webrtc onaddstream not being called on first peer

Question

I have created below script which is part of a hybrid application, sometime it function properly and I can receive/send audio/video calls , but sometime onaddstream or ontrack isn't even called from the sender side, but spd packets are being sent via socket, I have tried both (onaddstream or ontrack) but no success:

here to send the offer from pc:

  sendOffer() {
    let that = this;
    that.call_status = 'connecting';

    let call_type;
    if (that.call_type == 'audio')
      call_type = { video: false, audio: true };
    else
      call_type = { video: true, audio: true };

    that.pc = new RTCPeerConnection(that.peerConnectionConfig);
    that.haveGum = navigator.mediaDevices.getUserMedia(call_type)
      .then(stream => {
        that.pc.addStream(that.from_video.nativeElement.srcObject = stream);
        that.from_video.nativeElement.style.display = 'block';
      }).then(() => that.pc.createOffer())
      .then(d => that.pc.setLocalDescription(d))
      .catch(log => { alert(log) });

    that.pc.oniceconnectionstatechange = function (e) {

      that.call_status = that.pc.iceConnectionState;
      if (that.pc.iceConnectionState == 'disconnected') {
        console.log('Disconnected');
      }
    }

    that.pc.onaddstream = e => {
      that.to_video.nativeElement.srcObject = e.stream;
    };


    that.pc.onicecandidate = e => {

      if (e.candidate) {
        return;
      }
        that.offerSent = true;
        that.socket.emit('sdp-offer', {
          from: that.user,
          sdp: that.pc.localDescription.sdp,
          call_type: call_type
        });
    };

    that.socket.on('sdp-offer-reply', (sdp: any) => {
      that.pc.setRemoteDescription(new RTCSessionDescription(({ type: "answer", sdp: sdp.sdp }))).catch(log => console.log(log));
    });

    that.socket.on('call-closed', (sdp: any) => {
      that.closeConnection();
    });
  }

and here on other device pc2 when accept answer:

  answerCall() {
    let that = this;

    let call_type;
    if (this.call_type == 'audio')
      call_type = { video: false, audio: true };
    else
      call_type = { video: true, audio: true };

    that.pc2 = new RTCPeerConnection(this.peerConnectionConfig);
    that.haveGum = navigator.mediaDevices.getUserMedia(call_type)
      .then(stream => {
        that.pc2.addStream(this.from_video.nativeElement.srcObject = stream);
      });

    that.pc2.oniceconnectionstatechange = function (e) {
        console.log(that.pc2.iceConnectionState);
    }
    that.pc2.onaddstream = e => {
      that.to_video.nativeElement.srcObject = e.stream;
      that.to_video.nativeElement.style.display = 'block';
    };

    if (that.pc2.signalingState != "stable") {
      that.call_status = that.pc2.signalingState;
      alert("not stable");
      return;
    }

    that.pc2.setRemoteDescription(new RTCSessionDescription(({ type: "offer", sdp: this.sdp.sdp })))
      .then(() => that.pc2.createAnswer())
      .then(d => {
        that.sendSdpAnswer = d; that.pc2.setLocalDescription(d);
        this.call_connected = true;
      })
      .catch(log => console.log(log));
    that.pc2.onicecandidate = e => {
      if (e.candidate) {
        console.log("not e.candidate");
        return;
      }
      that.socket.emit('offeraccepted', {
        from: that.user,
        sdp: that.sendSdpAnswer.sdp
      });
    };


    that.socket.on('call-closed', (sdp: any) => {
      that.closeConnection();
      that.call_status = "Hung Up";
    });
  }

and here is final function I am calling to close the peer connection on both sides when call ends:

  closeConnection() {
    if (typeof this.pc !== "undefined" && this.pc.signalingState != "closed") {
      this.pc.close();
    }
    if (typeof this.pc2 !== "undefined" && this.pc2.signalingState != "closed") {
      this.pc2.close();
    }
  }

I am using webrtc latest-adapter.js with socket.io as signaling server. First I emit event sdp-offer on pc to send the sdp packets and on pc2 I receive sdp-offer-incoming from node server, than pc2 emit offeraccepted and attach sdp data with event, on pc1 i receive sdp packets and it display the video/audio on both pc's as it should but sometime sender doest receive the stream, But receiver always have both videos.

user969068 user969068 · Accepted Answer · 2017-08-08T12:00:03

I had to pass constraints when creating offer:

      this.pc.createOffer({
        offerToReceiveAudio: 1,
        offerToReceiveVideo: 1
      })

webrtc onaddstream not being called on first peer

1 Answers