如何在HTML5播放器中获得视频质量控制

<video id="myVideo" controls>
  <source src="video.mp4" type="video/mp4">
</video>

var video = document.getElementById("myVideo");
video.addEventListener("loadedmetadata", function() {
  // 在视频加载完成后执行以下操作
  // 获取视频的可用质量选项
  var availableQualities = video.getVideoPlaybackQuality().availableQualityLevels;
  // 打印可用质量选项
  console.log(availableQualities);
});

function changeVideoQuality(quality) {
  video.setVideoPlaybackQuality(quality);
}