<iframe width="100%" height="600" src="https://www.youtube.com/embed/_h4PJP6b_s8" frameborder="0" allowfullscreen></iframe>
Неопределенный
<iframe width="100%" height="600" src="https://www.youtube.com/embed/_h4PJP6b_s8" frameborder="0" allowfullscreen></iframe>