vue项目中利用后端接口返回的视频地址获取第一帧作为数据封面展示

在项目开发中遇到了一个需求 ，项目中视频考虑节省存储有前端自己根据视频地址进行获取封面第一帧进行展示

1：利用转成base64进行获取封面

//封装函数 
 getVideoBase64(url) {
            return new Promise(function (resolve, reject) {
                let dataURL = "";
                let video = document.createElement("video");
                video.setAttribute("crossOrigin", "anonymous"); //处理跨域
                video.setAttribute("src", url);
                video.setAttribute("width", 400);
                video.setAttribute("height", 240);
                video.setAttribute("preload", "auto");
                video.setAttribute('crossOrigin', 'anonymous');
                video.addEventListener("loadeddata", function () {
                    let canvas = document.createElement("canvas"),
                        width = video.width, //canvas的尺寸和图片一样
                        height = video.height;
                    canvas.width = width;
                    canvas.height = height;
                    canvas.getContext("2d").drawImage(video, 0, 0, width, height); //绘制canvas
                    dataURL = canvas.toDataURL("image/jpeg"); //转换为base64
                    resolve(dataURL);
                });
            })
        },




//使用该函数
       if (res.data.data.clipList) {  //数据
          setTimeout(() => {
            //item.videoUrl  视频地址    item.coverUrl  图片地址
            res.data.data.clipList.forEach((item, index) => {
              this.getVideoBase64(item.videoUrl).then((data) => {
                item.coverUrl = data
              });
            });
          }, 1000);
        }

暂未解决弊端：在进行获取第一帧时有些地址偶尔是未获取到第一帧，获取不稳定

2：利用canvas来获取视频第一帧作为封面

    //转换第一帧
    cutPicture(item) {
      let video = document.createElement("video");
      video.style = 'position:fixed; top: 9999px;left:9999px;z-index:-9999'
      video.preload = 'metadata'
      video.currentTime = 1   //截取的视频第一秒作为图片
      video.src = item.videoUrl
      video.setAttribute('crossOrigin', 'anonymous');
      video.width = 113
      video.height = 75
      document.body.appendChild(video)
      video.onloadeddata = function () {
        let canvas = document.createElement('canvas')
        canvas.width = 113
        canvas.height = 75
        canvas.getContext('2d').drawImage(video, 0, 0, video.clientWidth, video.clientHeight)
        var oGrayImg = canvas.toDataURL('image/jpeg');
        item.videoUrl = oGrayImg
        this.remove()
      }
      return item
    },

推荐利用canvas来进行获取视频第一帧作为封面展示 该函数调用获取相对稳定 推荐使用