Add metabox with media uploader in a custom post type [duplicate]

I need to create a “media uploader metabox” and add it to my custom post type.
I’ve already create normal metaboxes, the function to add to the custom post type and the function to save them, I only need to use the wordpress’ media uploader but I can’t figured out how to do that.
After that I would insert something like “Add more image” that add more metaboxes into the page.

Something like that:

I am working on something similar. This is for a podcast upload meta-box. Returns the url to the file. Here is what I have so far:

//Add Metabox
add_action('add_meta_boxes', 'add_upload_file_metaboxes');

function add_upload_file_metaboxes() {
    add_meta_box('swp_file_upload', 'File Upload', 'swp_file_upload', 'podcasts', 'normal', 'default');
}


function swp_file_upload() {
    global $post;
    // Noncename needed to verify where the data originated
    echo '<input type="hidden" name="podcastmeta_noncename" id="podcastmeta_noncename" value="'.
    wp_create_nonce(plugin_basename(__FILE__)).
    '" />';
    global $wpdb;
    $strFile = get_post_meta($post -> ID, $key = 'podcast_file', true);
    $media_file = get_post_meta($post -> ID, $key = '_wp_attached_file', true);
    if (!empty($media_file)) {
        $strFile = $media_file;
    } ?>


    <script type = "text/javascript">

        // Uploading files
        var file_frame;
    jQuery('#upload_image_button').live('click', function(podcast) {

        podcast.preventDefault();

        // If the media frame already exists, reopen it.
        if (file_frame) {
            file_frame.open();
            return;
        }

        // Create the media frame.
        file_frame = wp.media.frames.file_frame = wp.media({
            title: jQuery(this).data('uploader_title'),
            button: {
                text: jQuery(this).data('uploader_button_text'),
            },
            multiple: false // Set to true to allow multiple files to be selected
        });

        // When a file is selected, run a callback.
        file_frame.on('select', function(){
            // We set multiple to false so only get one image from the uploader
            attachment = file_frame.state().get('selection').first().toJSON();

            // here are some of the variables you could use for the attachment;
            //var all = JSON.stringify( attachment );      
            //var id = attachment.id;
            //var title = attachment.title;
            //var filename = attachment.filename;
            var url = attachment.url;
            //var link = attachment.link;
            //var alt = attachment.alt;
            //var author = attachment.author;
            //var description = attachment.description;
            //var caption = attachment.caption;
            //var name = attachment.name;
            //var status = attachment.status;
            //var uploadedTo = attachment.uploadedTo;
            //var date = attachment.date;
            //var modified = attachment.modified;
            //var type = attachment.type;
            //var subtype = attachment.subtype;
            //var icon = attachment.icon;
            //var dateFormatted = attachment.dateFormatted;
            //var editLink = attachment.editLink;
            //var fileLength = attachment.fileLength;

            var field = document.getElementById("podcast_file");

            field.value = url; //set which variable you want the field to have
        });

        // Finally, open the modal
        file_frame.open();
    });

    </script>



    <div>

        <table>
        <tr valign = "top">
        <td>
        <input type = "text"
    name = "podcast_file"
    id = "podcast_file"
    size = "70"
    value = "<?php echo $strFile; ?>" />
        <input id = "upload_image_button"
    type = "button"
    value = "Upload">
        </td> </tr> </table> <input type = "hidden"
    name = "img_txt_id"
    id = "img_txt_id"
    value = "" />
        </div>     <?php
    function admin_scripts() {
        wp_enqueue_script('media-upload');
        wp_enqueue_script('thickbox');
    }

    function admin_styles() {
        wp_enqueue_style('thickbox');
    }
    add_action('admin_print_scripts', 'admin_scripts');
    add_action('admin_print_styles', 'admin_styles');
}


//Saving the file
function save_podcasts_meta($post_id, $post) {
    // verify this came from the our screen and with proper authorization,
    // because save_post can be triggered at other times
    if (!wp_verify_nonce($_POST['podcastmeta_noncename'], plugin_basename(__FILE__))) {
        return $post -> ID;
    }
    // Is the user allowed to edit the post?
    if (!current_user_can('edit_post', $post -> ID))
        return $post -> ID;
    // We need to find and save the data
    // We'll put it into an array to make it easier to loop though.
    $podcasts_meta['podcast_file'] = $_POST['podcast_file'];
    // Add values of $podcasts_meta as custom fields

    foreach($podcasts_meta as $key => $value) {
        if ($post -> post_type == 'revision') return;
        $value = implode(',', (array) $value);
        if (get_post_meta($post -> ID, $key, FALSE)) { // If the custom field already has a value it will update
            update_post_meta($post -> ID, $key, $value);
        } else { // If the custom field doesn't have a value it will add
            add_post_meta($post -> ID, $key, $value);
        }
        if (!$value) delete_post_meta($post -> ID, $key); // Delete if blank value
    }
}
add_action('save_post', 'save_podcasts_meta', 1, 2); // save the custom fields