platform/video.videojs/dist/video.es.js
function getSelectedOptionValue(el, parser) {
  var value = el.options[el.options.selectedIndex].value;

  return parseOptionValue(value, parser);
}
function getSelectedOptionValue(el, parser) {
  var value = el.options[el.options.selectedIndex].value;

  return parseOptionValue(value, parser);
}
Gets the value of the selected <option> element within a <select> element.

@param  {Element} el
the element to look in

@param  {Function} [parser]
Optional function to adjust the value.

@return {Mixed}
- Will be `undefined` if no value exists
- Will be `undefined` if the given value is "none".
- Will be the actual value otherwise.

@private