@mariusjopen Thanks, i did and used a css workaround:
<div class="container">
<iframe src="https://www.youtube.com/embed/live_stream?channel=UCslakCvwX60o10L5pK6VgfA"
frameborder="0" allowfullscreen class="video"></iframe>
</div>
.container {
position: relative;
width: 100%;
height: 0;
padding-bottom: 56.25%;
}
.video {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
}