Supprimer les caractères spéciaux des media produit

public function store(&$data) {

		$data['virtuemart_media_id'] = $this->getId();
		if(!vmAccess::manager('media.edit')){
			vmWarn('Insufficient permission to store media');
			return false;
		} else if( empty($data['virtuemart_media_id']) and !vmAccess::manager('media.create')){
			vmWarn('Insufficient permission to create media');
			return false;
		}

		vmLanguage::loadJLang('com_virtuemart_media');
		if (!class_exists('VmMediaHandler')) require(VMPATH_ADMIN.DS.'helpers'.DS.'mediahandler.php');

		$table = $this->getTable('medias');

		$table->bind($data);
		$data = VmMediaHandler::prepareStoreMedia($table,$data,$data['file_type']); //this does not store the media, it process the actions and prepares data
        
       //Renomme le nom du fichier
       // Ici j'arrive à renommer le nom du fichier
        $data['file_title'] = JFile::makeSafe($data['file_title']);
        $data['file_title'] = str_replace(' ', '_', $data['file_title']);
        
        //Mais il me reste à modifier également les URL sans pour autant supprimer les slash
        $data['file_url'] = ????
        $data-['file_url_thumb'] = ????
      
		
        if($data===false) return $table->virtuemart_media_id;
		// workarround for media published and product published two fields in one form.
		$tmpPublished = false;
		if (isset($data['media_published'])){
			$tmpPublished = $data['published'];
			$data['published'] = $data['media_published'];
		}

		$table->bindChecknStore($data);

		if($tmpPublished){
			$data['published'] = $tmpPublished;
		}
		return $table->virtuemart_media_id;
	}