video-embed-cache.php

<?php

function get_my_video_embed( $post_id, $video_url ) {
    global $wp_embed;

    $key = '_my_video_' . md5( $video_url );
    $cache = get_post_meta( $post_id, $key, true );
    if ( ! empty( $cache ) )
        return $cache;
        
    $content = $wp_embed->run_shortcode( sprintf( '[embed]%s[/embed]', esc_url_raw( $video_url ) ) );    
    update_post_meta( $post_id, $key, $content );
    return $content;
}