//第三条地址
https://aweme.snssdk.com/aweme/v1/play/?video_id=v0300f760000c0fq7t5t1gvidv0rdtag&line=0&ratio=720p&media_type=4&vr_type=0&improve_bitrate=0&is_play_url=1&source=PackSourceEnum_DOUYIN_REFLOW
 
//上面保存的
https://aweme.snssdk.com/aweme/v1/playwm/?video_id=v0300f760000c0fq7t5t1gvidv0rdtag&ratio=720p&line=0

//下载视频
 
const path=require('path')
const fs=require('fs')
const request=require('request')

function downVideo(url) {
 var fileName=`${+new Date()}.mp4`
 var fullPath=path.resolve('https://www.jb51.net/article/videos/' + fileName);
 console.log('开始下载视频：', fileName);
 request(encodeURI(url)).on('error', function (err) {
 console.log(error)
 }).pipe(fs.createWriteStream(fullPath)).on('finish', ()=> {
 console.log('视频下载成功');
 })
 
}
 
const url='http://v6-z.douyinvod.com/719423c89357069fffd503a6698436f9/60342b2c/video/tos/cn/tos-cn-ve-15/56505c3774bd46de98d6a49e2315e292/?a=1128&br=4996&bt=1249&cd=0%7C0%7C0&ch=0&cr=0&cs=0&cv=1&dr=0&ds=3&er=&l=2021022300074001020410813542130635&lr=&mime_type=video_mp4&pl=0&qs=0&rc=and1eWxqd3d0MzMzOWkzM0ApZTw2NWhoZGRpNzs7ZTc4OWcpaGRqbGRoaGRmXmEtYXMuMjRjYC0tNC0wc3MzLjY1XzMxNjE2Ly4xMDFhOmNwb2wrbStqdDo%3D&vl=&vr='
downVideo(url)

//获取api地址
 
function getApiUrl(url){
 //前端传过来的地址 进行重定向拿到 item_ids 并且返回
 return new Promise(resolve=> {
 request(url, (error, response)=> {
  if (!error && response.statusCode==200) {
  let href=https://www.jb51.net/article/response.request.href;
  let id='';
  id=href.match(/video/(\S*)/\?region/)[1];
  resolve(`https://www.iesdouyin.com/web/api/v2/aweme/iteminfo/?item_ids=${id}`);
  } else {
  resolve(false)
  }
 })
 });
}
 
getApiUrl('xxx').then(api=>{
//xxx
})