Exclude rtMedia Uplaoded media form backend media tab

exclude-media.php

<?php 
/**
* Function will exclude all rtMedia uploaded media from backend media tab.
*/
function show_only_allowed_media( $query ) {
	global $wpdb, $pagenow;
	if ( $query->is_admin ) {
		if('upload.php' === $pagenow || ( !empty($_REQUEST['action']) && 'query-attachments' === $_REQUEST['action']) ){
			$wp_rt_rtm_media = $wpdb->prefix."rt_rtm_media";
			$custom_query = "select media_id from ".$wp_rt_rtm_media;
			// Get all rtMedia media Ids.
			$results = $wpdb->get_results($custom_query,ARRAY_A);
			$rtmedia_media_ids = array();
			if(!empty($results)){
				foreach ($results as $key => $value) {
					$rtmedia_media_ids[] = $value['media_id'];
				}					
				$query->set('post__not_in',  $rtmedia_media_ids );
			}
		}
	}
	return $query;
}
add_filter('pre_get_posts', 'show_only_allowed_media');