Thomas

Responsive Embed Videos allows you to easily add youtube or vimeo videos to your website using our shortcode like :
[rev video=’http://youtube.com/watch?v=whatever’] or [rev video=’http://vimeo.com/whatever’]
All videos embeded with this shortcode will be fully responsive.
Here is a list of the shortcode attributes :
video – default: none | This is the url of your video, from youtube or vimeo only for now.
width – default: 100% | This is the width ( in % ) of the player.
align – default: center, left, right | The horizontal alignment of the video.
ratio – default: 16/9 | This is the ratio we use to resize the player.
style – default: simple, normal | This is the style of the player.
Languages: English.
Disclaimer :
I can’t guarantee a 100% compatibility with advanced themes who may already make the embed videos responsive or with other video plugins.

Responsive Embed Videos

This plugins makes your embed videos included with its shortcode responsive. Compatible with Youtube and Vimeo.

Sibin Grasic

Responsive Videos plugin will allow you to automatically resize and scale your embedded videos on mobile devices. 
CSS selector option is provided so you can target only your post / page content container.
Features
<ul>
<li>Automatic configuration option</li>
<li>Automatically resizes / scales all your embedded videos</li>
<li>Works on all browsers</li>
<li>Highly compatible – you can change the css selector for the text highlight</li>
<li>Customizable – you can select the page type on which to activate the fitVids script</li>
</ul>

Responsive videos – Fitvids

Nice one

Good

Make your Embedded videos responsive on mobile devices with jQuery FitVids plugin

Responsive Embed Videos vs Responsive videos – Fitvids