视频文件使用的是MDN的例子的视频，所以不会存在ffmep4问题
后端通过node createReadStream读取视频文件流，通过pipe输出响应。
前端vue框架，主要参考了[MDN的例子]，(https://developer.mozilla.org...
拿到后端返回之后转为arraybuffer类型

getvideosource () {
      let cid = this.$route.query.chapterId
      let path = 'http://localhost:3000/api/chapter/learning/video'
      let mimeCodec = 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"'
      // let video = this.$refs.v1
      let video = document.getElementById('v1')
      let mediaSource
      let that = this
      if('MediaSource' in window && MediaSource.isTypeSupported(mimeCodec)) {
        console.log('MediaSource')
        mediaSource = new MediaSource()
        video.src = URL.createObjectURL(mediaSource)
        mediaSource.addEventListener('sourceopen',sourceOpen.bind(this))
      } else{
        console.error('Unsupported MIME type or codec:',mimeCodec)   
      }
      function sourceOpen () {
        console.log('has opened')
        URL.revokeObjectURL(video.src)
        let sourceBuffer = mediaSource.addSourceBuffer(mimeCodec)
        fetchAB(path,sourceBuffer)
      }
      function fetchAB (url,sourceBuffer) {
        axios.get(url).then((result)=>{
          console.log(Object.prototype.toString.call(result.data));
          // console.log(result.data);
          // let data = new Blob([result.data],{type: 'application/octet-stream'})
          // console.log(Object.prototype.toString.call(data));
          // console.log(data);
          // var reader = new FileReader();
          // reader.onload = function() {
          //   console.log(this.result);
          // }
          // reader.readAsArrayBuffer(blob);
          function toArrayBuffer(buf) {
            var ab = new ArrayBuffer(buf.length);
            var view = new Uint8Array(ab);
            for (var i = 0; i < buf.length; ++i) {
                view[i] = buf[i];
            }
            return ab;
          }
          let r = toArrayBuffer(result.data)
          console.log(Object.prototype.toString.call(r))
          sourceBuffer.addEventListener('updateend', function () {
            console.log(mediaSource.readyState);
            console.log(sourceBuffer)
            console.log(mediaSource);
            mediaSource.endOfStream()
          })
          sourceBuffer.appendBuffer(r)
        })
      }
    },

以上是全部的代码。
这个函数在mounted内调用
浏览器运行会在mediaSource.endOfStream()处报错

Failed to execute 'endOfStream' on 'MediaSource': The MediaSource's readyState is not 'open'.
有大佬知道这是怎么回事吗？？？