WordPress YT Shortcode Embed (Page Load Considered)

post.php

<?php
    echo do_shortcode('[youtube id="yXEfNoIZIP4"]');
?>

script.js

$(window).load(function(){
    $('iframe[data-src]').each(function(){
        $(this).attr('src', function(){
            return $(this).attr('data-src');
        });
    });
});

shortcode-yt.php

<?php
/****************************************     YOUTUBE    ****************************************/
add_shortcode('youtube', 'embed_youtube_videos');

function embed_youtube_videos($atts){
	ob_start();
	?>
		<iframe src="" data-src="https://www.youtube.com/embed/<?php echo $atts['id']; ?>" frameborder="0" allowfullscreen width="<?php echo $atts['width']; ?>" height="<?php echo $atts['height']; ?>"></iframe>
		
	<?php
	return ob_get_clean();
}
?>