How to remove the Oembed fixed hieght of 720px

How would I remove the fixed height for the video embeds? I see in the theme-functions.php there is a section that sets the xsb_embed_defaults and there’s a note to replace it with fitvids.js to automatically resize.

Using the embed default filter will resize the video’s however they are within a container that’s always 720px high no matter what the screen width is. The video maintains the proper aspect ratio as it resizes but the container that is 720px high has a solid black background.

Is there a simple way to remove the 720px height?

I also tried replacing the embed_defaults filter with fitvids.js but could not get it to work. Thanks