Passing a small # shortcode [video] to # wordpress for all his videos responsive with the # css link above (http://webdesignerwall.com/tutorials/css-elastic-videos).
In the functions.php file add:

caption_shortcode function ($ atts, $ content = null) {
return '<div class="container-video">'. $ content. '</ div>';
}
add_shortcode ('video', 'caption_shortcode');



And after in the articles or posts surrounded the code from youtube without <iframe> width = "#" height = "#".

example

[video] <iframe src="http://www.youtube.com/embed/hOvGCrilWik" frameborder="0" allowfullscreen> </ iframe> [/ video]