将pyqtgraph导出为视频

import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np
import cv2

app = QtGui.QApplication([])
win = pg.GraphicsWindow(title="PyQtGraph Export Video")

plot = win.addPlot(title="Plot Title")

x = np.linspace(0, 10, 100)
y = np.sin(x)

plot.plot(x, y, pen='r')

fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640, 480))

def update():
    img = QtGui.QPixmap.grabWindow(win.winId())
    frame = cv2.cvtColor(np.array(img.toImage()), cv2.COLOR_RGB2BGR)
    out.write(frame)

timer = QtCore.QTimer()
timer.timeout.connect(update)
timer.start(50)  # 每50毫秒截取一帧

# 运行应用程序
if __name__ == '__main__':
    QtGui.QApplication.instance().exec_()

out.release()
app.quit()