qt显示视频大小和位置

    QString path = QFileDialog::getOpenFileName(this, tr("选择视频"), ".", tr("Image Files(*.flv *.mp4)"));//得到视频路径
    mediaPlayer = new QMediaPlayer();
    layout_video = new QVBoxLayout;
    videoWidget = new QVideoWidget();
    layout_video->setMargin(1);
    //根据label_player尺寸设置播放区域
    videoWidget->resize(ui->label_player->size());
    layout_video->addWidget(videoWidget);
    ui->label_player->setLayout(layout_video);
     mediaPlayer->setVideoOutput(videoWidget);
     mediaPlayer->setMedia(QUrl::fromLocalFile(path));
     mediaPlayer->play();