Upload files with busboy module nodejs and expressjs

fileUploadsWithBusboy.js

//you do not necessary need all of the following, i copy/pasted a piece from 
//one of my projects.
var express = require('express');
var fs = require('fs');
var Busboy = require('busboy');
var mime = require('mime');
var https = require('https');
var querystring = require('querystring');

var router = express.Router();

//route used to upload vehicle photos via browser
router.post('/secure/api/upload', function(req, res) {
    logger.info("ROUTE POST /secure/api/upload");

    //in addition to input-upload field, i am expecting an input field too 
    var vehicleId = req.session["vId"];
    //I keep track of huge files
    var hugeFileSize = [];
    // I keep track of files with wrong mimetypes
    var invalidFileTypes = [];

    // 6MB size limit, I abort upload if file is over 6MB limit
    var busboy = new Busboy({
      headers: req.headers,
      limits: {
        fileSize: 6*1024*1024
      }
    });

    //keep track of when file finishes and saved in the disk, busboy is a tricky module
    var counter = 0;

    //keeping track of all files uploaded, so that later they get resided, don't have to apply to 
    //your case
    var filenames = [];

    //vehicleId must be the first field in the upload form or there could be issues
    //with busboy if you want to include other input fields in the upload form, they have to 
    //be before the upload field or you will have issue accessing them
    busboy.on('field', function(fieldname, val, fieldnameTruncated, valTruncated) {
      //add checks for field names and extract those values, for example I am expecting a 
      //hidden field with name (vehicleId)
      if(fieldname == 'vehicleId')
        vehicleId = val;
    });

    //assuming that vehicleId is not null, already processed.
    busboy.on('file', function(fieldname, file, filename, encoding, mimetype) {
      //validate against empty file fields
      if(filename.length > 0) {
          // validate file mimetype
          if(mimetype != 'image/png' && mimetype != 'image/jpeg' && mimetype != 'image/tiff'){
            //keeping track of invalid files, N/A 
            invalidFileTypes.push(filename);
            
            //Ignore the upload, move on to next one
            file.resume();
          } else {
            /*
            * As soon as 6 MB limit is reached, the rest of the data is skipped hence,
            * uploading 50 GB would never be possible because after 2.1 MB no more data
            * is read and the stream is saved as is and consequently deleted.
            *
            */
            
            //Just keeps track of file uploads (how many uploaded). 
            counter++;

            //Just keeps track of names of files uploaded, for later resizing purpose.
            filenames.push(filename);

            file.on('limit', function(){
              //console.log('file size over 6 MB.');
              hugeFileSize.push(filename);

              //if the file was large in size then decrement the counter as it will be deleted anyways
              counter--;

              //delete the file that is large in size
              fs.unlink(__dirname + '/../photos/' + vehicleId + '/' + filename);
            });

            //storing the uploaded photo
            fstream = fs.createWriteStream(__dirname + '/../photos/' + vehicleId + '/' + filename);
            file.pipe(fstream);

            fstream.on('close', function() {
              //file saved in disk, so decrement.
              counter--;
            });
          }
        } else {
          file.resume();
        }
      });

      busboy.on('finish', function() {
        //console.info('Busboy uploading finished!');
      });
      return req.pipe(busboy);
    }
  });

can you help me upload video optimize script reference. i am new in nodejs.