Html5 video 上传预览图片视频，设置、预览视频某秒的海报帧

 /*预览*/              $(&#39;.qtuploader__items&#39;).on(&#39;click&#39;, &#39;[name="viewVideoPicBtn"]&#39;, function() {    var parent = $(this).closest(&#39;.qtab__page&#39;);    var video = $(this).closest(&#39;.qtuploader__itemsbd&#39;).find(&#39;video&#39;);    var srcStr = &#39;&#39;, htmlStr = &#39;&#39;;    if($(this).siblings(&#39;.qtuploader__picinputbox&#39;).hasClass(&#39;is-error&#39;)){      $.fn.toast({        &#39;parentDom&#39;: parent,        &#39;classes&#39;: &#39;isorange&#39;,        &#39;top&#39;: &#39;0&#39;,        &#39;spacing&#39;: 0,        &#39;toastContent&#39;: &#39;请设置正确范围的海报帧&#39;,        &#39;autoHide&#39;: 3000,        &#39;position&#39;: {          &#39;top&#39;: &#39;5px&#39;,          &#39;left&#39;: &#39;50%&#39;        }      });      return;    }    if (video.length > 0) {      var thumbHeight = setSize(video)[0];      var thumbWidth = setSize(video)[1];      srcStr = video.attr(&#39;src&#39;);      htmlStr = &#39;<p class="qtuploader__view"><p class="qtuploader__mask"></p><p class="qtuploader__thumb" style="width:&#39; + thumbWidth + &#39;px;height:&#39; + thumbHeight + &#39;px;margin:0 auto;"><video controls width="&#39; + thumbWidth + &#39;" height="&#39; + thumbHeight + &#39;" src="&#39; + srcStr + &#39;">您的浏览器不支持 video 标签</video></p></p>&#39;;    }    parent.append(htmlStr);    parent.find(&#39;.qtuploader__view video&#39;)[0].currentTime = $(this).siblings(&#39;.qtuploader__picinputbox&#39;).find(&#39;.qtuploader__picinput&#39;).val();    parent.find(&#39;.qtuploader__view&#39;).fadeIn();  });    /*设置海报帧预览时间*/  $(&#39;.qtuploader__items&#39;).on(&#39;keyup&#39;, &#39;.qtuploader__picinput&#39;, function() {    var parent = $(this).closest(&#39;.qtuploader__picinputbox&#39;);    var video = $(this).closest(&#39;.qtuploader__itemsbd&#39;).find(&#39;video&#39;);    var strVal = $.trim($(this).val());    console.log(strVal)    if (strVal == &#39;&#39;) {      parent.addClass(&#39;is-error&#39;);      parent.find(&#39;.qverify__font&#39;).text(&#39;请设置海报帧&#39;);    } else if (!(/^[0-9]*$/.test(strVal))) {      parent.addClass(&#39;is-error&#39;);      parent.find(&#39;.qverify__font&#39;).text(&#39;请输入数字&#39;);    } else if (video.length > 0 && strVal > video[0].duration) {      parent.addClass(&#39;is-error&#39;);      parent.find(&#39;.qverify__font&#39;).text(&#39;不超过(&#39; + video[0].duration + &#39;)&#39;);      console.log(&#39;111---&#39; + video[0].duration)    } else {      parent.removeClass(&#39;is-error&#39;);      parent.find(&#39;.qverify__font&#39;).text(&#39;请设置海报帧&#39;);    }  })  /*关闭预览*/  $(document).undelegate(&#39;.qtuploader__mask&#39;, &#39;click&#39;);  $(document).delegate(&#39;.qtuploader__mask&#39;, &#39;click&#39;, function() {    $(this).closest(&#39;.qtuploader__view&#39;).fadeOut(&#39;normal&#39;, function() {      $(this).closest(&#39;.qtuploader__view&#39;).remove();    })  })  /*设置预览大小*/  function setSize(element) {    var thumbWidth = 0, thumbHeight = 0, arr = [];    var winWidth = $(window).width(), winHeight = $(window).height();    var imgWidth = element.width(), imgHeight = element.height();    if (imgWidth > imgHeight) {      thumbHeight = parseInt(winHeight - 200);      thumbWidth = parseInt((1920 * thumbHeight) / 1080);    } else {      thumbHeight = parseInt(winHeight - 200);      thumbWidth = parseInt((1080 * thumbHeight) / 1920);    }    arr.push(thumbHeight, thumbWidth)    return arr;  }