width="560" height="315"

sandbox="allow-forms allow-scripts
                 allow-pointer-lock allow-same-origin allow-top-navigation"

<div class="bbMediaWrapper">
    <div class="bbMediaWrapper-inner">
<iframe src="https://www.youtube.com/embed/{$id}?wmode=opaque&start={$start}"
                width="560" height="315"
        sandbox="allow-forms allow-scripts
                 allow-pointer-lock allow-same-origin allow-top-navigation"
                frameborder="0" allowfullscreen="true"></iframe>
    </div>
</div>