获取视频第一帧,以及后续上传

javascript 复制代码

// 获取视频基本信息
const getVideoBasicInfo = (videoSrc) => {
    return new Promise((resolve, reject) => {
        const video = document.createElement("video");
        video.src = videoSrc;
        // 视频一定要添加预加载
        video.preload = "auto";
        // 视频一定要同源或者必须允许跨域
        video.crossOrigin = "Anonymous";
        // 监听：异常
        video.addEventListener("error", (error) => {
            reject(error);
        });
        // 监听：加载完成基本信息,设置要播放的时常
        video.addEventListener("loadedmetadata", () => {
            const videoInfo = {
                video,
                width: video.videoWidth,
                height: video.videoHeight,
                duration: video.duration,
            };
            resolve(videoInfo);
        });
    });
};

javascript 复制代码

// 将获取到的视频信息，转化为图片地址
const getVideoPosterInfo = (videoInfo) => {
    return new Promise((resolve) => {
        const { video, width, height } = videoInfo;
        video.addEventListener("canplay", () => {
            const canvas = document.createElement("canvas");
            canvas.width = width;
            canvas.height = height;
            const ctx = canvas.getContext("2d");
            ctx.drawImage(video, 0, 0, width, height);
            const posterUrl = canvas.toDataURL("image/jpg");
            resolve({ posterUrl });
        });
    });
};

此函数就是最终可以拿到图片地址的函数了。

javascript 复制代码

//获取处理后的图片地址
const getImgUrl = async (videoSrc) => {
    let videoInfo = await getVideoBasicInfo(videoSrc);
    let {posterUrl} = await getVideoPosterInfo(videoInfo);
    return posterUrl
};

拓展:

如果还需要将拿到的图片进行上传到远程服务器的处理例如阿里云或者OSS服务器中则看下面代码继续处理

javascript 复制代码

//base64转file 文件
const base64ToFile = (data) => {
  // 将base64 的图片转换成file对象上传 atob将ascii码解析成binary数据
  let binary = atob(data.split(",")[1]);
  let mime = data.split(",")[0].match(/:(.*?);/)[1];
  let array = [];
  for (let i = 0; i < binary.length; i++) {
    array.push(binary.charCodeAt(i));
  }
  let fileData = new Blob([new Uint8Array(array)], {
    type: mime,
  });
  let file = new File([fileData], `${new Date().getTime()}.png`, {
    type: mime,
  });
  return file;
}

最终上传工具就写完了。实际调用只需要传递视频地址即可。

javascript 复制代码

//获取OSS地址
const uploadImgUrl = async(videoSrc)=>{
  let imgUrl = await getImgUrl(videoSrc)
  let fileList= base64ToFile(imgUrl)
  var formData = new FormData()
  formData.set('filename', fileList)
  formData.set('merchantId', localStorage.getItem('MerchantId'))
  formData.set('Directory', 'Image')
  return new Promise((resolve, reject) => {
    axios.post(`${configs.host.test}/api/FileUpload/Upload`, formData)
      .then(res => {
        resolve(res.data);
      })
  });
}

export {
  uploadImgUrl
}