如何在我的QmainWindow小工具中添加媒体播放器？

from PyQt5.QtMultimedia import QMediaPlayer, QMediaContent
from PyQt5.QtMultimediaWidgets import QVideoWidget

self.mediaPlayer = QMediaPlayer(self)
self.videoWidget = QVideoWidget(self)

self.mediaPlayer.setVideoOutput(self.videoWidget)
self.videoWidget.setGeometry(10, 10, 400, 300)  # 设置视频窗口的位置和大小

playButton = QPushButton("播放", self)
playButton.clicked.connect(self.playMedia)

selectButton = QPushButton("选择文件", self)
selectButton.clicked.connect(self.selectFile)

def playMedia(self):
    self.mediaPlayer.play()

def selectFile(self):
    file, _ = QFileDialog.getOpenFileName(self, "选择媒体文件", "", "媒体文件 (*.mp4 *.mp3)")
    if file:
        mediaContent = QMediaContent(QUrl.fromLocalFile(file))
        self.mediaPlayer.setMedia(mediaContent)

layout = QVBoxLayout()
layout.addWidget(self.videoWidget)
layout.addWidget(playButton)
layout.addWidget(selectButton)

centralWidget = QWidget()
centralWidget.setLayout(layout)
self.setCentralWidget(centralWidget)