Finished streaming single screen using HLS and reduced latency to 10sec

Backend/src/app/frontend/frontend.controller.ts

@@ -120,10 +120,8 @@ export class FrontendController {
     example: 'some.ts',
   })
   @Get('/hls/:filename')
-  async getHLSFiles(
-    @Param('filename') filename: string,
-  ) {
-    const id = filename.substring(0,filename.indexOf("_"));
+  async getHLSFiles(@Param('filename') filename: string) {
+    const id = filename.substring(0, filename.indexOf('_'));
     const filePath = `${__dirname}\\..\\..\\${process.env.HLS_OUTPUT_DIRECTORY}\\${id}\\${filename}`;
     const file = createReadStream(filePath);
     return new StreamableFile(file);

Backend/src/cameraStream/UDPStream.ts

@@ -0,0 +1,62 @@
+/* eslint-disable padded-blocks */
+import { Server } from 'socket.io';
+import type { Camera } from './cameraData';
+import { cameraData } from './cameraData';
+const { spawn } = require('child_process');
+const fs = require('fs');
+
+function encodeRTSPtoMpegts(camera: Camera, serverSocketInstance: Server) {
+  const ffmpegCommand = [
+    '-rtsp_transport',
+    'udp',
+    '-i',
+    camera.rtspUrl,
+    '-c:v',
+    'copy',
+    '-an',
+    '-f',
+    'mpegts',
+    '-',
+  ];
+
+  // Spawn FFmpeg process
+  const ffmpegProcess = spawn('ffmpeg', ffmpegCommand);
+
+  // Event listeners for process output
+  ffmpegProcess.stdout.on('data', (data) => {
+    console.log(`streaming`);
+    serverSocketInstance.to('clients').emit('stream', { id: camera.id, data });
+  });
+
+  ffmpegProcess.stderr.on('data', (data) => {
+    console.error(`stderr: ${data}`);
+  });
+
+  ffmpegProcess.on('close', (code) => {
+    console.log(`FFmpeg process closed with code ${code}`);
+    encodeRTSPtoMpegts(camera, serverSocketInstance);
+  });
+
+  ffmpegProcess.on('error', (err) => {
+    console.error(`Error executing FFmpeg: ${err}`);
+  });
+}
+
+// Periodically check the RTSP streams and restart transcoding for each
+function periodicCheck(serverSocketInstance: Server) {
+  console.log('Checking RTSP stream status...');
+  cameraData.forEach((camera) =>
+    encodeRTSPtoMpegts(camera, serverSocketInstance),
+  );
+}
+
+// Run once the application is run
+export function initiateCameraStream(serverSocketInstance: Server) {
+  // Run the periodic check every 10 minutes (adjust as needed)
+  setInterval(() => periodicCheck(serverSocketInstance), 10 * 60 * 1000);
+
+  // Initial transcoding for each RTSP stream
+  cameraData.forEach((camera) =>
+    encodeRTSPtoMpegts(camera, serverSocketInstance),
+  );
+}

Backend/src/cameraStream/cameraStream.gateway.ts

@@ -6,8 +6,9 @@ import {
   MessageBody,
   OnGatewayConnection,
   WsException,
+  WebSocketServer,
 } from '@nestjs/websockets';
-import { Socket } from 'socket.io';
+import { Socket, Server } from 'socket.io';
 import { AuthGuard } from '../auth/auth.guard';
 import {
   Catch,
@@ -17,6 +18,7 @@ import {
   UseGuards,
 } from '@nestjs/common';
 import { JwtService } from '@nestjs/jwt';
+import { initiateCameraStream } from './UDPStream';
 
 @Catch(WsException, HttpException)
 export class WsExceptionFilter implements WsExceptionFilter {
@@ -28,17 +30,25 @@ export class WsExceptionFilter implements WsExceptionFilter {
 type Message = { id: number; data: Buffer };
 
 @WebSocketGateway({
-  transports: ['websocket'],
+  transports: ['websocket', 'polling'],
   cors: {
     origin: '*',
+    methods: ['GET', 'POST'],
+    transports: ['websocket', 'polling'],
+    credentials: true,
   },
-  namespace: '/',
+  allowEIO3: true,
 })
 @UseGuards(AuthGuard)
 @UseFilters(WsExceptionFilter)
 export class CameraStreamGateway implements OnGatewayConnection {
+  @WebSocketServer() io: Server;
   constructor(private readonly jwtService: JwtService) {}
 
+  afterInit() {
+    // initiateCameraStream(this.io);
+  }
+
   handleConnection(@ConnectedSocket() client: Socket) {
     try {
       new AuthGuard(this.jwtService).checkToken(client.handshake.headers);
@@ -47,6 +57,7 @@ export class CameraStreamGateway implements OnGatewayConnection {
       return;
     }
     client.join('clients');
+    console.log(this.io.adapter);
   }
 
   @SubscribeMessage('message')

Backend/src/cameraStream/cameraStream.ts

@@ -34,22 +34,34 @@ function transcodeRTSPtoHLS(camera: Camera) {
   );
 
   const ffmpegCommand = [
+    '-rtsp_transport',
+    'udp',
     '-i',
     camera.rtspUrl,
     '-c:v',
     'libx264',
     '-c:a',
     'aac',
+    '-b:a',
+    '128000',
+    '-g',
+    '2',
+    '-keyint_min',
+    '2',
+    '-ac',
+    '2',
+    '-s',
+    '854x480',
+    '-b:v',
+    '800000',
     '-hls_time',
-    '3',
+    '2',
     '-hls_list_size',
-    '15',
+    '10',
+    '-start_number',
+    '1',
     '-hls_flags',
     'delete_segments',
-    '-strict',
-    'experimental',
-    '-threads',
-    '8',
     '-preset',
     'ultrafast',
     `${__dirname}\\..\\${process.env.HLS_OUTPUT_DIRECTORY}\\${camera.id}\\${camera.id}_${process.env.HLS_FILE_NAME}`,

Backend/src/main.ts

@@ -8,6 +8,8 @@ import { ValidationPipe } from '@nestjs/common';
 import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
 import { IoAdapter } from '@nestjs/platform-socket.io';
 import { initiateCameraStream } from './cameraStream/cameraStream';
+const dgram = require('dgram');
+
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
   app.useGlobalPipes(new ValidationPipe());
@@ -42,7 +44,7 @@ async function bootstrap() {
   );
 
   initiateCameraStream();
+
 }
 
 bootstrap();
-