How to seamlessly switch from data only channel to video/audio in multitrack conference without re-initializing webrtc adaptor

[timantmedia]

When a user joins a room, they start with webrtcadaptor.onlyDataChannel = true (data channel only), Then they can start a video or audio call.

When sending the command webrtcadaptor.onlyDataChannel = false; and then start a video or audio stream the Id of the A/V stream is changed to a new stream id (not the same id as when in datachannel only).

It appears that when switching from webrtcadaptor.onlyDataChannel = true to webrtcadaptor.onlyDataChannel = false, the connection is disconnected and a new connection is established with a new stream ID of the A/V stream.

What is needed is to go from datachannel only mode to normal conference mode without closing the datachannel connection and reconnecting with webrtcadaptor.onlyDataChannel = true, basically dynamically switches from one mode to the other maintaining the connection and the same stream id.

It seems to me when starting a live stream with onlyDataChannel=true then no video/audio track is created, so trying to then turn on the video/audio when the data channel is already publishing, an error is triggered error callback: "already_publishing".

So how is it possible to create a video track on the fly when already publishing the data channel?

[mekya]

Hi @timantmedia,

In order to have a seamless switch, I've created an issue here
#5392 and made some development.
It will be in new release and next release will be in about 1 or 2 weeks.

Fortunately, we've already merged the development and SNAPSHOT release is already available in npmjs for testing.
Check the live sample on codepen.io: Start WebRTC Publish without Opening Cam/Mic and Open Cam/Mic on the fly

Let me quick info for the developers:

1. Initialize the WebRTC adaptor with dummy audio and video as below

var webRTCAdaptor = new WebRTCAdaptor({
  websocket_url: "wss://test.antmedia.io:5443/WebRTCAppEE/websocket",
  localVideoElement: document.getElementById("localVideo"),
  mediaConstraints: {
    video:"dummy",
    audio:"dummy"
  }
});

2. Publish the stream

webRTCAdaptor.publish("your_stream_id");

3. Open camera and Mic on the fly

webRTCAdaptor.openStream({video:true, audio:true}, "your_stream_id");

Please pay attention that second parameter is critical and it is the stream id of your current active broadcast. webRTCAdaptor uses that value to change the tracks of the peer connection on the fly.