How to get specific chunks from stream node js - node.js

Question

I'm trying to make a server that are used like a "CDN proxy".
We have
S1: main server that has all media
S2 CDN proxy
client
The aim is:
obtain a stream from server1 (S1)
(I'm using this follow link as placeholder, the effective link could be a temp link)
axios.get(link, { responseType: "stream", adapter: httpAdapter })
.then((axiosResponse: any) => { ... })
since I have a stream, I don't need to proxy the entire media to the client, but just a chunk (specified from the client)
I don't know how to retrieve a specific chunk without download all chunks up to the desired chunk.
This is a scratch:
import express, { Request, Response } from 'express';
import expressAsyncHandler from 'express-async-handler';
import * as http from 'http';
const axios = require("axios");
const httpAdapter = require("axios/lib/adapters/http");
const app = express();
const HTTP_PORT = 3000;
var server = http.createServer(app);
const link = 'https://images.all-free-download.com/footage_preview/mp4/city_panorama_6891675.mp4';
app.get('/video.mp4', expressAsyncHandler(async (req: Request, res: Response) => {
axios.get(link, { responseType: "stream", adapter: httpAdapter })
.then((axiosResponse: any) => {
let stream = axiosResponse?.data;
const fileSize = axiosResponse["headers"]["content-length"];
const range = req.headers.range
if (range) {
const parts = range.replace(/bytes=/, "").split("-")
const start = parseInt(parts[0], 10)
const end = parts[1]
? parseInt(parts[1], 10)
: fileSize - 1
const chunksize = (end - start) + 1
/*******************************/
const streamChunk = /* GET CHUNCK FROM STREAM WITHOUT OVERHEAD */ null;
/*******************************/
const head = {
'Content-Range': `bytes ${start}-${end}/${fileSize}`,
'Accept-Ranges': 'bytes',
'Content-Length': chunksize,
'Content-Type': 'video/mp4',
}
res.writeHead(206, head);
streamChunk.pipe(res);
} else {
const head = {
'Content-Length': fileSize,
'Content-Type': 'video/mp4',
}
res.writeHead(200, head)
stream.pipe(res)
}
})
}));
server.listen(HTTP_PORT, () => {
console.log("Running on port: " + HTTP_PORT);
});
I hope someone can help me.
Thanks in advice :)
UPDATE
Follow code works on VLC
import express, { Request, Response } from 'express';
import expressAsyncHandler from 'express-async-handler';
import * as http from 'http';
import * as https from 'https';
const axios = require("axios");
const httpAdapter = require("axios/lib/adapters/http");
const app = express();
const HTTP_PORT = 3000;
var server = http.createServer(app);
/************************************************/
// PREVENT EXCEPTION CLOSURE
process.on('uncaughtException', function (err) {
console.error(err);
console.log("Node NOT Exiting...");
});
/************************************************/
const link = 'https://samplelib.com/lib/preview/mp4/sample-30s.mp4';
app.get('/video.mp4', expressAsyncHandler(async (req: Request, res: Response) => {
if (req.socket.destroyed) {
return;
}
delete req.headers.referer;
let head;
let status;
const range = req.headers.range
const axiosResponseHead = await axios.head(link)
const fileSize = axiosResponseHead["headers"]["content-length"];
const agent = new https.Agent({
rejectUnauthorized: false
});
console.log(range)
if (range) {
req.headers.host = new URL(link).hostname;
const parts = range?.replace(/bytes=/, "")?.split("-")
const start = parseInt(parts[0], 10)
const end = parts[1]
? parseInt(parts[1], 10)
: fileSize - 1
const chunksize = (end - start) + 1
head = {
'Content-Range': `bytes ${start}-${end}/${fileSize}`,
'range': `bytes=${start}-${end}`,
'Accept-Ranges': 'bytes',
'Content-Length': chunksize,
'Content-Type': 'video/mp4',
}
status = 206;
req.headers.range = head.range
} else {
head = {
'Content-Length': fileSize,
'Content-Type': 'video/mp4',
}
status = 200;
}
console.log(req.headers)
console.log(head)
console.log("==================================")
let axiosResponse: any
let stream: any;
res.on('close', function () {
stream?.destroy();
});
let instance = axios.create();
axiosResponse = await instance.get(link, {
responseType: "stream", adapter: httpAdapter, headers: req.headers, httpsAgent: agent
})
stream = axiosResponse?.data;
res.writeHead(status, head)
stream.pipe(res, { end: true });
}));
server.listen(HTTP_PORT, () => {
console.log("Running on port: " + HTTP_PORT);
});
function sleep(ms: number) {
return new Promise(resolve => setTimeout(resolve, ms));
}