platform/video.videojs/dist/video.es.js
function off(elem, type, fn) {
  // Don't want to add a cache object through getElData if not needed
  if (!hasData(elem)) {
    return;
  }

  var data = getData(elem);

  // If no events exist, nothing to unbind
  if (!data.handlers) {
    return;
  }

  if (Array.isArray(type)) {
    return _handleMultipleEvents(off, elem, type, fn);
  }

  // Utility function
  var removeType = function removeType(t) {
    data.handlers[t] = [];
    _cleanUpEvents(elem, t);
  };

  // Are we removing all bound events?
  if (!type) {
    for (var t in data.handlers) {
      removeType(t);
    }
    return;
  }

  var handlers = data.handlers[type];

  // If no handlers exist, nothing to unbind
  if (!handlers) {
    return;
  }

  // If no listener was provided, remove all listeners for type
  if (!fn) {
    removeType(type);
    return;
  }

  // We're only removing a single handler
  if (fn.guid) {
    for (var n = 0; n < handlers.length; n++) {
      if (handlers[n].guid === fn.guid) {
        handlers.splice(n--, 1);
      }
    }
  }

  _cleanUpEvents(elem, type);
}
function off(elem, type, fn) {
  // Don't want to add a cache object through getElData if not needed
  if (!hasData(elem)) {
    return;
  }

  var data = getData(elem);

  // If no events exist, nothing to unbind
  if (!data.handlers) {
    return;
  }

  if (Array.isArray(type)) {
    return _handleMultipleEvents(off, elem, type, fn);
  }

  // Utility function
  var removeType = function removeType(t) {
    data.handlers[t] = [];
    _cleanUpEvents(elem, t);
  };

  // Are we removing all bound events?
  if (!type) {
    for (var t in data.handlers) {
      removeType(t);
    }
    return;
  }

  var handlers = data.handlers[type];

  // If no handlers exist, nothing to unbind
  if (!handlers) {
    return;
  }

  // If no listener was provided, remove all listeners for type
  if (!fn) {
    removeType(type);
    return;
  }

  // We're only removing a single handler
  if (fn.guid) {
    for (var n = 0; n < handlers.length; n++) {
      if (handlers[n].guid === fn.guid) {
        handlers.splice(n--, 1);
      }
    }
  }

  _cleanUpEvents(elem, type);
}
Removes event listeners from an element

@param {Element|Object} elem
Object to remove listeners from.

@param {string|string[]} [type]
Type of listener to remove. Don't include to remove all events from element.

@param {EventTarget~EventListener} [fn]
Specific listener to remove. Don't include to remove listeners for an event
type.