var player;

function videoStateChange (event) {
  var state;
  var videoId = player.getVideoData()['video_id'];
  var seconds = Math.round (player.getCurrentTime());

  switch (event.data) {
    case -1: state = 'Unstarted'; break;
    case 0: state = 'Ended'; break;
    case 1: state = 'Playing'; break;
    case 2: state = 'Paused'; break;
    case 3: state = 'Buffering'; break;
    case 4: state = 'Cued'; break;
  }

  // Replace `console.log` with `_paq.push` to actually send to Piwik
  if (state === 'Paused') {      
    console.log (['trackEvent', 'Video', state, videoId, seconds]);
  } else {
    console.log (['trackEvent', 'Video', state, videoId]);
  }
}

function onYouTubeIframeAPIReady() {
  player = new YT.Player ('player', {
    height: '390',
    width: '640',
    videoId: 'M7lc1UVf-VE',
    events: {
      'onStateChange': videoStateChange
    }
  });
}