js canvas截取视频画面首帧

直接贴代码

/**
 * 截取视频画面
 * @param {*} url 视频播放链接
 * @param {*} width  画面的截取宽度
 * @param {*} height  图片的截取高度
 */
export function cutVideoCover(url, width = 960, height = 540) {
  return new Promise((reslove) => {
    let video = document.createElement('video');
    video.crossOrigin = 'anonymous'; //处理跨域
    video.src = url;
    video.width = width;
    video.height = height;
    video.preload = 'auto'; //预加载视频，以保证可稳定获取画面
    video.currentTime = 1; //指定截取几秒处的帧
    // video.autoplay = true;
    // video.muted = true;
    //当视频完成渲染
    video.onloadeddata = () => {
      let canvas = document.createElement('canvas');
      canvas.width = video.width;
      canvas.height = video.height;
      canvas.getContext('2d').drawImage(video, 0, 0, canvas.width, canvas.height); //绘制canvas
      let fileType = 'image/jpeg';

      // 返回形式1：以url形式返回，需要配置接口上传
      canvas.toBlob((blob) => {
        let blobFile = new File([blob], randomNum(100000, 1000000) + '.jpg', { type: fileType }); //转成file格式
        const params = new FormData();
        params.append('file', blobFile);
        //上传到接口转成图片链接
        commonApi
          .uploadFile(params)
          .then((res) => {
            if (res.code == 200000) {
              reslove(res.msg);
            }
          })
          .finally(() => {
            video = null; //清除video元素
          });
      }, fileType);

      //返回形式2：以base64格式返回。可直接用img标签展示
      // const base64Url = canvas.toDataURL(fileType)  //转为base64，返回
      // resolve(base64Url)
    };
  });
}



调用
cutVideoCover(videoUrl).then((res) => {
  console.log(res)  //图片地址
});