Stream video didn't have a duration exif - node.js

Question

I do a website to record webcam in real-time on my server.
To do this, I use Web Socket to send data of my webcam to my Node.js Server.
The record is working, but my video didn't have a duration. In other words, I can't navigate in the video. I can just read the file second by second and can't skip segment or going back in the timer. (see the GIF below)
my server code to save video :
server.on("connection", (socket) => {
console.log("Client connected");
let writeStream = null;
let id = Date.now();
let filename = `${folderStream}/video-${id}.${extensionFile}`; // example : ./video/video-1620000000000.mp4
socket.on("message", (message) => {
if (!writeStream) {
console.log("Stream started");
writeStream = fs.createWriteStream(filename);
}
writeStream.write(message);
});
socket.on("close", () => {
console.log("Stream closed");
writeStream.end();
});
});
I try to use ffmpeg, but my video is already in one file and not segmented. (maybe bad usage by me)

Answer 1

For the future users who want to do the same thing, do this :
Create a temporary file who takes all raw data :
server.on("connection", (socket) => {
console.log("Client connected");
let tempFile = null;
let id = Date.now();
let filename = `video-${id}`; // exemple : video-1620000000000
socket.on("message", (message) => {
if (!tempFile) {
console.log("Stream started");
tempFile = fs.createWriteStream(`${folderStream}/${filename}.tmp`);
}
tempFile.write(message);
});
And with the library "fluent-ffmpeg";
npm i fluent-ffmpeg
const ffmpeg = require("fluent-ffmpeg");
Don't forget to install ffmpeg in your computer.
You can create a file transcoded after the ending stream.
socket.on("close", () => {
console.log("Fin d'un stream");
tempFile.end();
ffmpeg()
.input(`${folderStream}/${filename}.tmp`)
.format(extensionFile) // const extensionFile = "mp4"
.output(`${folderTranscode}/${filename}.${extensionFile}`)
.on("end", () => {
console.log("Conversion complete");
})
.run();
});
});