如何在ios safari上获取hls中的programDateTime？

<video id="videoPlayer" controls></video>

var video = document.getElementById('videoPlayer');
video.addEventListener('loadedmetadata', function() {
  var masterPlaylist = video.src;
  var xhr = new XMLHttpRequest();
  xhr.open('GET', masterPlaylist);
  xhr.onreadystatechange = function() {
    if (xhr.readyState === 4 && xhr.status === 200) {
      var playlistURL = parsePlaylistURL(xhr.responseText);
      getProgramDateTime(playlistURL);
    }
  };
  xhr.send();
});

function getProgramDateTime(playlistURL) {
  var xhr = new XMLHttpRequest();
  xhr.open('GET', playlistURL);
  xhr.onreadystatechange = function() {
    if (xhr.readyState === 4 && xhr.status === 200) {
      var tsURL = parseTSURL(xhr.responseText);
      getTSContent(tsURL);
    }
  };
  xhr.send();
}

function getTSContent(tsURL) {
  var xhr = new XMLHttpRequest();
  xhr.open('GET', tsURL);
  xhr.onreadystatechange = function() {
    if (xhr.readyState === 4 && xhr.status === 200) {
      var programDateTime = parseProgramDateTime(xhr.responseText);
      console.log('programDateTime:', programDateTime);
    }
  };
  xhr.send();
}

function parsePlaylistURL(playlistContent) {
  // 解析主播放列表的内容，获取第一个媒体播放列表的URL
  // 返回媒体播放列表的URL
}

function parseTSURL(playlistContent) {
  // 解析媒体播放列表的内容，获取第一个TS文件的URL
  // 返回TS文件的URL
}

function parseProgramDateTime(tsContent) {
  // 解析TS文件的内容，获取programDateTime标签的值
  // 返回programDateTime的值
}