问如何使用node.js将当前正在下载的视频流式传输到html5播放器？

EN

var uri = 'magnet:?xt=urn:btih:11a2ac68a11634e980f265cb1433c599d017a759';

var engine = torrentStream(uri);    

let engineGo = function () {
      return new Promise(function (resolve, reject) {
        var engine = torrentStream(uri);
        engine.on('ready', function() {
            engine.files.forEach(function(file) {
              if (file.name.substr(file.name.length - 3) == 'mkv' || file.name.substr(file.name.length - 3) == 'mp4') {
                console.log('filename:', file.name);
                var stream = file.createReadStream();
                var writable = fs.createWriteStream(file.name);
                stream.pipe(writable);
                engine.on('download', function () {
                  console.log(file.name);
                  console.log(engine.swarm.downloaded / file.length * 100 + "%");
                  resolve(file);
                });
              }
           });
       });
     });
}

app.get('*', function (req, res) {
    if (req.url != "/Guardians.of.the.Galaxy.2014.1080p.BluRay.x264.YIFY.mp4") {
      var rpath = __dirname + '/views/index.pug';
      fs.readFile(rpath, 'utf8', function (err, str) {
        var fn = pug.compile(str, { filename: rpath, pretty: true});
        res.writeHead(200, { "Content-Type": "text/html" });
        res.write(fn());
        res.end();
      });
    } else {
      engineGo().then(function (result) {
        var filer = path.resolve(__dirname,result.name);
        fs.stat(filer, function(err, stats) {
          if (err) {
            if (err.code === 'ENOENT') {
              // 404 Error if file not found
              return res.sendStatus(404);
            }
          res.end(err);
          }
          var range = req.headers.range;
          if (!range) {
           // 416 Wrong range
           return res.sendStatus(416);
          }

          var positions = range.replace(/bytes=/, "").split("-");
          var start = parseInt(positions[0], 10);
          var total = stats.size;
          var end = positions[1] ? parseInt(positions[1], 10) : total - 1;
          var chunksize = (end - start) + 1;

          res.writeHead(206, {
            "Content-Range": "bytes " + start + "-" + end + "/" + total,
            "Accept-Ranges": "bytes",
            'Connection': 'keep-alive',
            "Content-Length": chunksize,
            "Content-Type": "video/mp4"
          });
          var stream = fs.createReadStream(filer, { start: start, end: end })
          .on("open", function() {
             stream.pipe(res);
          }).on("data", function (data) {
             console.log(data);
          }).on("error", function(err) {
             res.end(err);
          });
        });
      });
    }
});

doctype
html
  title
    |Welcome
  body
      video(id='video' src="http://localhost:8888/Guardians.of.the.Galaxy.2014.1080p.BluRay.x264.YIFY.mp4" type="video/mp4" controls)