Player example above with the pre-roll video uses Spanish language.
Additional language support can be added to the Video.js in multiple ways.Language support is described in detail on dedicated website http://docs.videojs.com/docs/guides/languages.html.
Video.js distribution package includes "lang" directory with multiple .json files, each representing certain language translation. For much easier use Nuevodevel also prepared appropriate javascript files with language translations and this makes very easy to load and apply custom language, just like Spanish (es.js) in the example below.
<script src="//domain.com/video-js/video.min.js"></script><script src="//domain.com/video-js/lang/es.js"></script><script src="//domain.com/video-js/nuevo.min.js"></script><script>var player = videojs('example_video_1',{language: 'es'});player.nuevo({//plugin options here});</script>