js是如何实现带进度条的多视频上传？

 <link rel="stylesheet" href="bootstrap.css" rel="external nofollow" >
 <script src="jquery.fileupload.js"></script>
 <script src="http://malsup.github.com/jquery.form.js"></script>

<p class="form-group">
      <label>产品视频：</label>
      <p class="videoUpfile">
        <input type="file" name="avatarVideo" class="avatarVideo"><a class="btn deleteAvatarVideo" href="javascript:;" rel="external nofollow" rel="external nofollow" >删除</a>
        <p class="videoMaterials">
          <p class="progress">
            <p class="progress-bar progress-bar-success progress-bar-striped" role="progressbar" aria-valuenow="45" aria-valuemin="0" aria-valuemax="100" style="width: 0%">
              <span class="sr-only">0% Complete</span>
            </p>
          </p>
          <p class="files"></p>
          <p class="showimg"></p>
          <input type="hidden" value="" name="video_id[]">
          <p style="color: #b92c28" class="img_upload_info"></p>
        </p>
      </p>
      <p class="videoUpfile">
        <input type="file" name="avatarVideo" class="avatarVideo"><a class="btn deleteAvatarVideo" href="javascript:;" rel="external nofollow" rel="external nofollow" >删除</a>
        <p class="videoMaterials">
          <p class="progress">
            <p class="progress-bar progress-bar-success progress-bar-striped" role="progressbar" aria-valuenow="45" aria-valuemin="0" aria-valuemax="100" style="width: 0%">
              <span class="sr-only">0% Complete</span>
            </p>
          </p>
          <p class="files"></p>
          <p class="showimg"></p>
          <input type="hidden" value="" name="video_id[]">
          <p style="color: #b92c28" class="img_upload_info"></p>
        </p>
      </p>
</p>

//上传视频

$(".avatarVideo").change(function() {
  var _this = $(this);
  _this.wrap("<form class='fileUploadeVideo' action='/admin/uploadimg/addVideo' method='post' enctype='multipart/form-data'></form>");
  _this.parents('.fileUploadeVideo').ajaxSubmit({
    dataType: 'json',
    beforeSend: function () {
      $(".progress").show();
    },
    uploadProgress: function (event, position, total, percentComplete) {
      var percentVal = percentComplete + '%';
      _this.parents('.videoUpfile').find(".progress-bar").width(percentComplete + '%');
      _this.parents('.videoUpfile').find(".progress-bar").html(percentVal);
      _this.parents('.videoUpfile').find(".sr-only").html(percentComplete + '%');
    },
    success: function (data) {
      if(data.code==100) {
        _this.parents('.videoUpfile').find(".files").html("文件名: " + data.video_title);
        _this.parents('.videoUpfile').find("input[type=hidden]").val(data.video_id);
        alert("上传成功!");
      }else{
        alert("上传失败");
      }
    },
    error: function () {
      alert("上传失败");
    }
  });