webrtc.go

func (w *WebRtcServer) CreateNewPeerConnection(offer webrtc.SessionDescription, userID uint32, sessionKey string) (
	*ClientConnection, webrtc.SessionDescription, error) {
	answer := webrtc.SessionDescription{}

	if len(offer.SDP) == 0 || offer.Type != webrtc.SDPTypeOffer {
		return nil, answer, errors.New("invalid offer")
	}
	if len(sessionKey) == 0 {
		return nil, answer, errors.New("invalid user token")
	}
	peerConnection, err := webrtc.NewPeerConnection(webrtc.Configuration{
		ICEServers: []webrtc.ICEServer{
			{
				URLs: []string{"stun:stun.l.google.com:19302"},
			},
		},
	})

	if err != nil {
		return nil, answer, errors.New("error creating peer connection")
	}
	videoTrack, err := webrtc.NewTrackLocalStaticSample(webrtc.RTPCodecCapability{MimeType: "video/h264"}, "video", "pion")
	if err != nil {
		return nil, answer, errors.New("error create video track")

	}
	_, err = peerConnection.AddTrack(videoTrack)
	if err != nil {
		return nil, answer, errors.New("error add video track")
	}
	audioTrack, err := webrtc.NewTrackLocalStaticSample(webrtc.RTPCodecCapability{MimeType: "audio/opus"}, "audio", "pion")
	if err != nil {
		return nil, answer, errors.New("error create audio track")
	}
	_, err = peerConnection.AddTrack(audioTrack)
	if err != nil {
		return nil, answer, errors.New("error add audio track")
	}

	if err := peerConnection.SetRemoteDescription(offer); err != nil {
		return nil, answer, errors.New("error set remote Description")
	}
	answer, err = peerConnection.CreateAnswer(nil)
	if err != nil {
		return nil, answer, errors.New("error create answer")
	} else if err = peerConnection.SetLocalDescription(answer); err != nil {
		return nil, answer, errors.New("error set local Description")
	}
	clientConn := &ClientConnection{
		PeerConnection: peerConnection,
		VideoTrack:     videoTrack,
		AudioTrack:     audioTrack,
		SessionKey:     sessionKey,
	}
	peerConnection.OnConnectionStateChange(func(connectionState webrtc.PeerConnectionState) {
		switch connectionState {
		case webrtc.PeerConnectionStateDisconnected:
			peerConnection.Close()
			w.log.Info("peer connection disconnected",
				zap.Uint32("userID", userID),
			)
		case webrtc.PeerConnectionStateClosed:
			peerConnection.Close()
			w.log.Info("peer connection closed",
				zap.Uint32("userID", userID),
			)
		case webrtc.PeerConnectionStateConnected:
			w.log.Info("peer connection connected",
				zap.Uint32("userID", userID),
			)
		case webrtc.PeerConnectionStateFailed:
			w.log.Info("peer connection failed",
				zap.Uint32("userID", userID),
			)
		}
	})
	return clientConn, answer, nil
}