angularjs ng-repeat image base64 from firebase

I have a collection of images base64 stored in a database firebase. The problem is that when the application fee ng-repeat takes about 20 seconds to show the images, I attached my code, can you help me please?

controller



    $scope.itinerarios = itinerariosFactory.getAll();

service



    .factory('itinerariosFactory', ['$firebase',
      function($firebase) {

        var ref = new Firebase('my firebase url');

        var itinerariosFactory = {
          getAll: function () {
              return $firebase(ref.child('itinerarios/')).$asArray();
          }
        };

        return itinerariosFactory;

      }])

view


    img ng-repeat="imagen in itinerario.imagenesSlider" data-ng-src="data:image/jpeg;base64,{{imagen.base64}}" width="100%"

Not sure if it helps, but you have to try (if you are using angular 1.3+)

data-ng-src="data:image/jpeg;base64,{{::imagen.base64}}"

Anyway, I don't think it's a good idea to add images in this way. Try adding a custom directive instead.