Wordpress File Uploader for images in custom post types

gistfile1.php

<?php 
/*******************************************************Podcast Meta-boxes  *******************/
//Add Metabox
//Source: http://wordpress.stackexchange.com/questions/139841/add-metabox-with-media-uploader-in-a-custom-post-type

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', 'videos', '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>

		<input type="text" name="podcast_file" id="podcast_file" size="70" value="<?php echo $strFile; ?>"/>
		<input id="upload_image_button" type="button" value="Upload">
		<input type="hidden" name="img_txt_id" id="img_txt_id" value=""/>

	<?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' );
}