phonertc离子演示科尔多瓦未定义

我是ionic的新手，正在尝试在ionic平台上安装phonertc，但是当我运行该应用程序时，它对VideoViewDirective而言显示RefrenceError:cordova未定义.

I am a newbie with ionic and trying to install phonertc on ionic platform but when i run the app it shows for VideoViewDirective that RefrenceError: cordova is undefined.

VideoViewDirective.js

VideoViewDirective.js

angular.module('phonertcdemo')
  .directive('videoView', function ($rootScope, $timeout) {
return {
  restrict: 'E',
  template: '<div class="video-container"></div>',
  replace: true,
  link: function (scope, element, attrs) {
    function updatePosition() {
    cordova.plugins.phonertc.setVideoView({
        container: element[0],
        local: { 
          position: [240, 240],
          size: [50, 50]
        }
      });
    }

    $timeout(updatePosition, 500);
    $rootScope.$on('videoView.updatePosition', updatePosition);
  }
}
});