Not able to Show live camera RTSP streaming with Angular

问题

I'm developing a web application with angular, I need to add a window that shows a live RTSP streaming. After searching I found that can be done with JSMpeg js library. In the server side I found this nodejs example

Stream = require('node-rtsp-stream')
stream = new Stream({
  name: 'name',
  streamUrl: 'rtsp_url',
  wsPort: 9999,
  ffmpegOptions: { // options ffmpeg flags
    '-stats': '', // an option with no neccessary value uses a blank string
    '-r': 30 // options with required values specify the value after the key
  }
})

in the web side I tried as a first step a simple HTML5 example:

<html>
<body>
<div>
    <canvas id="canvas"  width="1920" height="1080" style="display: block; width: 40%;"></canvas>
</div>
</body>

<script type="text/javascript" src="jsmpeg.min.js"></script>
<script type="text/javascript">
    //var ws = new WebSocket('ws://localhost:9999');
    player = new JSMpeg.Player('ws://localhost:9999', {
      canvas: document.getElementById('canvas'), autoplay: true, audio: false, loop: true
    })  
</script>
</html>

This HTML5 page works fine and I got in my web page a live streaming. After that I tried to adapt this HTML code to angular, I installed as first JSMpeg with npm:

npm install jsmpeg-player --save

I added the canvas tag to the corresponding html file:

<canvas #streaming id="canvas"  width="1920" height="1080" style="display: block; width: 40%;"></canvas>

Then I tried to adapt the js script to a ts script in the corresponding component like that:

@ViewChild('streaming', {static: false}) streamingcanvas: ElementRef; 

constructor( ... ) { }

ngOnInit() {
    ....
    let player = new JSMpeg.Player('ws://localhost:9999', {
        canvas: this.streamingcanvas, autoplay: true, audio: false, loop: true
      })
}

the result that I get is that the canvas tag is added but no streaming in my web page an no script errors in the console. I checked the traffic in the browser:

and seems that the nodejs server receives the websocket request as described in his traces:

but as I said no streaming in my page:

My question is: what's missing in my ts code? what should I fix?

回答1:

change in ngOnInit "this.streamingcanvas" by "this.streamingcanvas.nativeElement" it should be like this

ngOnInit() {
...
let player = new JSMpeg.Player('ws://localhost:9999', { canvas: this.streamingcanvas.nativeElement, autoplay: true, audio: false, >loop: true }) }

来源：https://stackoverflow.com/questions/58899464/not-able-to-show-live-camera-rtsp-streaming-with-angular

标签

javascript

angular

typescript

live-streaming