I have a problem with node js rtsp streaming server - node.js

Question

I made rtsp cctv streaming server with nodjs.
But it is not stable.
Some cctvs works well but others are not.
First I thought rtsp url has its own problem, but it may not.
Because the url worked well in vlc player.
I don't know what I'm missing.
below is my whole code related cctv streaming.
var express = require('express');
var router = express.Router();
var kill = require('tree-kill');
var fs = require('fs');
var path = require('path');
var ffmpeg = require('fluent-ffmpeg');
var ffmpegInstaller = require('#ffmpeg-installer/ffmpeg');
ffmpeg.setFfmpegPath(ffmpegInstaller.path)
var streams = {};
//start cctv
router.post('/', (req, res) => {
var cname = req.body.cname;
var url = req.body.url;
//if there is same cctv name
if(streams[cname] != null) {
res.status(409).send("duplicate name");
return;
};
//create dir as given cctv name;
mkdir(cname);
stream = ffmpeg(url).addOptions([
'-hls_time 5',
'-hls_list_size 10',
'-hls_flags delete_segments',
'-f hls'
]).output('./public/video/' + cname + '/' + cname + '.m3u8'); //save path
console.log("Start cctv streaming");
stream.on('error', function(err, stdout, stderr) {
console.log("cctv has been stoped");
console.log(err);
});
stream.run();
streams[cname] = stream;
res.status(201).send("OK");
});
//bring cctv pid by cctv name
router.get('/:cname', (req, res) => {
var cname = req.params.cname;
if(streams[cname] == null) {
res.status(404).send("not found such a cctv");
return;
};
var pid = streams[cname].ffmpegProc.pid;
res.send({"pid": pid});
});
//stop cctv by pid
router.delete('/:cname', async (req, res) => {
var cname = req.params.cname;
//no cctv
if(streams[cname] == null) {
res.status(404).send("not found such a cctv");
return;
};
//del dir
var filePath = './public/video/' + cname;
fs.rmdir(filePath, { recursive: true }, (err) => {
if (err) {
console.log(err)
} else {
console.log('dir is deleted.');
}
});
//var pid = streams[cname].ffmpegProc.pid;
streams[cname].kill();
res.status(204).send("OK");
});
const mkdir = (name) => {
var root = './public/video/';
if(!fs.existsSync(root + name)){
fs.mkdirSync(root + name);
}
}
And this is ts file save folder.
cctv1 dosen't work well but cctv2 works well.
(cctv1 started first but created less ts file than cctv2.)