title: How to set default sound value in youtube javascript api for video play on background?
body: <p>Here is JavaScript from <code>|* http://www.seanmccambridge.com/tubular</code> tutorial for video play at background.</p>
  
  <p>I have some defaults option that can I disable or enable video controller But I can't set default value to should value when user open my website.</p>
  
  <pre><code>;(function ($, window) {
  
      // test for feature support and return if failure
  
      // defaults
      var defaults = {
          ratio: 3/3, // usually either 4/3 or 16/9 -- tweak as needed
          videoId: '', // toy robot in space is a good default, no?
          mute: false,
          repeat: true,
          width: $(window).width(),
          wrapperZIndex: 99,
          playButtonClass: 'tubular-play',
          pauseButtonClass: 'tubular-pause',
          muteButtonClass: 'tubular-mute',
          volumeUpClass: 'tubular-volume-up',
          volumeDownClass: 'tubular-volume-down',
          increaseVolumeBy: 10,
          start: 0,
          Volume:10
      };
  
      // methods
  
      var tubular = function(node, options) { // should be called on the wrapper div
          var options = $.extend({}, defaults, options),
              $body = $('body') // cache body node
              $node = $(node); // cache wrapper node
  
          // build container
          var tubularContainer = '&lt;div id="tubular-container" style="  position: fixed; z-index: 1; width: 90%; height: 90%"&gt;&lt;div id="tubular-player" style="position: absolute"&gt;&lt;/div&gt;&lt;/div&gt;&lt;div id="tubular-shield" style="width:90%; height: 90%; z-index: 2; position: absolute; left: 0; top: 0;"&gt;&lt;/div&gt;';
  
          // set up CSS prereq's, inject tubular container and set up wrapper defaults
          $('html,body').css({'width': '90%', 'height': '90%'});
          $body.prepend(tubularContainer);
          $node.css({position: 'relative', 'z-index': options.wrapperZIndex});
  
          // set up iframe player, use global scope so YT api can talk
          window.player;
          window.onYouTubeIframeAPIReady = function() {
              player = new YT.Player('tubular-player', {
                  width: options.width,
                  height: Math.ceil(options.width / options.ratio),
                  videoId: options.videoId,
                  playerVars: {
                      controls: 0,
                      showinfo: 0,
                      modestbranding: 1,
                      wmode: 'transparent'
                  },
                  events: {
                      'onReady': onPlayerReady,
                      'onStateChange': onPlayerStateChange
                  }
              });
          }
  
          window.onPlayerReady = function(e) {
              resize();
              if (options.mute) e.target.mute();
              e.target.seekTo(options.start);
              e.target.playVideo();
          }
  
          window.onPlayerStateChange = function(state) {
              if (state.data === 0 &amp;&amp; options.repeat) { // video ended and repeat option is set true
                  player.seekTo(options.start); // restart
              }
          }
  
          // resize handler updates width, height and offset of player after resize/init
          var resize = function() {
              var width = $(window).width(),
                  pWidth, // player width, to be defined
                  height = $(window).height(),
                  pHeight, // player height, tbd
                  $tubularPlayer = $('#tubular-player');
  
              // when screen aspect ratio differs from video, video must center and underlay one dimension
  
              if (width / options.ratio &lt; height) { // if new video height &lt; window height (gap underneath)
                  pWidth = Math.ceil(height * options.ratio); // get new player width
                  $tubularPlayer.width(pWidth).height(height).css({left: (width - pWidth) / 2, top: 0}); // player width is greater, offset left; reset top
              } else { // new video width &lt; window width (gap to right)
                  pHeight = Math.ceil(width / options.ratio); // get new player height
                  $tubularPlayer.width(width).height(pHeight).css({left: 0, top: (height - pHeight) / 2}); // player height is greater, offset top; reset left
              }
  
          }
  
          // events
          $(window).on('resize.tubular', function() {
              resize();
          })
  
          $('body').on('click','.' + options.playButtonClass, function(e) { // play button
              e.preventDefault();
              player.playVideo();
          }).on('click', '.' + options.pauseButtonClass, function(e) { // pause button
              e.preventDefault();
              player.pauseVideo();
          }).on('click', '.' + options.muteButtonClass, function(e) { // mute button
              e.preventDefault();
              (player.isMuted()) ? player.unMute() : player.mute();
          }).on('click', '.' + options.volumeDownClass, function(e) { // volume down button
              e.preventDefault();
              var currentVolume = player.getVolume();
              if (currentVolume &lt; options.increaseVolumeBy) currentVolume = options.increaseVolumeBy;
              player.setVolume(currentVolume - options.increaseVolumeBy);
          }).on('click', '.' + options.volumeUpClass, function(e) { // volume up button
              e.preventDefault();
              if (player.isMuted()) player.unMute(); // if mute is on, unmute
              var currentVolume = player.getVolume();
              if (currentVolume &gt; 10 - options.increaseVolumeBy) currentVolume = 100 - options.increaseVolumeBy;
              player.setVolume(currentVolume + options.increaseVolumeBy);
          })
      }
  
      // load yt iframe js api
  
      var tag = document.createElement('script');
      tag.src = "//www.youtube.com/iframe_api";
      var firstScriptTag = document.getElementsByTagName('script')[0];
      firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
  
      // create plugin
  
      $.fn.tubular = function (options) {
          return this.each(function () {
              if (!$.data(this, 'tubular_instantiated')) { // let's only run one
                  $.data(this, 'tubular_instantiated', 
                  tubular(this, options));
              }
          });
      }
  
  })(jQuery, window);
  </code></pre>