().__init__()
self.resize(660, 520)
self.control_bt = QPushButton('START')
self.control_bt.clicked.connect(self.controlTimer)
self.image_label = QLabel()
self.saveTimer = QTimer()
self.th1 = Thread1(self)
self.th1.changePixmap.connect(self.setImage)
self.th1.start()
vlayout = QVBoxLayout(self)
vlayout.addWidget(self.image_label)
vlayout.addWidget(self.control_bt)
@QtCore.pyqtSlot(QImage)
def setImage(self, qImg1):
self.image_label.setPixmap(QPixmap.fromImage(qImg1))
def controlTimer(self):
if not self.saveTimer.isActive():
# write video
self.saveTimer.start()
self.th2 = Thread2(self)
self.th2.active = True
self.th2.start()
# update control_bt text
self.control_bt.setText("STOP")
else:
# stop writing
self.saveTimer.stop()
self.th2.active = False
self.th2.stop()
self.th2.terminate()
# update control_bt text
self.control_bt.setText("START")
if __name__ == '__main__':
app = QApplication(sys.argv)
mainWindow = MainWindow()
mainWindow.show()
sys.exit(app.exec_())
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