text: (function (global, factory) {
  	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
  	typeof define === 'function' && define.amd ? define(['exports'], factory) :
  	(global = global || self, factory(global.ICanvasWeb = {}));
  }(this, (function (exports) { 'use strict';
  
  	/**
  	 * 获得一个canvas对象
  	 *
  	 * @param {String} key 特殊模版标识
  	 *
  	 * 打包模式为web时
  	 * key取main则该canvas将上屏
  	 */
  	function Canvas(width, height) {
  	  if (!Canvas.main) document.body.appendChild(Canvas.main = document.createElement('canvas'));
  	  if (width == 'main') return Canvas.main;
  	  var canvas = document.createElement('canvas');
  	  if (width > 0) canvas.width = width;
  	  if (height > 0) canvas.height = height;
  	  return canvas;
  	}
  
  	function loadFont(url) {
  	  var key = 'Font' + Date.now();
  	  var style = document.createElement('style');
  	  style.type = 'text/css';
  	  style.innerHTML = "\n            @font-face {\n                font-family: '".concat(key, "';\n                src: url('").concat(url, "'); \n            }\n            body {\n                font-family: '").concat(key, "';\n            }\n        ");
  	  document.body.appendChild(style);
  	  return key;
  	}
  
  	/**
  	 * 获取系统参数
  	 * pixel 屏幕与设备像素比
  	 * width 屏幕宽度
  	 * height 屏幕高度
  	 * ratio 宽高比
  	 */
  	function System() {
  	  System.pixel = window.devicePixelRatio || 2;
  	  System.width = document.body.clientWidth;
  	  System.height = document.body.clientHeight;
  	  System.ratio = System.width / System.height;
  	  return System;
  	}
  
  	function GetTouchEvent(MouseEvent) {
  	  return {
  	    identifier: 0,
  	    changedTouches: [{
  	      clientX: MouseEvent.clientX,
  	      clientY: MouseEvent.clientY
  	    }]
  	  };
  	}
  
  	function MouseListen() {
  	  return function (event) {
  	    var DownState = false;
  	    window.document.body.addEventListener('mousedown', function (e) {
  	      return DownState = true, event.start(GetTouchEvent(e));
  	    }, {
  	      passive: true
  	    });
  	    window.document.body.addEventListener('mousemove', function (e) {
  	      return DownState && event.move(GetTouchEvent(e));
  	    }, {
  	      passive: true
  	    });
  	    window.document.body.addEventListener('mouseup', function (e) {
  	      return DownState && (DownState = false, event.end(GetTouchEvent(e)));
  	    }, {
  	      passive: true
  	    });
  	    window.document.body.addEventListener('mouseout', function (e) {
  	      return DownState && (DownState = false, event.end(GetTouchEvent(e)));
  	    }, {
  	      passive: true
  	    });
  	  };
  	}
  	/**
  	 * 将dom元素触摸事件和Touch类进行关联
  	 * @param {HTMLElement} dom
  	 * @param {ICanvas.UtilTouch} Touch
  	 */
  
  
  	function TouchListen(useMouse) {
  	  if (useMouse) return MouseListen();
  	  return function (event) {
  	    window.document.body.addEventListener('touchstart', function (e) {
  	      return event.start(e);
  	    }, {
  	      passive: true
  	    });
  	    window.document.body.addEventListener('touchmove', function (e) {
  	      return event.move(e);
  	    }, {
  	      passive: true
  	    });
  	    window.document.body.addEventListener('touchend', function (e) {
  	      return event.end(e);
  	    }, {
  	      passive: true
  	    });
  	    window.document.body.addEventListener('touchcancel', function (e) {
  	      return event.end(e);
  	    }, {
  	      passive: true
  	    });
  	  };
  	}
  
  	function _classCallCheck(instance, Constructor) {
  	  if (!(instance instanceof Constructor)) {
  	    throw new TypeError("Cannot call a class as a function");
  	  }
  	}
  
  	var classCallCheck = _classCallCheck;
  
  	function _defineProperties(target, props) {
  	  for (var i = 0; i < props.length; i++) {
  	    var descriptor = props[i];
  	    descriptor.enumerable = descriptor.enumerable || false;
  	    descriptor.configurable = true;
  	    if ("value" in descriptor) descriptor.writable = true;
  	    Object.defineProperty(target, descriptor.key, descriptor);
  	  }
  	}
  
  	function _createClass(Constructor, protoProps, staticProps) {
  	  if (protoProps) _defineProperties(Constructor.prototype, protoProps);
  	  if (staticProps) _defineProperties(Constructor, staticProps);
  	  return Constructor;
  	}
  
  	var createClass = _createClass;
  
  	var Image =
  	/*#__PURE__*/
  	function () {
  	  function Image() {
  	    classCallCheck(this, Image);
  	  }
  
  	  createClass(Image, [{
  	    key: "load",
  	    value: function load(url) {
  	      return new Promise(function (resolve, reject) {
  	        var image = new window.Image();
  
  	        image.onload = function () {
  	          resolve(image);
  	        };
  
  	        image.onerror = function (e) {
  	          reject(e);
  	        };
  
  	        image.key = image.src = url;
  	      });
  	    }
  	  }]);
  
  	  return Image;
  	}();
  
  	var commonjsGlobal = typeof globalThis !== 'undefined' ? globalThis : typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};
  
  	function createCommonjsModule(fn, module) {
  		return module = { exports: {} }, fn(module, module.exports), module.exports;
  	}
  
  	var howler = createCommonjsModule(function (module, exports) {
  	/*!
  	 *  howler.js v2.1.2
  	 *  howlerjs.com
  	 *
  	 *  (c) 2013-2019, James Simpson of GoldFire Studios
  	 *  goldfirestudios.com
  	 *
  	 *  MIT License
  	 */
  
  	(function() {
  
  	  /** Global Methods **/
  	  /***************************************************************************/
  
  	  /**
  	   * Create the global controller. All contained methods and properties apply
  	   * to all sounds that are currently playing or will be in the future.
  	   */
  	  var HowlerGlobal = function() {
  	    this.init();
  	  };
  	  HowlerGlobal.prototype = {
  	    /**
  	     * Initialize the global Howler object.
  	     * @return {Howler}
  	     */
  	    init: function() {
  	      var self = this || Howler;
  
  	      // Create a global ID counter.
  	      self._counter = 1000;
  
  	      // Pool of unlocked HTML5 Audio objects.
  	      self._html5AudioPool = [];
  	      self.html5PoolSize = 10;
  
  	      // Internal properties.
  	      self._codecs = {};
  	      self._howls = [];
  	      self._muted = false;
  	      self._volume = 1;
  	      self._canPlayEvent = 'canplaythrough';
  	      self._navigator = (typeof window !== 'undefined' && window.navigator) ? window.navigator : null;
  
  	      // Public properties.
  	      self.masterGain = null;
  	      self.noAudio = false;
  	      self.usingWebAudio = true;
  	      self.autoSuspend = true;
  	      self.ctx = null;
  
  	      // Set to false to disable the auto audio unlocker.
  	      self.autoUnlock = true;
  
  	      // Setup the various state values for global tracking.
  	      self._setup();
  
  	      return self;
  	    },
  
  	    /**
  	     * Get/set the global volume for all sounds.
  	     * @param  {Float} vol Volume from 0.0 to 1.0.
  	     * @return {Howler/Float}     Returns self or current volume.
  	     */
  	    volume: function(vol) {
  	      var self = this || Howler;
  	      vol = parseFloat(vol);
  
  	      // If we don't have an AudioContext created yet, run the setup.
  	      if (!self.ctx) {
  	        setupAudioContext();
  	      }
  
  	      if (typeof vol !== 'undefined' && vol >= 0 && vol <= 1) {
  	        self._volume = vol;
  
  	        // Don't update any of the nodes if we are muted.
  	        if (self._muted) {
  	          return self;
  	        }
  
  	        // When using Web Audio, we just need to adjust the master gain.
  	        if (self.usingWebAudio) {
  	          self.masterGain.gain.setValueAtTime(vol, Howler.ctx.currentTime);
  	        }
  
  	        // Loop through and change volume for all HTML5 audio nodes.
  	        for (var i=0; i<self._howls.length; i++) {
  	          if (!self._howls[i]._webAudio) {
  	            // Get all of the sounds in this Howl group.
  	            var ids = self._howls[i]._getSoundIds();
  
  	            // Loop through all sounds and change the volumes.
  	            for (var j=0; j<ids.length; j++) {
  	              var sound = self._howls[i]._soundById(ids[j]);
  
  	              if (sound && sound._node) {
  	                sound._node.volume = sound._volume * vol;
  	              }
  	            }
  	          }
  	        }
  
  	        return self;
  	      }
  
  	      return self._volume;
  	    },
  
  	    /**
  	     * Handle muting and unmuting globally.
  	     * @param  {Boolean} muted Is muted or not.
  	     */
  	    mute: function(muted) {
  	      var self = this || Howler;
  
  	      // If we don't have an AudioContext created yet, run the setup.
  	      if (!self.ctx) {
  	        setupAudioContext();
  	      }
  
  	      self._muted = muted;
  
  	      // With Web Audio, we just need to mute the master gain.
  	      if (self.usingWebAudio) {
  	        self.masterGain.gain.setValueAtTime(muted ? 0 : self._volume, Howler.ctx.currentTime);
  	      }
  
  	      // Loop through and mute all HTML5 Audio nodes.
  	      for (var i=0; i<self._howls.length; i++) {
  	        if (!self._howls[i]._webAudio) {
  	          // Get all of the sounds in this Howl group.
  	          var ids = self._howls[i]._getSoundIds();
  
  	          // Loop through all sounds and mark the audio node as muted.
  	          for (var j=0; j<ids.length; j++) {
  	            var sound = self._howls[i]._soundById(ids[j]);
  
  	            if (sound && sound._node) {
  	              sound._node.muted = (muted) ? true : sound._muted;
  	            }
  	          }
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Unload and destroy all currently loaded Howl objects.
  	     * @return {Howler}
  	     */
  	    unload: function() {
  	      var self = this || Howler;
  
  	      for (var i=self._howls.length-1; i>=0; i--) {
  	        self._howls[i].unload();
  	      }
  
  	      // Create a new AudioContext to make sure it is fully reset.
  	      if (self.usingWebAudio && self.ctx && typeof self.ctx.close !== 'undefined') {
  	        self.ctx.close();
  	        self.ctx = null;
  	        setupAudioContext();
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Check for codec support of specific extension.
  	     * @param  {String} ext Audio file extention.
  	     * @return {Boolean}
  	     */
  	    codecs: function(ext) {
  	      return (this || Howler)._codecs[ext.replace(/^x-/, '')];
  	    },
  
  	    /**
  	     * Setup various state values for global tracking.
  	     * @return {Howler}
  	     */
  	    _setup: function() {
  	      var self = this || Howler;
  
  	      // Keeps track of the suspend/resume state of the AudioContext.
  	      self.state = self.ctx ? self.ctx.state || 'suspended' : 'suspended';
  
  	      // Automatically begin the 30-second suspend process
  	      self._autoSuspend();
  
  	      // Check if audio is available.
  	      if (!self.usingWebAudio) {
  	        // No audio is available on this system if noAudio is set to true.
  	        if (typeof Audio !== 'undefined') {
  	          try {
  	            var test = new Audio();
  
  	            // Check if the canplaythrough event is available.
  	            if (typeof test.oncanplaythrough === 'undefined') {
  	              self._canPlayEvent = 'canplay';
  	            }
  	          } catch(e) {
  	            self.noAudio = true;
  	          }
  	        } else {
  	          self.noAudio = true;
  	        }
  	      }
  
  	      // Test to make sure audio isn't disabled in Internet Explorer.
  	      try {
  	        var test = new Audio();
  	        if (test.muted) {
  	          self.noAudio = true;
  	        }
  	      } catch (e) {}
  
  	      // Check for supported codecs.
  	      if (!self.noAudio) {
  	        self._setupCodecs();
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Check for browser support for various codecs and cache the results.
  	     * @return {Howler}
  	     */
  	    _setupCodecs: function() {
  	      var self = this || Howler;
  	      var audioTest = null;
  
  	      // Must wrap in a try/catch because IE11 in server mode throws an error.
  	      try {
  	        audioTest = (typeof Audio !== 'undefined') ? new Audio() : null;
  	      } catch (err) {
  	        return self;
  	      }
  
  	      if (!audioTest || typeof audioTest.canPlayType !== 'function') {
  	        return self;
  	      }
  
  	      var mpegTest = audioTest.canPlayType('audio/mpeg;').replace(/^no$/, '');
  
  	      // Opera version <33 has mixed MP3 support, so we need to check for and block it.
  	      var checkOpera = self._navigator && self._navigator.userAgent.match(/OPR\/([0-6].)/g);
  	      var isOldOpera = (checkOpera && parseInt(checkOpera[0].split('/')[1], 10) < 33);
  
  	      self._codecs = {
  	        mp3: !!(!isOldOpera && (mpegTest || audioTest.canPlayType('audio/mp3;').replace(/^no$/, ''))),
  	        mpeg: !!mpegTest,
  	        opus: !!audioTest.canPlayType('audio/ogg; codecs="opus"').replace(/^no$/, ''),
  	        ogg: !!audioTest.canPlayType('audio/ogg; codecs="vorbis"').replace(/^no$/, ''),
  	        oga: !!audioTest.canPlayType('audio/ogg; codecs="vorbis"').replace(/^no$/, ''),
  	        wav: !!audioTest.canPlayType('audio/wav; codecs="1"').replace(/^no$/, ''),
  	        aac: !!audioTest.canPlayType('audio/aac;').replace(/^no$/, ''),
  	        caf: !!audioTest.canPlayType('audio/x-caf;').replace(/^no$/, ''),
  	        m4a: !!(audioTest.canPlayType('audio/x-m4a;') || audioTest.canPlayType('audio/m4a;') || audioTest.canPlayType('audio/aac;')).replace(/^no$/, ''),
  	        mp4: !!(audioTest.canPlayType('audio/x-mp4;') || audioTest.canPlayType('audio/mp4;') || audioTest.canPlayType('audio/aac;')).replace(/^no$/, ''),
  	        weba: !!audioTest.canPlayType('audio/webm; codecs="vorbis"').replace(/^no$/, ''),
  	        webm: !!audioTest.canPlayType('audio/webm; codecs="vorbis"').replace(/^no$/, ''),
  	        dolby: !!audioTest.canPlayType('audio/mp4; codecs="ec-3"').replace(/^no$/, ''),
  	        flac: !!(audioTest.canPlayType('audio/x-flac;') || audioTest.canPlayType('audio/flac;')).replace(/^no$/, '')
  	      };
  
  	      return self;
  	    },
  
  	    /**
  	     * Some browsers/devices will only allow audio to be played after a user interaction.
  	     * Attempt to automatically unlock audio on the first user interaction.
  	     * Concept from: http://paulbakaus.com/tutorials/html5/web-audio-on-ios/
  	     * @return {Howler}
  	     */
  	    _unlockAudio: function() {
  	      var self = this || Howler;
  
  	      // Only run this if Web Audio is supported and it hasn't already been unlocked.
  	      if (self._audioUnlocked || !self.ctx) {
  	        return;
  	      }
  
  	      self._audioUnlocked = false;
  	      self.autoUnlock = false;
  
  	      // Some mobile devices/platforms have distortion issues when opening/closing tabs and/or web views.
  	      // Bugs in the browser (especially Mobile Safari) can cause the sampleRate to change from 44100 to 48000.
  	      // By calling Howler.unload(), we create a new AudioContext with the correct sampleRate.
  	      if (!self._mobileUnloaded && self.ctx.sampleRate !== 44100) {
  	        self._mobileUnloaded = true;
  	        self.unload();
  	      }
  
  	      // Scratch buffer for enabling iOS to dispose of web audio buffers correctly, as per:
  	      // http://stackoverflow.com/questions/24119684
  	      self._scratchBuffer = self.ctx.createBuffer(1, 1, 22050);
  
  	      // Call this method on touch start to create and play a buffer,
  	      // then check if the audio actually played to determine if
  	      // audio has now been unlocked on iOS, Android, etc.
  	      var unlock = function(e) {
  	        // Create a pool of unlocked HTML5 Audio objects that can
  	        // be used for playing sounds without user interaction. HTML5
  	        // Audio objects must be individually unlocked, as opposed
  	        // to the WebAudio API which only needs a single activation.
  	        // This must occur before WebAudio setup or the source.onended
  	        // event will not fire.
  	        for (var i=0; i<self.html5PoolSize; i++) {
  	          try {
  	            var audioNode = new Audio();
  
  	            // Mark this Audio object as unlocked to ensure it can get returned
  	            // to the unlocked pool when released.
  	            audioNode._unlocked = true;
  
  	            // Add the audio node to the pool.
  	            self._releaseHtml5Audio(audioNode);
  	          } catch (e) {
  	            self.noAudio = true;
  	          }
  	        }
  
  	        // Loop through any assigned audio nodes and unlock them.
  	        for (var i=0; i<self._howls.length; i++) {
  	          if (!self._howls[i]._webAudio) {
  	            // Get all of the sounds in this Howl group.
  	            var ids = self._howls[i]._getSoundIds();
  
  	            // Loop through all sounds and unlock the audio nodes.
  	            for (var j=0; j<ids.length; j++) {
  	              var sound = self._howls[i]._soundById(ids[j]);
  
  	              if (sound && sound._node && !sound._node._unlocked) {
  	                sound._node._unlocked = true;
  	                sound._node.load();
  	              }
  	            }
  	          }
  	        }
  
  	        // Fix Android can not play in suspend state.
  	        self._autoResume();
  
  	        // Create an empty buffer.
  	        var source = self.ctx.createBufferSource();
  	        source.buffer = self._scratchBuffer;
  	        source.connect(self.ctx.destination);
  
  	        // Play the empty buffer.
  	        if (typeof source.start === 'undefined') {
  	          source.noteOn(0);
  	        } else {
  	          source.start(0);
  	        }
  
  	        // Calling resume() on a stack initiated by user gesture is what actually unlocks the audio on Android Chrome >= 55.
  	        if (typeof self.ctx.resume === 'function') {
  	          self.ctx.resume();
  	        }
  
  	        // Setup a timeout to check that we are unlocked on the next event loop.
  	        source.onended = function() {
  	          source.disconnect(0);
  
  	          // Update the unlocked state and prevent this check from happening again.
  	          self._audioUnlocked = true;
  
  	          // Remove the touch start listener.
  	          document.removeEventListener('touchstart', unlock, true);
  	          document.removeEventListener('touchend', unlock, true);
  	          document.removeEventListener('click', unlock, true);
  
  	          // Let all sounds know that audio has been unlocked.
  	          for (var i=0; i<self._howls.length; i++) {
  	            self._howls[i]._emit('unlock');
  	          }
  	        };
  	      };
  
  	      // Setup a touch start listener to attempt an unlock in.
  	      document.addEventListener('touchstart', unlock, true);
  	      document.addEventListener('touchend', unlock, true);
  	      document.addEventListener('click', unlock, true);
  
  	      return self;
  	    },
  
  	    /**
  	     * Get an unlocked HTML5 Audio object from the pool. If none are left,
  	     * return a new Audio object and throw a warning.
  	     * @return {Audio} HTML5 Audio object.
  	     */
  	    _obtainHtml5Audio: function() {
  	      var self = this || Howler;
  
  	      // Return the next object from the pool if one exists.
  	      if (self._html5AudioPool.length) {
  	        return self._html5AudioPool.pop();
  	      }
  
  	      //.Check if the audio is locked and throw a warning.
  	      var testPlay = new Audio().play();
  	      if (testPlay && typeof Promise !== 'undefined' && (testPlay instanceof Promise || typeof testPlay.then === 'function')) {
  	        testPlay.catch(function() {
  	          console.warn('HTML5 Audio pool exhausted, returning potentially locked audio object.');
  	        });
  	      }
  
  	      return new Audio();
  	    },
  
  	    /**
  	     * Return an activated HTML5 Audio object to the pool.
  	     * @return {Howler}
  	     */
  	    _releaseHtml5Audio: function(audio) {
  	      var self = this || Howler;
  
  	      // Don't add audio to the pool if we don't know if it has been unlocked.
  	      if (audio._unlocked) {
  	        self._html5AudioPool.push(audio);
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Automatically suspend the Web Audio AudioContext after no sound has played for 30 seconds.
  	     * This saves processing/energy and fixes various browser-specific bugs with audio getting stuck.
  	     * @return {Howler}
  	     */
  	    _autoSuspend: function() {
  	      var self = this;
  
  	      if (!self.autoSuspend || !self.ctx || typeof self.ctx.suspend === 'undefined' || !Howler.usingWebAudio) {
  	        return;
  	      }
  
  	      // Check if any sounds are playing.
  	      for (var i=0; i<self._howls.length; i++) {
  	        if (self._howls[i]._webAudio) {
  	          for (var j=0; j<self._howls[i]._sounds.length; j++) {
  	            if (!self._howls[i]._sounds[j]._paused) {
  	              return self;
  	            }
  	          }
  	        }
  	      }
  
  	      if (self._suspendTimer) {
  	        clearTimeout(self._suspendTimer);
  	      }
  
  	      // If no sound has played after 30 seconds, suspend the context.
  	      self._suspendTimer = setTimeout(function() {
  	        if (!self.autoSuspend) {
  	          return;
  	        }
  
  	        self._suspendTimer = null;
  	        self.state = 'suspending';
  	        self.ctx.suspend().then(function() {
  	          self.state = 'suspended';
  
  	          if (self._resumeAfterSuspend) {
  	            delete self._resumeAfterSuspend;
  	            self._autoResume();
  	          }
  	        });
  	      }, 30000);
  
  	      return self;
  	    },
  
  	    /**
  	     * Automatically resume the Web Audio AudioContext when a new sound is played.
  	     * @return {Howler}
  	     */
  	    _autoResume: function() {
  	      var self = this;
  
  	      if (!self.ctx || typeof self.ctx.resume === 'undefined' || !Howler.usingWebAudio) {
  	        return;
  	      }
  
  	      if (self.state === 'running' && self._suspendTimer) {
  	        clearTimeout(self._suspendTimer);
  	        self._suspendTimer = null;
  	      } else if (self.state === 'suspended') {
  	        self.ctx.resume().then(function() {
  	          self.state = 'running';
  
  	          // Emit to all Howls that the audio has resumed.
  	          for (var i=0; i<self._howls.length; i++) {
  	            self._howls[i]._emit('resume');
  	          }
  	        });
  
  	        if (self._suspendTimer) {
  	          clearTimeout(self._suspendTimer);
  	          self._suspendTimer = null;
  	        }
  	      } else if (self.state === 'suspending') {
  	        self._resumeAfterSuspend = true;
  	      }
  
  	      return self;
  	    }
  	  };
  
  	  // Setup the global audio controller.
  	  var Howler = new HowlerGlobal();
  
  	  /** Group Methods **/
  	  /***************************************************************************/
  
  	  /**
  	   * Create an audio group controller.
  	   * @param {Object} o Passed in properties for this group.
  	   */
  	  var Howl = function(o) {
  	    var self = this;
  
  	    // Throw an error if no source is provided.
  	    if (!o.src || o.src.length === 0) {
  	      console.error('An array of source files must be passed with any new Howl.');
  	      return;
  	    }
  
  	    self.init(o);
  	  };
  	  Howl.prototype = {
  	    /**
  	     * Initialize a new Howl group object.
  	     * @param  {Object} o Passed in properties for this group.
  	     * @return {Howl}
  	     */
  	    init: function(o) {
  	      var self = this;
  
  	      // If we don't have an AudioContext created yet, run the setup.
  	      if (!Howler.ctx) {
  	        setupAudioContext();
  	      }
  
  	      // Setup user-defined default properties.
  	      self._autoplay = o.autoplay || false;
  	      self._format = (typeof o.format !== 'string') ? o.format : [o.format];
  	      self._html5 = o.html5 || false;
  	      self._muted = o.mute || false;
  	      self._loop = o.loop || false;
  	      self._pool = o.pool || 5;
  	      self._preload = (typeof o.preload === 'boolean') ? o.preload : true;
  	      self._rate = o.rate || 1;
  	      self._sprite = o.sprite || {};
  	      self._src = (typeof o.src !== 'string') ? o.src : [o.src];
  	      self._volume = o.volume !== undefined ? o.volume : 1;
  	      self._xhrWithCredentials = o.xhrWithCredentials || false;
  
  	      // Setup all other default properties.
  	      self._duration = 0;
  	      self._state = 'unloaded';
  	      self._sounds = [];
  	      self._endTimers = {};
  	      self._queue = [];
  	      self._playLock = false;
  
  	      // Setup event listeners.
  	      self._onend = o.onend ? [{fn: o.onend}] : [];
  	      self._onfade = o.onfade ? [{fn: o.onfade}] : [];
  	      self._onload = o.onload ? [{fn: o.onload}] : [];
  	      self._onloaderror = o.onloaderror ? [{fn: o.onloaderror}] : [];
  	      self._onplayerror = o.onplayerror ? [{fn: o.onplayerror}] : [];
  	      self._onpause = o.onpause ? [{fn: o.onpause}] : [];
  	      self._onplay = o.onplay ? [{fn: o.onplay}] : [];
  	      self._onstop = o.onstop ? [{fn: o.onstop}] : [];
  	      self._onmute = o.onmute ? [{fn: o.onmute}] : [];
  	      self._onvolume = o.onvolume ? [{fn: o.onvolume}] : [];
  	      self._onrate = o.onrate ? [{fn: o.onrate}] : [];
  	      self._onseek = o.onseek ? [{fn: o.onseek}] : [];
  	      self._onunlock = o.onunlock ? [{fn: o.onunlock}] : [];
  	      self._onresume = [];
  
  	      // Web Audio or HTML5 Audio?
  	      self._webAudio = Howler.usingWebAudio && !self._html5;
  
  	      // Automatically try to enable audio.
  	      if (typeof Howler.ctx !== 'undefined' && Howler.ctx && Howler.autoUnlock) {
  	        Howler._unlockAudio();
  	      }
  
  	      // Keep track of this Howl group in the global controller.
  	      Howler._howls.push(self);
  
  	      // If they selected autoplay, add a play event to the load queue.
  	      if (self._autoplay) {
  	        self._queue.push({
  	          event: 'play',
  	          action: function() {
  	            self.play();
  	          }
  	        });
  	      }
  
  	      // Load the source file unless otherwise specified.
  	      if (self._preload) {
  	        self.load();
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Load the audio file.
  	     * @return {Howler}
  	     */
  	    load: function() {
  	      var self = this;
  	      var url = null;
  
  	      // If no audio is available, quit immediately.
  	      if (Howler.noAudio) {
  	        self._emit('loaderror', null, 'No audio support.');
  	        return;
  	      }
  
  	      // Make sure our source is in an array.
  	      if (typeof self._src === 'string') {
  	        self._src = [self._src];
  	      }
  
  	      // Loop through the sources and pick the first one that is compatible.
  	      for (var i=0; i<self._src.length; i++) {
  	        var ext, str;
  
  	        if (self._format && self._format[i]) {
  	          // If an extension was specified, use that instead.
  	          ext = self._format[i];
  	        } else {
  	          // Make sure the source is a string.
  	          str = self._src[i];
  	          if (typeof str !== 'string') {
  	            self._emit('loaderror', null, 'Non-string found in selected audio sources - ignoring.');
  	            continue;
  	          }
  
  	          // Extract the file extension from the URL or base64 data URI.
  	          ext = /^data:audio\/([^;,]+);/i.exec(str);
  	          if (!ext) {
  	            ext = /\.([^.]+)$/.exec(str.split('?', 1)[0]);
  	          }
  
  	          if (ext) {
  	            ext = ext[1].toLowerCase();
  	          }
  	        }
  
  	        // Log a warning if no extension was found.
  	        if (!ext) {
  	          console.warn('No file extension was found. Consider using the "format" property or specify an extension.');
  	        }
  
  	        // Check if this extension is available.
  	        if (ext && Howler.codecs(ext)) {
  	          url = self._src[i];
  	          break;
  	        }
  	      }
  
  	      if (!url) {
  	        self._emit('loaderror', null, 'No codec support for selected audio sources.');
  	        return;
  	      }
  
  	      self._src = url;
  	      self._state = 'loading';
  
  	      // If the hosting page is HTTPS and the source isn't,
  	      // drop down to HTML5 Audio to avoid Mixed Content errors.
  	      if (window.location.protocol === 'https:' && url.slice(0, 5) === 'http:') {
  	        self._html5 = true;
  	        self._webAudio = false;
  	      }
  
  	      // Create a new sound object and add it to the pool.
  	      new Sound(self);
  
  	      // Load and decode the audio data for playback.
  	      if (self._webAudio) {
  	        loadBuffer(self);
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Play a sound or resume previous playback.
  	     * @param  {String/Number} sprite   Sprite name for sprite playback or sound id to continue previous.
  	     * @param  {Boolean} internal Internal Use: true prevents event firing.
  	     * @return {Number}          Sound ID.
  	     */
  	    play: function(sprite, internal) {
  	      var self = this;
  	      var id = null;
  
  	      // Determine if a sprite, sound id or nothing was passed
  	      if (typeof sprite === 'number') {
  	        id = sprite;
  	        sprite = null;
  	      } else if (typeof sprite === 'string' && self._state === 'loaded' && !self._sprite[sprite]) {
  	        // If the passed sprite doesn't exist, do nothing.
  	        return null;
  	      } else if (typeof sprite === 'undefined') {
  	        // Use the default sound sprite (plays the full audio length).
  	        sprite = '__default';
  
  	        // Check if there is a single paused sound that isn't ended. 
  	        // If there is, play that sound. If not, continue as usual.  
  	        if (!self._playLock) {
  	          var num = 0;
  	          for (var i=0; i<self._sounds.length; i++) {
  	            if (self._sounds[i]._paused && !self._sounds[i]._ended) {
  	              num++;
  	              id = self._sounds[i]._id;
  	            }
  	          }
  
  	          if (num === 1) {
  	            sprite = null;
  	          } else {
  	            id = null;
  	          }
  	        }
  	      }
  
  	      // Get the selected node, or get one from the pool.
  	      var sound = id ? self._soundById(id) : self._inactiveSound();
  
  	      // If the sound doesn't exist, do nothing.
  	      if (!sound) {
  	        return null;
  	      }
  
  	      // Select the sprite definition.
  	      if (id && !sprite) {
  	        sprite = sound._sprite || '__default';
  	      }
  
  	      // If the sound hasn't loaded, we must wait to get the audio's duration.
  	      // We also need to wait to make sure we don't run into race conditions with
  	      // the order of function calls.
  	      if (self._state !== 'loaded') {
  	        // Set the sprite value on this sound.
  	        sound._sprite = sprite;
  
  	        // Mark this sound as not ended in case another sound is played before this one loads.
  	        sound._ended = false;
  
  	        // Add the sound to the queue to be played on load.
  	        var soundId = sound._id;
  	        self._queue.push({
  	          event: 'play',
  	          action: function() {
  	            self.play(soundId);
  	          }
  	        });
  
  	        return soundId;
  	      }
  
  	      // Don't play the sound if an id was passed and it is already playing.
  	      if (id && !sound._paused) {
  	        // Trigger the play event, in order to keep iterating through queue.
  	        if (!internal) {
  	          self._loadQueue('play');
  	        }
  
  	        return sound._id;
  	      }
  
  	      // Make sure the AudioContext isn't suspended, and resume it if it is.
  	      if (self._webAudio) {
  	        Howler._autoResume();
  	      }
  
  	      // Determine how long to play for and where to start playing.
  	      var seek = Math.max(0, sound._seek > 0 ? sound._seek : self._sprite[sprite][0] / 1000);
  	      var duration = Math.max(0, ((self._sprite[sprite][0] + self._sprite[sprite][1]) / 1000) - seek);
  	      var timeout = (duration * 1000) / Math.abs(sound._rate);
  	      var start = self._sprite[sprite][0] / 1000;
  	      var stop = (self._sprite[sprite][0] + self._sprite[sprite][1]) / 1000;
  	      var loop = !!(sound._loop || self._sprite[sprite][2]);
  	      sound._sprite = sprite;
  
  	      // Mark the sound as ended instantly so that this async playback
  	      // doesn't get grabbed by another call to play while this one waits to start.
  	      sound._ended = false;
  
  	      // Update the parameters of the sound.
  	      var setParams = function() {
  	        sound._paused = false;
  	        sound._seek = seek;
  	        sound._start = start;
  	        sound._stop = stop;
  	        sound._loop = loop;
  	      };
  
  	      // End the sound instantly if seek is at the end.
  	      if (seek >= stop) {
  	        self._ended(sound);
  	        return;
  	      }
  
  	      // Begin the actual playback.
  	      var node = sound._node;
  	      if (self._webAudio) {
  	        // Fire this when the sound is ready to play to begin Web Audio playback.
  	        var playWebAudio = function() {
  	          self._playLock = false;
  	          setParams();
  	          self._refreshBuffer(sound);
  
  	          // Setup the playback params.
  	          var vol = (sound._muted || self._muted) ? 0 : sound._volume;
  	          node.gain.setValueAtTime(vol, Howler.ctx.currentTime);
  	          sound._playStart = Howler.ctx.currentTime;
  
  	          // Play the sound using the supported method.
  	          if (typeof node.bufferSource.start === 'undefined') {
  	            sound._loop ? node.bufferSource.noteGrainOn(0, seek, 86400) : node.bufferSource.noteGrainOn(0, seek, duration);
  	          } else {
  	            sound._loop ? node.bufferSource.start(0, seek, 86400) : node.bufferSource.start(0, seek, duration);
  	          }
  
  	          // Start a new timer if none is present.
  	          if (timeout !== Infinity) {
  	            self._endTimers[sound._id] = setTimeout(self._ended.bind(self, sound), timeout);
  	          }
  
  	          if (!internal) {
  	            setTimeout(function() {
  	              self._emit('play', sound._id);
  	              self._loadQueue();
  	            }, 0);
  	          }
  	        };
  
  	        if (Howler.state === 'running') {
  	          playWebAudio();
  	        } else {
  	          self._playLock = true;
  
  	          // Wait for the audio context to resume before playing.
  	          self.once('resume', playWebAudio);
  
  	          // Cancel the end timer.
  	          self._clearTimer(sound._id);
  	        }
  	      } else {
  	        // Fire this when the sound is ready to play to begin HTML5 Audio playback.
  	        var playHtml5 = function() {
  	          node.currentTime = seek;
  	          node.muted = sound._muted || self._muted || Howler._muted || node.muted;
  	          node.volume = sound._volume * Howler.volume();
  	          node.playbackRate = sound._rate;
  
  	          // Some browsers will throw an error if this is called without user interaction.
  	          try {
  	            var play = node.play();
  
  	            // Support older browsers that don't support promises, and thus don't have this issue.
  	            if (play && typeof Promise !== 'undefined' && (play instanceof Promise || typeof play.then === 'function')) {
  	              // Implements a lock to prevent DOMException: The play() request was interrupted by a call to pause().
  	              self._playLock = true;
  
  	              // Set param values immediately.
  	              setParams();
  
  	              // Releases the lock and executes queued actions.
  	              play
  	                .then(function() {
  	                  self._playLock = false;
  	                  node._unlocked = true;
  	                  if (!internal) {
  	                    self._emit('play', sound._id);
  	                    self._loadQueue();
  	                  }
  	                })
  	                .catch(function() {
  	                  self._playLock = false;
  	                  self._emit('playerror', sound._id, 'Playback was unable to start. This is most commonly an issue ' +
  	                    'on mobile devices and Chrome where playback was not within a user interaction.');
  
  	                  // Reset the ended and paused values.
  	                  sound._ended = true;
  	                  sound._paused = true;
  	                });
  	            } else if (!internal) {
  	              self._playLock = false;
  	              setParams();
  	              self._emit('play', sound._id);
  	              self._loadQueue();
  	            }
  
  	            // Setting rate before playing won't work in IE, so we set it again here.
  	            node.playbackRate = sound._rate;
  
  	            // If the node is still paused, then we can assume there was a playback issue.
  	            if (node.paused) {
  	              self._emit('playerror', sound._id, 'Playback was unable to start. This is most commonly an issue ' +
  	                'on mobile devices and Chrome where playback was not within a user interaction.');
  	              return;
  	            }
  
  	            // Setup the end timer on sprites or listen for the ended event.
  	            if (sprite !== '__default' || sound._loop) {
  	              self._endTimers[sound._id] = setTimeout(self._ended.bind(self, sound), timeout);
  	            } else {
  	              self._endTimers[sound._id] = function() {
  	                // Fire ended on this audio node.
  	                self._ended(sound);
  
  	                // Clear this listener.
  	                node.removeEventListener('ended', self._endTimers[sound._id], false);
  	              };
  	              node.addEventListener('ended', self._endTimers[sound._id], false);
  	            }
  	          } catch (err) {
  	            self._emit('playerror', sound._id, err);
  	          }
  	        };
  
  	        // If this is streaming audio, make sure the src is set and load again.
  	        if (node.src === 'data:audio/wav;base64,UklGRigAAABXQVZFZm10IBIAAAABAAEARKwAAIhYAQACABAAAABkYXRhAgAAAAEA') {
  	          node.src = self._src;
  	          node.load();
  	        }
  
  	        // Play immediately if ready, or wait for the 'canplaythrough'e vent.
  	        var loadedNoReadyState = (window && window.ejecta) || (!node.readyState && Howler._navigator.isCocoonJS);
  	        if (node.readyState >= 3 || loadedNoReadyState) {
  	          playHtml5();
  	        } else {
  	          self._playLock = true;
  
  	          var listener = function() {
  	            // Begin playback.
  	            playHtml5();
  
  	            // Clear this listener.
  	            node.removeEventListener(Howler._canPlayEvent, listener, false);
  	          };
  	          node.addEventListener(Howler._canPlayEvent, listener, false);
  
  	          // Cancel the end timer.
  	          self._clearTimer(sound._id);
  	        }
  	      }
  
  	      return sound._id;
  	    },
  
  	    /**
  	     * Pause playback and save current position.
  	     * @param  {Number} id The sound ID (empty to pause all in group).
  	     * @return {Howl}
  	     */
  	    pause: function(id) {
  	      var self = this;
  
  	      // If the sound hasn't loaded or a play() promise is pending, add it to the load queue to pause when capable.
  	      if (self._state !== 'loaded' || self._playLock) {
  	        self._queue.push({
  	          event: 'pause',
  	          action: function() {
  	            self.pause(id);
  	          }
  	        });
  
  	        return self;
  	      }
  
  	      // If no id is passed, get all ID's to be paused.
  	      var ids = self._getSoundIds(id);
  
  	      for (var i=0; i<ids.length; i++) {
  	        // Clear the end timer.
  	        self._clearTimer(ids[i]);
  
  	        // Get the sound.
  	        var sound = self._soundById(ids[i]);
  
  	        if (sound && !sound._paused) {
  	          // Reset the seek position.
  	          sound._seek = self.seek(ids[i]);
  	          sound._rateSeek = 0;
  	          sound._paused = true;
  
  	          // Stop currently running fades.
  	          self._stopFade(ids[i]);
  
  	          if (sound._node) {
  	            if (self._webAudio) {
  	              // Make sure the sound has been created.
  	              if (!sound._node.bufferSource) {
  	                continue;
  	              }
  
  	              if (typeof sound._node.bufferSource.stop === 'undefined') {
  	                sound._node.bufferSource.noteOff(0);
  	              } else {
  	                sound._node.bufferSource.stop(0);
  	              }
  
  	              // Clean up the buffer source.
  	              self._cleanBuffer(sound._node);
  	            } else if (!isNaN(sound._node.duration) || sound._node.duration === Infinity) {
  	              sound._node.pause();
  	            }
  	          }
  	        }
  
  	        // Fire the pause event, unless `true` is passed as the 2nd argument.
  	        if (!arguments[1]) {
  	          self._emit('pause', sound ? sound._id : null);
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Stop playback and reset to start.
  	     * @param  {Number} id The sound ID (empty to stop all in group).
  	     * @param  {Boolean} internal Internal Use: true prevents event firing.
  	     * @return {Howl}
  	     */
  	    stop: function(id, internal) {
  	      var self = this;
  
  	      // If the sound hasn't loaded, add it to the load queue to stop when capable.
  	      if (self._state !== 'loaded' || self._playLock) {
  	        self._queue.push({
  	          event: 'stop',
  	          action: function() {
  	            self.stop(id);
  	          }
  	        });
  
  	        return self;
  	      }
  
  	      // If no id is passed, get all ID's to be stopped.
  	      var ids = self._getSoundIds(id);
  
  	      for (var i=0; i<ids.length; i++) {
  	        // Clear the end timer.
  	        self._clearTimer(ids[i]);
  
  	        // Get the sound.
  	        var sound = self._soundById(ids[i]);
  
  	        if (sound) {
  	          // Reset the seek position.
  	          sound._seek = sound._start || 0;
  	          sound._rateSeek = 0;
  	          sound._paused = true;
  	          sound._ended = true;
  
  	          // Stop currently running fades.
  	          self._stopFade(ids[i]);
  
  	          if (sound._node) {
  	            if (self._webAudio) {
  	              // Make sure the sound's AudioBufferSourceNode has been created.
  	              if (sound._node.bufferSource) {
  	                if (typeof sound._node.bufferSource.stop === 'undefined') {
  	                  sound._node.bufferSource.noteOff(0);
  	                } else {
  	                  sound._node.bufferSource.stop(0);
  	                }
  
  	                // Clean up the buffer source.
  	                self._cleanBuffer(sound._node);
  	              }
  	            } else if (!isNaN(sound._node.duration) || sound._node.duration === Infinity) {
  	              sound._node.currentTime = sound._start || 0;
  	              sound._node.pause();
  
  	              // If this is a live stream, stop download once the audio is stopped.
  	              if (sound._node.duration === Infinity) {
  	                self._clearSound(sound._node);
  	              }
  	            }
  	          }
  
  	          if (!internal) {
  	            self._emit('stop', sound._id);
  	          }
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Mute/unmute a single sound or all sounds in this Howl group.
  	     * @param  {Boolean} muted Set to true to mute and false to unmute.
  	     * @param  {Number} id    The sound ID to update (omit to mute/unmute all).
  	     * @return {Howl}
  	     */
  	    mute: function(muted, id) {
  	      var self = this;
  
  	      // If the sound hasn't loaded, add it to the load queue to mute when capable.
  	      if (self._state !== 'loaded'|| self._playLock) {
  	        self._queue.push({
  	          event: 'mute',
  	          action: function() {
  	            self.mute(muted, id);
  	          }
  	        });
  
  	        return self;
  	      }
  
  	      // If applying mute/unmute to all sounds, update the group's value.
  	      if (typeof id === 'undefined') {
  	        if (typeof muted === 'boolean') {
  	          self._muted = muted;
  	        } else {
  	          return self._muted;
  	        }
  	      }
  
  	      // If no id is passed, get all ID's to be muted.
  	      var ids = self._getSoundIds(id);
  
  	      for (var i=0; i<ids.length; i++) {
  	        // Get the sound.
  	        var sound = self._soundById(ids[i]);
  
  	        if (sound) {
  	          sound._muted = muted;
  
  	          // Cancel active fade and set the volume to the end value.
  	          if (sound._interval) {
  	            self._stopFade(sound._id);
  	          }
  
  	          if (self._webAudio && sound._node) {
  	            sound._node.gain.setValueAtTime(muted ? 0 : sound._volume, Howler.ctx.currentTime);
  	          } else if (sound._node) {
  	            sound._node.muted = Howler._muted ? true : muted;
  	          }
  
  	          self._emit('mute', sound._id);
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Get/set the volume of this sound or of the Howl group. This method can optionally take 0, 1 or 2 arguments.
  	     *   volume() -> Returns the group's volume value.
  	     *   volume(id) -> Returns the sound id's current volume.
  	     *   volume(vol) -> Sets the volume of all sounds in this Howl group.
  	     *   volume(vol, id) -> Sets the volume of passed sound id.
  	     * @return {Howl/Number} Returns self or current volume.
  	     */
  	    volume: function() {
  	      var self = this;
  	      var args = arguments;
  	      var vol, id;
  
  	      // Determine the values based on arguments.
  	      if (args.length === 0) {
  	        // Return the value of the groups' volume.
  	        return self._volume;
  	      } else if (args.length === 1 || args.length === 2 && typeof args[1] === 'undefined') {
  	        // First check if this is an ID, and if not, assume it is a new volume.
  	        var ids = self._getSoundIds();
  	        var index = ids.indexOf(args[0]);
  	        if (index >= 0) {
  	          id = parseInt(args[0], 10);
  	        } else {
  	          vol = parseFloat(args[0]);
  	        }
  	      } else if (args.length >= 2) {
  	        vol = parseFloat(args[0]);
  	        id = parseInt(args[1], 10);
  	      }
  
  	      // Update the volume or return the current volume.
  	      var sound;
  	      if (typeof vol !== 'undefined' && vol >= 0 && vol <= 1) {
  	        // If the sound hasn't loaded, add it to the load queue to change volume when capable.
  	        if (self._state !== 'loaded'|| self._playLock) {
  	          self._queue.push({
  	            event: 'volume',
  	            action: function() {
  	              self.volume.apply(self, args);
  	            }
  	          });
  
  	          return self;
  	        }
  
  	        // Set the group volume.
  	        if (typeof id === 'undefined') {
  	          self._volume = vol;
  	        }
  
  	        // Update one or all volumes.
  	        id = self._getSoundIds(id);
  	        for (var i=0; i<id.length; i++) {
  	          // Get the sound.
  	          sound = self._soundById(id[i]);
  
  	          if (sound) {
  	            sound._volume = vol;
  
  	            // Stop currently running fades.
  	            if (!args[2]) {
  	              self._stopFade(id[i]);
  	            }
  
  	            if (self._webAudio && sound._node && !sound._muted) {
  	              sound._node.gain.setValueAtTime(vol, Howler.ctx.currentTime);
  	            } else if (sound._node && !sound._muted) {
  	              sound._node.volume = vol * Howler.volume();
  	            }
  
  	            self._emit('volume', sound._id);
  	          }
  	        }
  	      } else {
  	        sound = id ? self._soundById(id) : self._sounds[0];
  	        return sound ? sound._volume : 0;
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Fade a currently playing sound between two volumes (if no id is passsed, all sounds will fade).
  	     * @param  {Number} from The value to fade from (0.0 to 1.0).
  	     * @param  {Number} to   The volume to fade to (0.0 to 1.0).
  	     * @param  {Number} len  Time in milliseconds to fade.
  	     * @param  {Number} id   The sound id (omit to fade all sounds).
  	     * @return {Howl}
  	     */
  	    fade: function(from, to, len, id) {
  	      var self = this;
  
  	      // If the sound hasn't loaded, add it to the load queue to fade when capable.
  	      if (self._state !== 'loaded' || self._playLock) {
  	        self._queue.push({
  	          event: 'fade',
  	          action: function() {
  	            self.fade(from, to, len, id);
  	          }
  	        });
  
  	        return self;
  	      }
  
  	      // Make sure the to/from/len values are numbers.
  	      from = parseFloat(from);
  	      to = parseFloat(to);
  	      len = parseFloat(len);
  
  	      // Set the volume to the start position.
  	      self.volume(from, id);
  
  	      // Fade the volume of one or all sounds.
  	      var ids = self._getSoundIds(id);
  	      for (var i=0; i<ids.length; i++) {
  	        // Get the sound.
  	        var sound = self._soundById(ids[i]);
  
  	        // Create a linear fade or fall back to timeouts with HTML5 Audio.
  	        if (sound) {
  	          // Stop the previous fade if no sprite is being used (otherwise, volume handles this).
  	          if (!id) {
  	            self._stopFade(ids[i]);
  	          }
  
  	          // If we are using Web Audio, let the native methods do the actual fade.
  	          if (self._webAudio && !sound._muted) {
  	            var currentTime = Howler.ctx.currentTime;
  	            var end = currentTime + (len / 1000);
  	            sound._volume = from;
  	            sound._node.gain.setValueAtTime(from, currentTime);
  	            sound._node.gain.linearRampToValueAtTime(to, end);
  	          }
  
  	          self._startFadeInterval(sound, from, to, len, ids[i], typeof id === 'undefined');
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Starts the internal interval to fade a sound.
  	     * @param  {Object} sound Reference to sound to fade.
  	     * @param  {Number} from The value to fade from (0.0 to 1.0).
  	     * @param  {Number} to   The volume to fade to (0.0 to 1.0).
  	     * @param  {Number} len  Time in milliseconds to fade.
  	     * @param  {Number} id   The sound id to fade.
  	     * @param  {Boolean} isGroup   If true, set the volume on the group.
  	     */
  	    _startFadeInterval: function(sound, from, to, len, id, isGroup) {
  	      var self = this;
  	      var vol = from;
  	      var diff = to - from;
  	      var steps = Math.abs(diff / 0.01);
  	      var stepLen = Math.max(4, (steps > 0) ? len / steps : len);
  	      var lastTick = Date.now();
  
  	      // Store the value being faded to.
  	      sound._fadeTo = to;
  
  	      // Update the volume value on each interval tick.
  	      sound._interval = setInterval(function() {
  	        // Update the volume based on the time since the last tick.
  	        var tick = (Date.now() - lastTick) / len;
  	        lastTick = Date.now();
  	        vol += diff * tick;
  
  	        // Make sure the volume is in the right bounds.
  	        vol = Math.max(0, vol);
  	        vol = Math.min(1, vol);
  
  	        // Round to within 2 decimal points.
  	        vol = Math.round(vol * 100) / 100;
  
  	        // Change the volume.
  	        if (self._webAudio) {
  	          sound._volume = vol;
  	        } else {
  	          self.volume(vol, sound._id, true);
  	        }
  
  	        // Set the group's volume.
  	        if (isGroup) {
  	          self._volume = vol;
  	        }
  
  	        // When the fade is complete, stop it and fire event.
  	        if ((to < from && vol <= to) || (to > from && vol >= to)) {
  	          clearInterval(sound._interval);
  	          sound._interval = null;
  	          sound._fadeTo = null;
  	          self.volume(to, sound._id);
  	          self._emit('fade', sound._id);
  	        }
  	      }, stepLen);
  	    },
  
  	    /**
  	     * Internal method that stops the currently playing fade when
  	     * a new fade starts, volume is changed or the sound is stopped.
  	     * @param  {Number} id The sound id.
  	     * @return {Howl}
  	     */
  	    _stopFade: function(id) {
  	      var self = this;
  	      var sound = self._soundById(id);
  
  	      if (sound && sound._interval) {
  	        if (self._webAudio) {
  	          sound._node.gain.cancelScheduledValues(Howler.ctx.currentTime);
  	        }
  
  	        clearInterval(sound._interval);
  	        sound._interval = null;
  	        self.volume(sound._fadeTo, id);
  	        sound._fadeTo = null;
  	        self._emit('fade', id);
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Get/set the loop parameter on a sound. This method can optionally take 0, 1 or 2 arguments.
  	     *   loop() -> Returns the group's loop value.
  	     *   loop(id) -> Returns the sound id's loop value.
  	     *   loop(loop) -> Sets the loop value for all sounds in this Howl group.
  	     *   loop(loop, id) -> Sets the loop value of passed sound id.
  	     * @return {Howl/Boolean} Returns self or current loop value.
  	     */
  	    loop: function() {
  	      var self = this;
  	      var args = arguments;
  	      var loop, id, sound;
  
  	      // Determine the values for loop and id.
  	      if (args.length === 0) {
  	        // Return the grou's loop value.
  	        return self._loop;
  	      } else if (args.length === 1) {
  	        if (typeof args[0] === 'boolean') {
  	          loop = args[0];
  	          self._loop = loop;
  	        } else {
  	          // Return this sound's loop value.
  	          sound = self._soundById(parseInt(args[0], 10));
  	          return sound ? sound._loop : false;
  	        }
  	      } else if (args.length === 2) {
  	        loop = args[0];
  	        id = parseInt(args[1], 10);
  	      }
  
  	      // If no id is passed, get all ID's to be looped.
  	      var ids = self._getSoundIds(id);
  	      for (var i=0; i<ids.length; i++) {
  	        sound = self._soundById(ids[i]);
  
  	        if (sound) {
  	          sound._loop = loop;
  	          if (self._webAudio && sound._node && sound._node.bufferSource) {
  	            sound._node.bufferSource.loop = loop;
  	            if (loop) {
  	              sound._node.bufferSource.loopStart = sound._start || 0;
  	              sound._node.bufferSource.loopEnd = sound._stop;
  	            }
  	          }
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Get/set the playback rate of a sound. This method can optionally take 0, 1 or 2 arguments.
  	     *   rate() -> Returns the first sound node's current playback rate.
  	     *   rate(id) -> Returns the sound id's current playback rate.
  	     *   rate(rate) -> Sets the playback rate of all sounds in this Howl group.
  	     *   rate(rate, id) -> Sets the playback rate of passed sound id.
  	     * @return {Howl/Number} Returns self or the current playback rate.
  	     */
  	    rate: function() {
  	      var self = this;
  	      var args = arguments;
  	      var rate, id;
  
  	      // Determine the values based on arguments.
  	      if (args.length === 0) {
  	        // We will simply return the current rate of the first node.
  	        id = self._sounds[0]._id;
  	      } else if (args.length === 1) {
  	        // First check if this is an ID, and if not, assume it is a new rate value.
  	        var ids = self._getSoundIds();
  	        var index = ids.indexOf(args[0]);
  	        if (index >= 0) {
  	          id = parseInt(args[0], 10);
  	        } else {
  	          rate = parseFloat(args[0]);
  	        }
  	      } else if (args.length === 2) {
  	        rate = parseFloat(args[0]);
  	        id = parseInt(args[1], 10);
  	      }
  
  	      // Update the playback rate or return the current value.
  	      var sound;
  	      if (typeof rate === 'number') {
  	        // If the sound hasn't loaded, add it to the load queue to change playback rate when capable.
  	        if (self._state !== 'loaded' || self._playLock) {
  	          self._queue.push({
  	            event: 'rate',
  	            action: function() {
  	              self.rate.apply(self, args);
  	            }
  	          });
  
  	          return self;
  	        }
  
  	        // Set the group rate.
  	        if (typeof id === 'undefined') {
  	          self._rate = rate;
  	        }
  
  	        // Update one or all volumes.
  	        id = self._getSoundIds(id);
  	        for (var i=0; i<id.length; i++) {
  	          // Get the sound.
  	          sound = self._soundById(id[i]);
  
  	          if (sound) {
  	            // Keep track of our position when the rate changed and update the playback
  	            // start position so we can properly adjust the seek position for time elapsed.
  	            if (self.playing(id[i])) {
  	              sound._rateSeek = self.seek(id[i]);
  	              sound._playStart = self._webAudio ? Howler.ctx.currentTime : sound._playStart;
  	            }
  	            sound._rate = rate;
  
  	            // Change the playback rate.
  	            if (self._webAudio && sound._node && sound._node.bufferSource) {
  	              sound._node.bufferSource.playbackRate.setValueAtTime(rate, Howler.ctx.currentTime);
  	            } else if (sound._node) {
  	              sound._node.playbackRate = rate;
  	            }
  
  	            // Reset the timers.
  	            var seek = self.seek(id[i]);
  	            var duration = ((self._sprite[sound._sprite][0] + self._sprite[sound._sprite][1]) / 1000) - seek;
  	            var timeout = (duration * 1000) / Math.abs(sound._rate);
  
  	            // Start a new end timer if sound is already playing.
  	            if (self._endTimers[id[i]] || !sound._paused) {
  	              self._clearTimer(id[i]);
  	              self._endTimers[id[i]] = setTimeout(self._ended.bind(self, sound), timeout);
  	            }
  
  	            self._emit('rate', sound._id);
  	          }
  	        }
  	      } else {
  	        sound = self._soundById(id);
  	        return sound ? sound._rate : self._rate;
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Get/set the seek position of a sound. This method can optionally take 0, 1 or 2 arguments.
  	     *   seek() -> Returns the first sound node's current seek position.
  	     *   seek(id) -> Returns the sound id's current seek position.
  	     *   seek(seek) -> Sets the seek position of the first sound node.
  	     *   seek(seek, id) -> Sets the seek position of passed sound id.
  	     * @return {Howl/Number} Returns self or the current seek position.
  	     */
  	    seek: function() {
  	      var self = this;
  	      var args = arguments;
  	      var seek, id;
  
  	      // Determine the values based on arguments.
  	      if (args.length === 0) {
  	        // We will simply return the current position of the first node.
  	        id = self._sounds[0]._id;
  	      } else if (args.length === 1) {
  	        // First check if this is an ID, and if not, assume it is a new seek position.
  	        var ids = self._getSoundIds();
  	        var index = ids.indexOf(args[0]);
  	        if (index >= 0) {
  	          id = parseInt(args[0], 10);
  	        } else if (self._sounds.length) {
  	          id = self._sounds[0]._id;
  	          seek = parseFloat(args[0]);
  	        }
  	      } else if (args.length === 2) {
  	        seek = parseFloat(args[0]);
  	        id = parseInt(args[1], 10);
  	      }
  
  	      // If there is no ID, bail out.
  	      if (typeof id === 'undefined') {
  	        return self;
  	      }
  
  	      // If the sound hasn't loaded, add it to the load queue to seek when capable.
  	      if (self._state !== 'loaded' || self._playLock) {
  	        self._queue.push({
  	          event: 'seek',
  	          action: function() {
  	            self.seek.apply(self, args);
  	          }
  	        });
  
  	        return self;
  	      }
  
  	      // Get the sound.
  	      var sound = self._soundById(id);
  
  	      if (sound) {
  	        if (typeof seek === 'number' && seek >= 0) {
  	          // Pause the sound and update position for restarting playback.
  	          var playing = self.playing(id);
  	          if (playing) {
  	            self.pause(id, true);
  	          }
  
  	          // Move the position of the track and cancel timer.
  	          sound._seek = seek;
  	          sound._ended = false;
  	          self._clearTimer(id);
  
  	          // Update the seek position for HTML5 Audio.
  	          if (!self._webAudio && sound._node && !isNaN(sound._node.duration)) {
  	            sound._node.currentTime = seek;
  	          }
  
  	          // Seek and emit when ready.
  	          var seekAndEmit = function() {
  	            self._emit('seek', id);
  
  	            // Restart the playback if the sound was playing.
  	            if (playing) {
  	              self.play(id, true);
  	            }
  	          };
  
  	          // Wait for the play lock to be unset before emitting (HTML5 Audio).
  	          if (playing && !self._webAudio) {
  	            var emitSeek = function() {
  	              if (!self._playLock) {
  	                seekAndEmit();
  	              } else {
  	                setTimeout(emitSeek, 0);
  	              }
  	            };
  	            setTimeout(emitSeek, 0);
  	          } else {
  	            seekAndEmit();
  	          }
  	        } else {
  	          if (self._webAudio) {
  	            var realTime = self.playing(id) ? Howler.ctx.currentTime - sound._playStart : 0;
  	            var rateSeek = sound._rateSeek ? sound._rateSeek - sound._seek : 0;
  	            return sound._seek + (rateSeek + realTime * Math.abs(sound._rate));
  	          } else {
  	            return sound._node.currentTime;
  	          }
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Check if a specific sound is currently playing or not (if id is provided), or check if at least one of the sounds in the group is playing or not.
  	     * @param  {Number}  id The sound id to check. If none is passed, the whole sound group is checked.
  	     * @return {Boolean} True if playing and false if not.
  	     */
  	    playing: function(id) {
  	      var self = this;
  
  	      // Check the passed sound ID (if any).
  	      if (typeof id === 'number') {
  	        var sound = self._soundById(id);
  	        return sound ? !sound._paused : false;
  	      }
  
  	      // Otherwise, loop through all sounds and check if any are playing.
  	      for (var i=0; i<self._sounds.length; i++) {
  	        if (!self._sounds[i]._paused) {
  	          return true;
  	        }
  	      }
  
  	      return false;
  	    },
  
  	    /**
  	     * Get the duration of this sound. Passing a sound id will return the sprite duration.
  	     * @param  {Number} id The sound id to check. If none is passed, return full source duration.
  	     * @return {Number} Audio duration in seconds.
  	     */
  	    duration: function(id) {
  	      var self = this;
  	      var duration = self._duration;
  
  	      // If we pass an ID, get the sound and return the sprite length.
  	      var sound = self._soundById(id);
  	      if (sound) {
  	        duration = self._sprite[sound._sprite][1] / 1000;
  	      }
  
  	      return duration;
  	    },
  
  	    /**
  	     * Returns the current loaded state of this Howl.
  	     * @return {String} 'unloaded', 'loading', 'loaded'
  	     */
  	    state: function() {
  	      return this._state;
  	    },
  
  	    /**
  	     * Unload and destroy the current Howl object.
  	     * This will immediately stop all sound instances attached to this group.
  	     */
  	    unload: function() {
  	      var self = this;
  
  	      // Stop playing any active sounds.
  	      var sounds = self._sounds;
  	      for (var i=0; i<sounds.length; i++) {
  	        // Stop the sound if it is currently playing.
  	        if (!sounds[i]._paused) {
  	          self.stop(sounds[i]._id);
  	        }
  
  	        // Remove the source or disconnect.
  	        if (!self._webAudio) {
  	          // Set the source to 0-second silence to stop any downloading (except in IE).
  	          self._clearSound(sounds[i]._node);
  
  	          // Remove any event listeners.
  	          sounds[i]._node.removeEventListener('error', sounds[i]._errorFn, false);
  	          sounds[i]._node.removeEventListener(Howler._canPlayEvent, sounds[i]._loadFn, false);
  
  	          // Release the Audio object back to the pool.
  	          Howler._releaseHtml5Audio(sounds[i]._node);
  	        }
  
  	        // Empty out all of the nodes.
  	        delete sounds[i]._node;
  
  	        // Make sure all timers are cleared out.
  	        self._clearTimer(sounds[i]._id);
  	      }
  
  	      // Remove the references in the global Howler object.
  	      var index = Howler._howls.indexOf(self);
  	      if (index >= 0) {
  	        Howler._howls.splice(index, 1);
  	      }
  
  	      // Delete this sound from the cache (if no other Howl is using it).
  	      var remCache = true;
  	      for (i=0; i<Howler._howls.length; i++) {
  	        if (Howler._howls[i]._src === self._src || self._src.indexOf(Howler._howls[i]._src) >= 0) {
  	          remCache = false;
  	          break;
  	        }
  	      }
  
  	      if (cache && remCache) {
  	        delete cache[self._src];
  	      }
  
  	      // Clear global errors.
  	      Howler.noAudio = false;
  
  	      // Clear out `self`.
  	      self._state = 'unloaded';
  	      self._sounds = [];
  	      self = null;
  
  	      return null;
  	    },
  
  	    /**
  	     * Listen to a custom event.
  	     * @param  {String}   event Event name.
  	     * @param  {Function} fn    Listener to call.
  	     * @param  {Number}   id    (optional) Only listen to events for this sound.
  	     * @param  {Number}   once  (INTERNAL) Marks event to fire only once.
  	     * @return {Howl}
  	     */
  	    on: function(event, fn, id, once) {
  	      var self = this;
  	      var events = self['_on' + event];
  
  	      if (typeof fn === 'function') {
  	        events.push(once ? {id: id, fn: fn, once: once} : {id: id, fn: fn});
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Remove a custom event. Call without parameters to remove all events.
  	     * @param  {String}   event Event name.
  	     * @param  {Function} fn    Listener to remove. Leave empty to remove all.
  	     * @param  {Number}   id    (optional) Only remove events for this sound.
  	     * @return {Howl}
  	     */
  	    off: function(event, fn, id) {
  	      var self = this;
  	      var events = self['_on' + event];
  	      var i = 0;
  
  	      // Allow passing just an event and ID.
  	      if (typeof fn === 'number') {
  	        id = fn;
  	        fn = null;
  	      }
  
  	      if (fn || id) {
  	        // Loop through event store and remove the passed function.
  	        for (i=0; i<events.length; i++) {
  	          var isId = (id === events[i].id);
  	          if (fn === events[i].fn && isId || !fn && isId) {
  	            events.splice(i, 1);
  	            break;
  	          }
  	        }
  	      } else if (event) {
  	        // Clear out all events of this type.
  	        self['_on' + event] = [];
  	      } else {
  	        // Clear out all events of every type.
  	        var keys = Object.keys(self);
  	        for (i=0; i<keys.length; i++) {
  	          if ((keys[i].indexOf('_on') === 0) && Array.isArray(self[keys[i]])) {
  	            self[keys[i]] = [];
  	          }
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Listen to a custom event and remove it once fired.
  	     * @param  {String}   event Event name.
  	     * @param  {Function} fn    Listener to call.
  	     * @param  {Number}   id    (optional) Only listen to events for this sound.
  	     * @return {Howl}
  	     */
  	    once: function(event, fn, id) {
  	      var self = this;
  
  	      // Setup the event listener.
  	      self.on(event, fn, id, 1);
  
  	      return self;
  	    },
  
  	    /**
  	     * Emit all events of a specific type and pass the sound id.
  	     * @param  {String} event Event name.
  	     * @param  {Number} id    Sound ID.
  	     * @param  {Number} msg   Message to go with event.
  	     * @return {Howl}
  	     */
  	    _emit: function(event, id, msg) {
  	      var self = this;
  	      var events = self['_on' + event];
  
  	      // Loop through event store and fire all functions.
  	      for (var i=events.length-1; i>=0; i--) {
  	        // Only fire the listener if the correct ID is used.
  	        if (!events[i].id || events[i].id === id || event === 'load') {
  	          setTimeout(function(fn) {
  	            fn.call(this, id, msg);
  	          }.bind(self, events[i].fn), 0);
  
  	          // If this event was setup with `once`, remove it.
  	          if (events[i].once) {
  	            self.off(event, events[i].fn, events[i].id);
  	          }
  	        }
  	      }
  
  	      // Pass the event type into load queue so that it can continue stepping.
  	      self._loadQueue(event);
  
  	      return self;
  	    },
  
  	    /**
  	     * Queue of actions initiated before the sound has loaded.
  	     * These will be called in sequence, with the next only firing
  	     * after the previous has finished executing (even if async like play).
  	     * @return {Howl}
  	     */
  	    _loadQueue: function(event) {
  	      var self = this;
  
  	      if (self._queue.length > 0) {
  	        var task = self._queue[0];
  
  	        // Remove this task if a matching event was passed.
  	        if (task.event === event) {
  	          self._queue.shift();
  	          self._loadQueue();
  	        }
  
  	        // Run the task if no event type is passed.
  	        if (!event) {
  	          task.action();
  	        }
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Fired when playback ends at the end of the duration.
  	     * @param  {Sound} sound The sound object to work with.
  	     * @return {Howl}
  	     */
  	    _ended: function(sound) {
  	      var self = this;
  	      var sprite = sound._sprite;
  
  	      // If we are using IE and there was network latency we may be clipping
  	      // audio before it completes playing. Lets check the node to make sure it
  	      // believes it has completed, before ending the playback.
  	      if (!self._webAudio && sound._node && !sound._node.paused && !sound._node.ended && sound._node.currentTime < sound._stop) {
  	        setTimeout(self._ended.bind(self, sound), 100);
  	        return self;
  	      }
  
  	      // Should this sound loop?
  	      var loop = !!(sound._loop || self._sprite[sprite][2]);
  
  	      // Fire the ended event.
  	      self._emit('end', sound._id);
  
  	      // Restart the playback for HTML5 Audio loop.
  	      if (!self._webAudio && loop) {
  	        self.stop(sound._id, true).play(sound._id);
  	      }
  
  	      // Restart this timer if on a Web Audio loop.
  	      if (self._webAudio && loop) {
  	        self._emit('play', sound._id);
  	        sound._seek = sound._start || 0;
  	        sound._rateSeek = 0;
  	        sound._playStart = Howler.ctx.currentTime;
  
  	        var timeout = ((sound._stop - sound._start) * 1000) / Math.abs(sound._rate);
  	        self._endTimers[sound._id] = setTimeout(self._ended.bind(self, sound), timeout);
  	      }
  
  	      // Mark the node as paused.
  	      if (self._webAudio && !loop) {
  	        sound._paused = true;
  	        sound._ended = true;
  	        sound._seek = sound._start || 0;
  	        sound._rateSeek = 0;
  	        self._clearTimer(sound._id);
  
  	        // Clean up the buffer source.
  	        self._cleanBuffer(sound._node);
  
  	        // Attempt to auto-suspend AudioContext if no sounds are still playing.
  	        Howler._autoSuspend();
  	      }
  
  	      // When using a sprite, end the track.
  	      if (!self._webAudio && !loop) {
  	        self.stop(sound._id, true);
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Clear the end timer for a sound playback.
  	     * @param  {Number} id The sound ID.
  	     * @return {Howl}
  	     */
  	    _clearTimer: function(id) {
  	      var self = this;
  
  	      if (self._endTimers[id]) {
  	        // Clear the timeout or remove the ended listener.
  	        if (typeof self._endTimers[id] !== 'function') {
  	          clearTimeout(self._endTimers[id]);
  	        } else {
  	          var sound = self._soundById(id);
  	          if (sound && sound._node) {
  	            sound._node.removeEventListener('ended', self._endTimers[id], false);
  	          }
  	        }
  
  	        delete self._endTimers[id];
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Return the sound identified by this ID, or return null.
  	     * @param  {Number} id Sound ID
  	     * @return {Object}    Sound object or null.
  	     */
  	    _soundById: function(id) {
  	      var self = this;
  
  	      // Loop through all sounds and find the one with this ID.
  	      for (var i=0; i<self._sounds.length; i++) {
  	        if (id === self._sounds[i]._id) {
  	          return self._sounds[i];
  	        }
  	      }
  
  	      return null;
  	    },
  
  	    /**
  	     * Return an inactive sound from the pool or create a new one.
  	     * @return {Sound} Sound playback object.
  	     */
  	    _inactiveSound: function() {
  	      var self = this;
  
  	      self._drain();
  
  	      // Find the first inactive node to recycle.
  	      for (var i=0; i<self._sounds.length; i++) {
  	        if (self._sounds[i]._ended) {
  	          return self._sounds[i].reset();
  	        }
  	      }
  
  	      // If no inactive node was found, create a new one.
  	      return new Sound(self);
  	    },
  
  	    /**
  	     * Drain excess inactive sounds from the pool.
  	     */
  	    _drain: function() {
  	      var self = this;
  	      var limit = self._pool;
  	      var cnt = 0;
  	      var i = 0;
  
  	      // If there are less sounds than the max pool size, we are done.
  	      if (self._sounds.length < limit) {
  	        return;
  	      }
  
  	      // Count the number of inactive sounds.
  	      for (i=0; i<self._sounds.length; i++) {
  	        if (self._sounds[i]._ended) {
  	          cnt++;
  	        }
  	      }
  
  	      // Remove excess inactive sounds, going in reverse order.
  	      for (i=self._sounds.length - 1; i>=0; i--) {
  	        if (cnt <= limit) {
  	          return;
  	        }
  
  	        if (self._sounds[i]._ended) {
  	          // Disconnect the audio source when using Web Audio.
  	          if (self._webAudio && self._sounds[i]._node) {
  	            self._sounds[i]._node.disconnect(0);
  	          }
  
  	          // Remove sounds until we have the pool size.
  	          self._sounds.splice(i, 1);
  	          cnt--;
  	        }
  	      }
  	    },
  
  	    /**
  	     * Get all ID's from the sounds pool.
  	     * @param  {Number} id Only return one ID if one is passed.
  	     * @return {Array}    Array of IDs.
  	     */
  	    _getSoundIds: function(id) {
  	      var self = this;
  
  	      if (typeof id === 'undefined') {
  	        var ids = [];
  	        for (var i=0; i<self._sounds.length; i++) {
  	          ids.push(self._sounds[i]._id);
  	        }
  
  	        return ids;
  	      } else {
  	        return [id];
  	      }
  	    },
  
  	    /**
  	     * Load the sound back into the buffer source.
  	     * @param  {Sound} sound The sound object to work with.
  	     * @return {Howl}
  	     */
  	    _refreshBuffer: function(sound) {
  	      var self = this;
  
  	      // Setup the buffer source for playback.
  	      sound._node.bufferSource = Howler.ctx.createBufferSource();
  	      sound._node.bufferSource.buffer = cache[self._src];
  
  	      // Connect to the correct node.
  	      if (sound._panner) {
  	        sound._node.bufferSource.connect(sound._panner);
  	      } else {
  	        sound._node.bufferSource.connect(sound._node);
  	      }
  
  	      // Setup looping and playback rate.
  	      sound._node.bufferSource.loop = sound._loop;
  	      if (sound._loop) {
  	        sound._node.bufferSource.loopStart = sound._start || 0;
  	        sound._node.bufferSource.loopEnd = sound._stop || 0;
  	      }
  	      sound._node.bufferSource.playbackRate.setValueAtTime(sound._rate, Howler.ctx.currentTime);
  
  	      return self;
  	    },
  
  	    /**
  	     * Prevent memory leaks by cleaning up the buffer source after playback.
  	     * @param  {Object} node Sound's audio node containing the buffer source.
  	     * @return {Howl}
  	     */
  	    _cleanBuffer: function(node) {
  	      var self = this;
  	      var isIOS = Howler._navigator && Howler._navigator.vendor.indexOf('Apple') >= 0;
  
  	      if (Howler._scratchBuffer && node.bufferSource) {
  	        node.bufferSource.onended = null;
  	        node.bufferSource.disconnect(0);
  	        if (isIOS) {
  	          try { node.bufferSource.buffer = Howler._scratchBuffer; } catch(e) {}
  	        }
  	      }
  	      node.bufferSource = null;
  
  	      return self;
  	    },
  
  	    /**
  	     * Set the source to a 0-second silence to stop any downloading (except in IE).
  	     * @param  {Object} node Audio node to clear.
  	     */
  	    _clearSound: function(node) {
  	      var checkIE = /MSIE |Trident\//.test(Howler._navigator && Howler._navigator.userAgent);
  	      if (!checkIE) {
  	        node.src = 'data:audio/wav;base64,UklGRigAAABXQVZFZm10IBIAAAABAAEARKwAAIhYAQACABAAAABkYXRhAgAAAAEA';
  	      }
  	    }
  	  };
  
  	  /** Single Sound Methods **/
  	  /***************************************************************************/
  
  	  /**
  	   * Setup the sound object, which each node attached to a Howl group is contained in.
  	   * @param {Object} howl The Howl parent group.
  	   */
  	  var Sound = function(howl) {
  	    this._parent = howl;
  	    this.init();
  	  };
  	  Sound.prototype = {
  	    /**
  	     * Initialize a new Sound object.
  	     * @return {Sound}
  	     */
  	    init: function() {
  	      var self = this;
  	      var parent = self._parent;
  
  	      // Setup the default parameters.
  	      self._muted = parent._muted;
  	      self._loop = parent._loop;
  	      self._volume = parent._volume;
  	      self._rate = parent._rate;
  	      self._seek = 0;
  	      self._paused = true;
  	      self._ended = true;
  	      self._sprite = '__default';
  
  	      // Generate a unique ID for this sound.
  	      self._id = ++Howler._counter;
  
  	      // Add itself to the parent's pool.
  	      parent._sounds.push(self);
  
  	      // Create the new node.
  	      self.create();
  
  	      return self;
  	    },
  
  	    /**
  	     * Create and setup a new sound object, whether HTML5 Audio or Web Audio.
  	     * @return {Sound}
  	     */
  	    create: function() {
  	      var self = this;
  	      var parent = self._parent;
  	      var volume = (Howler._muted || self._muted || self._parent._muted) ? 0 : self._volume;
  
  	      if (parent._webAudio) {
  	        // Create the gain node for controlling volume (the source will connect to this).
  	        self._node = (typeof Howler.ctx.createGain === 'undefined') ? Howler.ctx.createGainNode() : Howler.ctx.createGain();
  	        self._node.gain.setValueAtTime(volume, Howler.ctx.currentTime);
  	        self._node.paused = true;
  	        self._node.connect(Howler.masterGain);
  	      } else {
  	        // Get an unlocked Audio object from the pool.
  	        self._node = Howler._obtainHtml5Audio();
  
  	        // Listen for errors (http://dev.w3.org/html5/spec-author-view/spec.html#mediaerror).
  	        self._errorFn = self._errorListener.bind(self);
  	        self._node.addEventListener('error', self._errorFn, false);
  
  	        // Listen for 'canplaythrough' event to let us know the sound is ready.
  	        self._loadFn = self._loadListener.bind(self);
  	        self._node.addEventListener(Howler._canPlayEvent, self._loadFn, false);
  
  	        // Setup the new audio node.
  	        self._node.src = parent._src;
  	        self._node.preload = 'auto';
  	        self._node.volume = volume * Howler.volume();
  
  	        // Begin loading the source.
  	        self._node.load();
  	      }
  
  	      return self;
  	    },
  
  	    /**
  	     * Reset the parameters of this sound to the original state (for recycle).
  	     * @return {Sound}
  	     */
  	    reset: function() {
  	      var self = this;
  	      var parent = self._parent;
  
  	      // Reset all of the parameters of this sound.
  	      self._muted = parent._muted;
  	      self._loop = parent._loop;
  	      self._volume = parent._volume;
  	      self._rate = parent._rate;
  	      self._seek = 0;
  	      self._rateSeek = 0;
  	      self._paused = true;
  	      self._ended = true;
  	      self._sprite = '__default';
  
  	      // Generate a new ID so that it isn't confused with the previous sound.
  	      self._id = ++Howler._counter;
  
  	      return self;
  	    },
  
  	    /**
  	     * HTML5 Audio error listener callback.
  	     */
  	    _errorListener: function() {
  	      var self = this;
  
  	      // Fire an error event and pass back the code.
  	      self._parent._emit('loaderror', self._id, self._node.error ? self._node.error.code : 0);
  
  	      // Clear the event listener.
  	      self._node.removeEventListener('error', self._errorFn, false);
  	    },
  
  	    /**
  	     * HTML5 Audio canplaythrough listener callback.
  	     */
  	    _loadListener: function() {
  	      var self = this;
  	      var parent = self._parent;
  
  	      // Round up the duration to account for the lower precision in HTML5 Audio.
  	      parent._duration = Math.ceil(self._node.duration * 10) / 10;
  
  	      // Setup a sprite if none is defined.
  	      if (Object.keys(parent._sprite).length === 0) {
  	        parent._sprite = {__default: [0, parent._duration * 1000]};
  	      }
  
  	      if (parent._state !== 'loaded') {
  	        parent._state = 'loaded';
  	        parent._emit('load');
  	        parent._loadQueue();
  	      }
  
  	      // Clear the event listener.
  	      self._node.removeEventListener(Howler._canPlayEvent, self._loadFn, false);
  	    }
  	  };
  
  	  /** Helper Methods **/
  	  /***************************************************************************/
  
  	  var cache = {};
  
  	  /**
  	   * Buffer a sound from URL, Data URI or cache and decode to audio source (Web Audio API).
  	   * @param  {Howl} self
  	   */
  	  var loadBuffer = function(self) {
  	    var url = self._src;
  
  	    // Check if the buffer has already been cached and use it instead.
  	    if (cache[url]) {
  	      // Set the duration from the cache.
  	      self._duration = cache[url].duration;
  
  	      // Load the sound into this Howl.
  	      loadSound(self);
  
  	      return;
  	    }
  
  	    if (/^data:[^;]+;base64,/.test(url)) {
  	      // Decode the base64 data URI without XHR, since some browsers don't support it.
  	      var data = atob(url.split(',')[1]);
  	      var dataView = new Uint8Array(data.length);
  	      for (var i=0; i<data.length; ++i) {
  	        dataView[i] = data.charCodeAt(i);
  	      }
  
  	      decodeAudioData(dataView.buffer, self);
  	    } else {
  	      // Load the buffer from the URL.
  	      var xhr = new XMLHttpRequest();
  	      xhr.open('GET', url, true);
  	      xhr.withCredentials = self._xhrWithCredentials;
  	      xhr.responseType = 'arraybuffer';
  	      xhr.onload = function() {
  	        // Make sure we get a successful response back.
  	        var code = (xhr.status + '')[0];
  	        if (code !== '0' && code !== '2' && code !== '3') {
  	          self._emit('loaderror', null, 'Failed loading audio file with status: ' + xhr.status + '.');
  	          return;
  	        }
  
  	        decodeAudioData(xhr.response, self);
  	      };
  	      xhr.onerror = function() {
  	        // If there is an error, switch to HTML5 Audio.
  	        if (self._webAudio) {
  	          self._html5 = true;
  	          self._webAudio = false;
  	          self._sounds = [];
  	          delete cache[url];
  	          self.load();
  	        }
  	      };
  	      safeXhrSend(xhr);
  	    }
  	  };
  
  	  /**
  	   * Send the XHR request wrapped in a try/catch.
  	   * @param  {Object} xhr XHR to send.
  	   */
  	  var safeXhrSend = function(xhr) {
  	    try {
  	      xhr.send();
  	    } catch (e) {
  	      xhr.onerror();
  	    }
  	  };
  
  	  /**
  	   * Decode audio data from an array buffer.
  	   * @param  {ArrayBuffer} arraybuffer The audio data.
  	   * @param  {Howl}        self
  	   */
  	  var decodeAudioData = function(arraybuffer, self) {
  	    // Fire a load error if something broke.
  	    var error = function() {
  	      self._emit('loaderror', null, 'Decoding audio data failed.');
  	    };
  
  	    // Load the sound on success.
  	    var success = function(buffer) {
  	      if (buffer && self._sounds.length > 0) {
  	        cache[self._src] = buffer;
  	        loadSound(self, buffer);
  	      } else {
  	        error();
  	      }
  	    };
  
  	    // Decode the buffer into an audio source.
  	    if (typeof Promise !== 'undefined' && Howler.ctx.decodeAudioData.length === 1) {
  	      Howler.ctx.decodeAudioData(arraybuffer).then(success).catch(error);
  	    } else {
  	      Howler.ctx.decodeAudioData(arraybuffer, success, error);
  	    }
  	  };
  
  	  /**
  	   * Sound is now loaded, so finish setting everything up and fire the loaded event.
  	   * @param  {Howl} self
  	   * @param  {Object} buffer The decoded buffer sound source.
  	   */
  	  var loadSound = function(self, buffer) {
  	    // Set the duration.
  	    if (buffer && !self._duration) {
  	      self._duration = buffer.duration;
  	    }
  
  	    // Setup a sprite if none is defined.
  	    if (Object.keys(self._sprite).length === 0) {
  	      self._sprite = {__default: [0, self._duration * 1000]};
  	    }
  
  	    // Fire the loaded event.
  	    if (self._state !== 'loaded') {
  	      self._state = 'loaded';
  	      self._emit('load');
  	      self._loadQueue();
  	    }
  	  };
  
  	  /**
  	   * Setup the audio context when available, or switch to HTML5 Audio mode.
  	   */
  	  var setupAudioContext = function() {
  	    // If we have already detected that Web Audio isn't supported, don't run this step again.
  	    if (!Howler.usingWebAudio) {
  	      return;
  	    }
  
  	    // Check if we are using Web Audio and setup the AudioContext if we are.
  	    try {
  	      if (typeof AudioContext !== 'undefined') {
  	        Howler.ctx = new AudioContext();
  	      } else if (typeof webkitAudioContext !== 'undefined') {
  	        Howler.ctx = new webkitAudioContext();
  	      } else {
  	        Howler.usingWebAudio = false;
  	      }
  	    } catch(e) {
  	      Howler.usingWebAudio = false;
  	    }
  
  	    // If the audio context creation still failed, set using web audio to false.
  	    if (!Howler.ctx) {
  	      Howler.usingWebAudio = false;
  	    }
  
  	    // Check if a webview is being used on iOS8 or earlier (rather than the browser).
  	    // If it is, disable Web Audio as it causes crashing.
  	    var iOS = (/iP(hone|od|ad)/.test(Howler._navigator && Howler._navigator.platform));
  	    var appVersion = Howler._navigator && Howler._navigator.appVersion.match(/OS (\d+)_(\d+)_?(\d+)?/);
  	    var version = appVersion ? parseInt(appVersion[1], 10) : null;
  	    if (iOS && version && version < 9) {
  	      var safari = /safari/.test(Howler._navigator && Howler._navigator.userAgent.toLowerCase());
  	      if (Howler._navigator && Howler._navigator.standalone && !safari || Howler._navigator && !Howler._navigator.standalone && !safari) {
  	        Howler.usingWebAudio = false;
  	      }
  	    }
  
  	    // Create and expose the master GainNode when using Web Audio (useful for plugins or advanced usage).
  	    if (Howler.usingWebAudio) {
  	      Howler.masterGain = (typeof Howler.ctx.createGain === 'undefined') ? Howler.ctx.createGainNode() : Howler.ctx.createGain();
  	      Howler.masterGain.gain.setValueAtTime(Howler._muted ? 0 : 1, Howler.ctx.currentTime);
  	      Howler.masterGain.connect(Howler.ctx.destination);
  	    }
  
  	    // Re-run the setup on Howler.
  	    Howler._setup();
  	  };
  
  	  // Add support for CommonJS libraries such as browserify.
  	  {
  	    exports.Howler = Howler;
  	    exports.Howl = Howl;
  	  }
  
  	  // Define globally in case AMD is not available or unused.
  	  if (typeof window !== 'undefined') {
  	    window.HowlerGlobal = HowlerGlobal;
  	    window.Howler = Howler;
  	    window.Howl = Howl;
  	    window.Sound = Sound;
  	  } else if (typeof commonjsGlobal !== 'undefined') { // Add to global in Node.js (for testing, etc).
  	    commonjsGlobal.HowlerGlobal = HowlerGlobal;
  	    commonjsGlobal.Howler = Howler;
  	    commonjsGlobal.Howl = Howl;
  	    commonjsGlobal.Sound = Sound;
  	  }
  	})();
  
  
  	/*!
  	 *  Spatial Plugin - Adds support for stereo and 3D audio where Web Audio is supported.
  	 *  
  	 *  howler.js v2.1.2
  	 *  howlerjs.com
  	 *
  	 *  (c) 2013-2019, James Simpson of GoldFire Studios
  	 *  goldfirestudios.com
  	 *
  	 *  MIT License
  	 */
  
  	(function() {
  
  	  // Setup default properties.
  	  HowlerGlobal.prototype._pos = [0, 0, 0];
  	  HowlerGlobal.prototype._orientation = [0, 0, -1, 0, 1, 0];
  
  	  /** Global Methods **/
  	  /***************************************************************************/
  
  	  /**
  	   * Helper method to update the stereo panning position of all current Howls.
  	   * Future Howls will not use this value unless explicitly set.
  	   * @param  {Number} pan A value of -1.0 is all the way left and 1.0 is all the way right.
  	   * @return {Howler/Number}     Self or current stereo panning value.
  	   */
  	  HowlerGlobal.prototype.stereo = function(pan) {
  	    var self = this;
  
  	    // Stop right here if not using Web Audio.
  	    if (!self.ctx || !self.ctx.listener) {
  	      return self;
  	    }
  
  	    // Loop through all Howls and update their stereo panning.
  	    for (var i=self._howls.length-1; i>=0; i--) {
  	      self._howls[i].stereo(pan);
  	    }
  
  	    return self;
  	  };
  
  	  /**
  	   * Get/set the position of the listener in 3D cartesian space. Sounds using
  	   * 3D position will be relative to the listener's position.
  	   * @param  {Number} x The x-position of the listener.
  	   * @param  {Number} y The y-position of the listener.
  	   * @param  {Number} z The z-position of the listener.
  	   * @return {Howler/Array}   Self or current listener position.
  	   */
  	  HowlerGlobal.prototype.pos = function(x, y, z) {
  	    var self = this;
  
  	    // Stop right here if not using Web Audio.
  	    if (!self.ctx || !self.ctx.listener) {
  	      return self;
  	    }
  
  	    // Set the defaults for optional 'y' & 'z'.
  	    y = (typeof y !== 'number') ? self._pos[1] : y;
  	    z = (typeof z !== 'number') ? self._pos[2] : z;
  
  	    if (typeof x === 'number') {
  	      self._pos = [x, y, z];
  
  	      if (typeof self.ctx.listener.positionX !== 'undefined') {
  	        self.ctx.listener.positionX.setTargetAtTime(self._pos[0], Howler.ctx.currentTime, 0.1);
  	        self.ctx.listener.positionY.setTargetAtTime(self._pos[1], Howler.ctx.currentTime, 0.1);
  	        self.ctx.listener.positionZ.setTargetAtTime(self._pos[2], Howler.ctx.currentTime, 0.1);
  	      } else {
  	        self.ctx.listener.setPosition(self._pos[0], self._pos[1], self._pos[2]);
  	      }
  	    } else {
  	      return self._pos;
  	    }
  
  	    return self;
  	  };
  
  	  /**
  	   * Get/set the direction the listener is pointing in the 3D cartesian space.
  	   * A front and up vector must be provided. The front is the direction the
  	   * face of the listener is pointing, and up is the direction the top of the
  	   * listener is pointing. Thus, these values are expected to be at right angles
  	   * from each other.
  	   * @param  {Number} x   The x-orientation of the listener.
  	   * @param  {Number} y   The y-orientation of the listener.
  	   * @param  {Number} z   The z-orientation of the listener.
  	   * @param  {Number} xUp The x-orientation of the top of the listener.
  	   * @param  {Number} yUp The y-orientation of the top of the listener.
  	   * @param  {Number} zUp The z-orientation of the top of the listener.
  	   * @return {Howler/Array}     Returns self or the current orientation vectors.
  	   */
  	  HowlerGlobal.prototype.orientation = function(x, y, z, xUp, yUp, zUp) {
  	    var self = this;
  
  	    // Stop right here if not using Web Audio.
  	    if (!self.ctx || !self.ctx.listener) {
  	      return self;
  	    }
  
  	    // Set the defaults for optional 'y' & 'z'.
  	    var or = self._orientation;
  	    y = (typeof y !== 'number') ? or[1] : y;
  	    z = (typeof z !== 'number') ? or[2] : z;
  	    xUp = (typeof xUp !== 'number') ? or[3] : xUp;
  	    yUp = (typeof yUp !== 'number') ? or[4] : yUp;
  	    zUp = (typeof zUp !== 'number') ? or[5] : zUp;
  
  	    if (typeof x === 'number') {
  	      self._orientation = [x, y, z, xUp, yUp, zUp];
  
  	      if (typeof self.ctx.listener.forwardX !== 'undefined') {
  	        self.ctx.listener.forwardX.setTargetAtTime(x, Howler.ctx.currentTime, 0.1);
  	        self.ctx.listener.forwardY.setTargetAtTime(y, Howler.ctx.currentTime, 0.1);
  	        self.ctx.listener.forwardZ.setTargetAtTime(z, Howler.ctx.currentTime, 0.1);
  	        self.ctx.listener.upX.setTargetAtTime(x, Howler.ctx.currentTime, 0.1);
  	        self.ctx.listener.upY.setTargetAtTime(y, Howler.ctx.currentTime, 0.1);
  	        self.ctx.listener.upZ.setTargetAtTime(z, Howler.ctx.currentTime, 0.1);
  	      } else {
  	        self.ctx.listener.setOrientation(x, y, z, xUp, yUp, zUp);
  	      }
  	    } else {
  	      return or;
  	    }
  
  	    return self;
  	  };
  
  	  /** Group Methods **/
  	  /***************************************************************************/
  
  	  /**
  	   * Add new properties to the core init.
  	   * @param  {Function} _super Core init method.
  	   * @return {Howl}
  	   */
  	  Howl.prototype.init = (function(_super) {
  	    return function(o) {
  	      var self = this;
  
  	      // Setup user-defined default properties.
  	      self._orientation = o.orientation || [1, 0, 0];
  	      self._stereo = o.stereo || null;
  	      self._pos = o.pos || null;
  	      self._pannerAttr = {
  	        coneInnerAngle: typeof o.coneInnerAngle !== 'undefined' ? o.coneInnerAngle : 360,
  	        coneOuterAngle: typeof o.coneOuterAngle !== 'undefined' ? o.coneOuterAngle : 360,
  	        coneOuterGain: typeof o.coneOuterGain !== 'undefined' ? o.coneOuterGain : 0,
  	        distanceModel: typeof o.distanceModel !== 'undefined' ? o.distanceModel : 'inverse',
  	        maxDistance: typeof o.maxDistance !== 'undefined' ? o.maxDistance : 10000,
  	        panningModel: typeof o.panningModel !== 'undefined' ? o.panningModel : 'HRTF',
  	        refDistance: typeof o.refDistance !== 'undefined' ? o.refDistance : 1,
  	        rolloffFactor: typeof o.rolloffFactor !== 'undefined' ? o.rolloffFactor : 1
  	      };
  
  	      // Setup event listeners.
  	      self._onstereo = o.onstereo ? [{fn: o.onstereo}] : [];
  	      self._onpos = o.onpos ? [{fn: o.onpos}] : [];
  	      self._onorientation = o.onorientation ? [{fn: o.onorientation}] : [];
  
  	      // Complete initilization with howler.js core's init function.
  	      return _super.call(this, o);
  	    };
  	  })(Howl.prototype.init);
  
  	  /**
  	   * Get/set the stereo panning of the audio source for this sound or all in the group.
  	   * @param  {Number} pan  A value of -1.0 is all the way left and 1.0 is all the way right.
  	   * @param  {Number} id (optional) The sound ID. If none is passed, all in group will be updated.
  	   * @return {Howl/Number}    Returns self or the current stereo panning value.
  	   */
  	  Howl.prototype.stereo = function(pan, id) {
  	    var self = this;
  
  	    // Stop right here if not using Web Audio.
  	    if (!self._webAudio) {
  	      return self;
  	    }
  
  	    // If the sound hasn't loaded, add it to the load queue to change stereo pan when capable.
  	    if (self._state !== 'loaded') {
  	      self._queue.push({
  	        event: 'stereo',
  	        action: function() {
  	          self.stereo(pan, id);
  	        }
  	      });
  
  	      return self;
  	    }
  
  	    // Check for PannerStereoNode support and fallback to PannerNode if it doesn't exist.
  	    var pannerType = (typeof Howler.ctx.createStereoPanner === 'undefined') ? 'spatial' : 'stereo';
  
  	    // Setup the group's stereo panning if no ID is passed.
  	    if (typeof id === 'undefined') {
  	      // Return the group's stereo panning if no parameters are passed.
  	      if (typeof pan === 'number') {
  	        self._stereo = pan;
  	        self._pos = [pan, 0, 0];
  	      } else {
  	        return self._stereo;
  	      }
  	    }
  
  	    // Change the streo panning of one or all sounds in group.
  	    var ids = self._getSoundIds(id);
  	    for (var i=0; i<ids.length; i++) {
  	      // Get the sound.
  	      var sound = self._soundById(ids[i]);
  
  	      if (sound) {
  	        if (typeof pan === 'number') {
  	          sound._stereo = pan;
  	          sound._pos = [pan, 0, 0];
  
  	          if (sound._node) {
  	            // If we are falling back, make sure the panningModel is equalpower.
  	            sound._pannerAttr.panningModel = 'equalpower';
  
  	            // Check if there is a panner setup and create a new one if not.
  	            if (!sound._panner || !sound._panner.pan) {
  	              setupPanner(sound, pannerType);
  	            }
  
  	            if (pannerType === 'spatial') {
  	              if (typeof sound._panner.positionX !== 'undefined') {
  	                sound._panner.positionX.setValueAtTime(pan, Howler.ctx.currentTime);
  	                sound._panner.positionY.setValueAtTime(0, Howler.ctx.currentTime);
  	                sound._panner.positionZ.setValueAtTime(0, Howler.ctx.currentTime);
  	              } else {
  	                sound._panner.setPosition(pan, 0, 0);
  	              }
  	            } else {
  	              sound._panner.pan.setValueAtTime(pan, Howler.ctx.currentTime);
  	            }
  	          }
  
  	          self._emit('stereo', sound._id);
  	        } else {
  	          return sound._stereo;
  	        }
  	      }
  	    }
  
  	    return self;
  	  };
  
  	  /**
  	   * Get/set the 3D spatial position of the audio source for this sound or group relative to the global listener.
  	   * @param  {Number} x  The x-position of the audio source.
  	   * @param  {Number} y  The y-position of the audio source.
  	   * @param  {Number} z  The z-position of the audio source.
  	   * @param  {Number} id (optional) The sound ID. If none is passed, all in group will be updated.
  	   * @return {Howl/Array}    Returns self or the current 3D spatial position: [x, y, z].
  	   */
  	  Howl.prototype.pos = function(x, y, z, id) {
  	    var self = this;
  
  	    // Stop right here if not using Web Audio.
  	    if (!self._webAudio) {
  	      return self;
  	    }
  
  	    // If the sound hasn't loaded, add it to the load queue to change position when capable.
  	    if (self._state !== 'loaded') {
  	      self._queue.push({
  	        event: 'pos',
  	        action: function() {
  	          self.pos(x, y, z, id);
  	        }
  	      });
  
  	      return self;
  	    }
  
  	    // Set the defaults for optional 'y' & 'z'.
  	    y = (typeof y !== 'number') ? 0 : y;
  	    z = (typeof z !== 'number') ? -0.5 : z;
  
  	    // Setup the group's spatial position if no ID is passed.
  	    if (typeof id === 'undefined') {
  	      // Return the group's spatial position if no parameters are passed.
  	      if (typeof x === 'number') {
  	        self._pos = [x, y, z];
  	      } else {
  	        return self._pos;
  	      }
  	    }
  
  	    // Change the spatial position of one or all sounds in group.
  	    var ids = self._getSoundIds(id);
  	    for (var i=0; i<ids.length; i++) {
  	      // Get the sound.
  	      var sound = self._soundById(ids[i]);
  
  	      if (sound) {
  	        if (typeof x === 'number') {
  	          sound._pos = [x, y, z];
  
  	          if (sound._node) {
  	            // Check if there is a panner setup and create a new one if not.
  	            if (!sound._panner || sound._panner.pan) {
  	              setupPanner(sound, 'spatial');
  	            }
  
  	            if (typeof sound._panner.positionX !== 'undefined') {
  	              sound._panner.positionX.setValueAtTime(x, Howler.ctx.currentTime);
  	              sound._panner.positionY.setValueAtTime(y, Howler.ctx.currentTime);
  	              sound._panner.positionZ.setValueAtTime(z, Howler.ctx.currentTime);
  	            } else {
  	              sound._panner.setPosition(x, y, z);
  	            }
  	          }
  
  	          self._emit('pos', sound._id);
  	        } else {
  	          return sound._pos;
  	        }
  	      }
  	    }
  
  	    return self;
  	  };
  
  	  /**
  	   * Get/set the direction the audio source is pointing in the 3D cartesian coordinate
  	   * space. Depending on how direction the sound is, based on the `cone` attributes,
  	   * a sound pointing away from the listener can be quiet or silent.
  	   * @param  {Number} x  The x-orientation of the source.
  	   * @param  {Number} y  The y-orientation of the source.
  	   * @param  {Number} z  The z-orientation of the source.
  	   * @param  {Number} id (optional) The sound ID. If none is passed, all in group will be updated.
  	   * @return {Howl/Array}    Returns self or the current 3D spatial orientation: [x, y, z].
  	   */
  	  Howl.prototype.orientation = function(x, y, z, id) {
  	    var self = this;
  
  	    // Stop right here if not using Web Audio.
  	    if (!self._webAudio) {
  	      return self;
  	    }
  
  	    // If the sound hasn't loaded, add it to the load queue to change orientation when capable.
  	    if (self._state !== 'loaded') {
  	      self._queue.push({
  	        event: 'orientation',
  	        action: function() {
  	          self.orientation(x, y, z, id);
  	        }
  	      });
  
  	      return self;
  	    }
  
  	    // Set the defaults for optional 'y' & 'z'.
  	    y = (typeof y !== 'number') ? self._orientation[1] : y;
  	    z = (typeof z !== 'number') ? self._orientation[2] : z;
  
  	    // Setup the group's spatial orientation if no ID is passed.
  	    if (typeof id === 'undefined') {
  	      // Return the group's spatial orientation if no parameters are passed.
  	      if (typeof x === 'number') {
  	        self._orientation = [x, y, z];
  	      } else {
  	        return self._orientation;
  	      }
  	    }
  
  	    // Change the spatial orientation of one or all sounds in group.
  	    var ids = self._getSoundIds(id);
  	    for (var i=0; i<ids.length; i++) {
  	      // Get the sound.
  	      var sound = self._soundById(ids[i]);
  
  	      if (sound) {
  	        if (typeof x === 'number') {
  	          sound._orientation = [x, y, z];
  
  	          if (sound._node) {
  	            // Check if there is a panner setup and create a new one if not.
  	            if (!sound._panner) {
  	              // Make sure we have a position to setup the node with.
  	              if (!sound._pos) {
  	                sound._pos = self._pos || [0, 0, -0.5];
  	              }
  
  	              setupPanner(sound, 'spatial');
  	            }
  
  	            if (typeof sound._panner.orientationX !== 'undefined') {
  	              sound._panner.orientationX.setValueAtTime(x, Howler.ctx.currentTime);
  	              sound._panner.orientationY.setValueAtTime(y, Howler.ctx.currentTime);
  	              sound._panner.orientationZ.setValueAtTime(z, Howler.ctx.currentTime);
  	            } else {
  	              sound._panner.setOrientation(x, y, z);
  	            }
  	          }
  
  	          self._emit('orientation', sound._id);
  	        } else {
  	          return sound._orientation;
  	        }
  	      }
  	    }
  
  	    return self;
  	  };
  
  	  /**
  	   * Get/set the panner node's attributes for a sound or group of sounds.
  	   * This method can optionall take 0, 1 or 2 arguments.
  	   *   pannerAttr() -> Returns the group's values.
  	   *   pannerAttr(id) -> Returns the sound id's values.
  	   *   pannerAttr(o) -> Set's the values of all sounds in this Howl group.
  	   *   pannerAttr(o, id) -> Set's the values of passed sound id.
  	   *
  	   *   Attributes:
  	   *     coneInnerAngle - (360 by default) A parameter for directional audio sources, this is an angle, in degrees,
  	   *                      inside of which there will be no volume reduction.
  	   *     coneOuterAngle - (360 by default) A parameter for directional audio sources, this is an angle, in degrees,
  	   *                      outside of which the volume will be reduced to a constant value of `coneOuterGain`.
  	   *     coneOuterGain - (0 by default) A parameter for directional audio sources, this is the gain outside of the
  	   *                     `coneOuterAngle`. It is a linear value in the range `[0, 1]`.
  	   *     distanceModel - ('inverse' by default) Determines algorithm used to reduce volume as audio moves away from
  	   *                     listener. Can be `linear`, `inverse` or `exponential.
  	   *     maxDistance - (10000 by default) The maximum distance between source and listener, after which the volume
  	   *                   will not be reduced any further.
  	   *     refDistance - (1 by default) A reference distance for reducing volume as source moves further from the listener.
  	   *                   This is simply a variable of the distance model and has a different effect depending on which model
  	   *                   is used and the scale of your coordinates. Generally, volume will be equal to 1 at this distance.
  	   *     rolloffFactor - (1 by default) How quickly the volume reduces as source moves from listener. This is simply a
  	   *                     variable of the distance model and can be in the range of `[0, 1]` with `linear` and `[0, ∞]`
  	   *                     with `inverse` and `exponential`.
  	   *     panningModel - ('HRTF' by default) Determines which spatialization algorithm is used to position audio.
  	   *                     Can be `HRTF` or `equalpower`.
  	   *
  	   * @return {Howl/Object} Returns self or current panner attributes.
  	   */
  	  Howl.prototype.pannerAttr = function() {
  	    var self = this;
  	    var args = arguments;
  	    var o, id, sound;
  
  	    // Stop right here if not using Web Audio.
  	    if (!self._webAudio) {
  	      return self;
  	    }
  
  	    // Determine the values based on arguments.
  	    if (args.length === 0) {
  	      // Return the group's panner attribute values.
  	      return self._pannerAttr;
  	    } else if (args.length === 1) {
  	      if (typeof args[0] === 'object') {
  	        o = args[0];
  
  	        // Set the grou's panner attribute values.
  	        if (typeof id === 'undefined') {
  	          if (!o.pannerAttr) {
  	            o.pannerAttr = {
  	              coneInnerAngle: o.coneInnerAngle,
  	              coneOuterAngle: o.coneOuterAngle,
  	              coneOuterGain: o.coneOuterGain,
  	              distanceModel: o.distanceModel,
  	              maxDistance: o.maxDistance,
  	              refDistance: o.refDistance,
  	              rolloffFactor: o.rolloffFactor,
  	              panningModel: o.panningModel
  	            };
  	          }
  
  	          self._pannerAttr = {
  	            coneInnerAngle: typeof o.pannerAttr.coneInnerAngle !== 'undefined' ? o.pannerAttr.coneInnerAngle : self._coneInnerAngle,
  	            coneOuterAngle: typeof o.pannerAttr.coneOuterAngle !== 'undefined' ? o.pannerAttr.coneOuterAngle : self._coneOuterAngle,
  	            coneOuterGain: typeof o.pannerAttr.coneOuterGain !== 'undefined' ? o.pannerAttr.coneOuterGain : self._coneOuterGain,
  	            distanceModel: typeof o.pannerAttr.distanceModel !== 'undefined' ? o.pannerAttr.distanceModel : self._distanceModel,
  	            maxDistance: typeof o.pannerAttr.maxDistance !== 'undefined' ? o.pannerAttr.maxDistance : self._maxDistance,
  	            refDistance: typeof o.pannerAttr.refDistance !== 'undefined' ? o.pannerAttr.refDistance : self._refDistance,
  	            rolloffFactor: typeof o.pannerAttr.rolloffFactor !== 'undefined' ? o.pannerAttr.rolloffFactor : self._rolloffFactor,
  	            panningModel: typeof o.pannerAttr.panningModel !== 'undefined' ? o.pannerAttr.panningModel : self._panningModel
  	          };
  	        }
  	      } else {
  	        // Return this sound's panner attribute values.
  	        sound = self._soundById(parseInt(args[0], 10));
  	        return sound ? sound._pannerAttr : self._pannerAttr;
  	      }
  	    } else if (args.length === 2) {
  	      o = args[0];
  	      id = parseInt(args[1], 10);
  	    }
  
  	    // Update the values of the specified sounds.
  	    var ids = self._getSoundIds(id);
  	    for (var i=0; i<ids.length; i++) {
  	      sound = self._soundById(ids[i]);
  
  	      if (sound) {
  	        // Merge the new values into the sound.
  	        var pa = sound._pannerAttr;
  	        pa = {
  	          coneInnerAngle: typeof o.coneInnerAngle !== 'undefined' ? o.coneInnerAngle : pa.coneInnerAngle,
  	          coneOuterAngle: typeof o.coneOuterAngle !== 'undefined' ? o.coneOuterAngle : pa.coneOuterAngle,
  	          coneOuterGain: typeof o.coneOuterGain !== 'undefined' ? o.coneOuterGain : pa.coneOuterGain,
  	          distanceModel: typeof o.distanceModel !== 'undefined' ? o.distanceModel : pa.distanceModel,
  	          maxDistance: typeof o.maxDistance !== 'undefined' ? o.maxDistance : pa.maxDistance,
  	          refDistance: typeof o.refDistance !== 'undefined' ? o.refDistance : pa.refDistance,
  	          rolloffFactor: typeof o.rolloffFactor !== 'undefined' ? o.rolloffFactor : pa.rolloffFactor,
  	          panningModel: typeof o.panningModel !== 'undefined' ? o.panningModel : pa.panningModel
  	        };
  
  	        // Update the panner values or create a new panner if none exists.
  	        var panner = sound._panner;
  	        if (panner) {
  	          panner.coneInnerAngle = pa.coneInnerAngle;
  	          panner.coneOuterAngle = pa.coneOuterAngle;
  	          panner.coneOuterGain = pa.coneOuterGain;
  	          panner.distanceModel = pa.distanceModel;
  	          panner.maxDistance = pa.maxDistance;
  	          panner.refDistance = pa.refDistance;
  	          panner.rolloffFactor = pa.rolloffFactor;
  	          panner.panningModel = pa.panningModel;
  	        } else {
  	          // Make sure we have a position to setup the node with.
  	          if (!sound._pos) {
  	            sound._pos = self._pos || [0, 0, -0.5];
  	          }
  
  	          // Create a new panner node.
  	          setupPanner(sound, 'spatial');
  	        }
  	      }
  	    }
  
  	    return self;
  	  };
  
  	  /** Single Sound Methods **/
  	  /***************************************************************************/
  
  	  /**
  	   * Add new properties to the core Sound init.
  	   * @param  {Function} _super Core Sound init method.
  	   * @return {Sound}
  	   */
  	  Sound.prototype.init = (function(_super) {
  	    return function() {
  	      var self = this;
  	      var parent = self._parent;
  
  	      // Setup user-defined default properties.
  	      self._orientation = parent._orientation;
  	      self._stereo = parent._stereo;
  	      self._pos = parent._pos;
  	      self._pannerAttr = parent._pannerAttr;
  
  	      // Complete initilization with howler.js core Sound's init function.
  	      _super.call(this);
  
  	      // If a stereo or position was specified, set it up.
  	      if (self._stereo) {
  	        parent.stereo(self._stereo);
  	      } else if (self._pos) {
  	        parent.pos(self._pos[0], self._pos[1], self._pos[2], self._id);
  	      }
  	    };
  	  })(Sound.prototype.init);
  
  	  /**
  	   * Override the Sound.reset method to clean up properties from the spatial plugin.
  	   * @param  {Function} _super Sound reset method.
  	   * @return {Sound}
  	   */
  	  Sound.prototype.reset = (function(_super) {
  	    return function() {
  	      var self = this;
  	      var parent = self._parent;
  
  	      // Reset all spatial plugin properties on this sound.
  	      self._orientation = parent._orientation;
  	      self._stereo = parent._stereo;
  	      self._pos = parent._pos;
  	      self._pannerAttr = parent._pannerAttr;
  
  	      // If a stereo or position was specified, set it up.
  	      if (self._stereo) {
  	        parent.stereo(self._stereo);
  	      } else if (self._pos) {
  	        parent.pos(self._pos[0], self._pos[1], self._pos[2], self._id);
  	      } else if (self._panner) {
  	        // Disconnect the panner.
  	        self._panner.disconnect(0);
  	        self._panner = undefined;
  	        parent._refreshBuffer(self);
  	      }
  
  	      // Complete resetting of the sound.
  	      return _super.call(this);
  	    };
  	  })(Sound.prototype.reset);
  
  	  /** Helper Methods **/
  	  /***************************************************************************/
  
  	  /**
  	   * Create a new panner node and save it on the sound.
  	   * @param  {Sound} sound Specific sound to setup panning on.
  	   * @param {String} type Type of panner to create: 'stereo' or 'spatial'.
  	   */
  	  var setupPanner = function(sound, type) {
  	    type = type || 'spatial';
  
  	    // Create the new panner node.
  	    if (type === 'spatial') {
  	      sound._panner = Howler.ctx.createPanner();
  	      sound._panner.coneInnerAngle = sound._pannerAttr.coneInnerAngle;
  	      sound._panner.coneOuterAngle = sound._pannerAttr.coneOuterAngle;
  	      sound._panner.coneOuterGain = sound._pannerAttr.coneOuterGain;
  	      sound._panner.distanceModel = sound._pannerAttr.distanceModel;
  	      sound._panner.maxDistance = sound._pannerAttr.maxDistance;
  	      sound._panner.refDistance = sound._pannerAttr.refDistance;
  	      sound._panner.rolloffFactor = sound._pannerAttr.rolloffFactor;
  	      sound._panner.panningModel = sound._pannerAttr.panningModel;
  
  	      if (typeof sound._panner.positionX !== 'undefined') {
  	        sound._panner.positionX.setValueAtTime(sound._pos[0], Howler.ctx.currentTime);
  	        sound._panner.positionY.setValueAtTime(sound._pos[1], Howler.ctx.currentTime);
  	        sound._panner.positionZ.setValueAtTime(sound._pos[2], Howler.ctx.currentTime);
  	      } else {
  	        sound._panner.setPosition(sound._pos[0], sound._pos[1], sound._pos[2]);
  	      }
  
  	      if (typeof sound._panner.orientationX !== 'undefined') {
  	        sound._panner.orientationX.setValueAtTime(sound._orientation[0], Howler.ctx.currentTime);
  	        sound._panner.orientationY.setValueAtTime(sound._orientation[1], Howler.ctx.currentTime);
  	        sound._panner.orientationZ.setValueAtTime(sound._orientation[2], Howler.ctx.currentTime);
  	      } else {
  	        sound._panner.setOrientation(sound._orientation[0], sound._orientation[1], sound._orientation[2]);
  	      }
  	    } else {
  	      sound._panner = Howler.ctx.createStereoPanner();
  	      sound._panner.pan.setValueAtTime(sound._stereo, Howler.ctx.currentTime);
  	    }
  
  	    sound._panner.connect(sound._node);
  
  	    // Update the connections.
  	    if (!sound._paused) {
  	      sound._parent.pause(sound._id, true).play(sound._id, true);
  	    }
  	  };
  	})();
  	});
  	var howler_1 = howler.Howler;
  	var howler_2 = howler.Howl;
  
  	var Audio$1 =
  	/*#__PURE__*/
  	function () {
  	  function Audio() {
  	    classCallCheck(this, Audio);
  	  }
  
  	  createClass(Audio, [{
  	    key: "load",
  	    value: function load(url) {
  	      return new Promise(function (resolve, reject) {
  	        var audio = new howler_2({
  	          src: url,
  	          loop: false,
  	          autoplay: false
  	        });
  	        audio.once('load', function () {
  	          audio.key = url;
  	          resolve(audio);
  	        });
  	      });
  	    }
  	  }, {
  	    key: "mute",
  	    value: function mute(_mute) {
  	      return howler_1.mute(_mute);
  	    }
  	  }, {
  	    key: "volume",
  	    value: function volume(v) {
  	      return howler_1.volume(v);
  	    }
  	  }]);
  
  	  return Audio;
  	}();
  
  	function GetMainCanvasOffset(canvas, realWidth, realHeight) {
  	  var offsetWidth = realWidth;
  	  var offsetLeft = 0;
  	  var offsetHeight = realHeight;
  	  var offsetTop = 0;
  	  var ratio = realWidth / realHeight;
  
  	  if (ratio < 0.4) {
  	    offsetHeight = realWidth / 750 * 1334;
  	    offsetTop = (realHeight - offsetHeight) / 2;
  	    ratio = 750 / 1334;
  	  } else if (ratio > 0.8) {
  	    offsetWidth = realHeight / 1334 * 750;
  	    offsetLeft = (realWidth - offsetWidth) / 2;
  	    ratio = 750 / 1334;
  	  }
  
  	  canvas.style.position = 'absolute';
  	  canvas.style.top = offsetTop + 'px';
  	  canvas.style.left = offsetLeft + 'px';
  	  canvas.style.width = offsetWidth + 'px';
  	  canvas.style.height = offsetHeight + 'px';
  	  return {
  	    x: offsetLeft,
  	    y: offsetTop,
  	    width: offsetWidth,
  	    height: offsetHeight,
  	    ratio: ratio
  	  };
  	}
  
  	exports.Audio = Audio$1;
  	exports.Canvas = Canvas;
  	exports.Font = loadFont;
  	exports.GetMainCanvasOffset = GetMainCanvasOffset;
  	exports.Image = Image;
  	exports.System = System;
  	exports.Touch = TouchListen;
  
  	Object.defineProperty(exports, '__esModule', { value: true });
  
  })));
  