获取值 标准类对象 PHP

我使用mp4数据提取php脚本。这将返回一个 stdClass 对象，如下所示。任何人都可以告诉我如何从下面的对象显示持续时间。谢谢

stdClass Object
(
    [hasVideo] => 1
    [hasAudio] => 1
    [video] => stdClass Object
        (
            [width] => 472
            [height] => 360
            [codec] => 224
            [codecStr] => H.264
        )

    [audio] => stdClass Object
        (
            [codec] => 224
            [codecStr] => AAC
        )

    [duration] => 622.8
)