Initial commit

pkg/webrtc/conn.go

@@ -0,0 +1,195 @@
+package webrtc
+
+import (
+	"github.com/AlexxIT/go2rtc/pkg/streamer"
+	"github.com/pion/webrtc/v3"
+)
+
+const (
+	MsgTypeOffer         = "webrtc/offer"
+	MsgTypeOfferComplete = "webrtc/offer-complete"
+	MsgTypeAnswer        = "webrtc/answer"
+	MsgTypeCandidate     = "webrtc/candidate"
+)
+
+type Conn struct {
+	streamer.Element
+
+	UserAgent string
+
+	Conn *webrtc.PeerConnection
+
+	medias []*streamer.Media
+	tracks []*streamer.Track
+
+	receive int
+	send    int
+}
+
+func (c *Conn) Init() {
+	c.Conn.OnICECandidate(func(candidate *webrtc.ICECandidate) {
+		if candidate != nil {
+			c.Fire(&streamer.Message{
+				Type: MsgTypeCandidate, Value: candidate.ToJSON().Candidate,
+			})
+		}
+	})
+
+	c.Conn.OnTrack(func(remote *webrtc.TrackRemote, receiver *webrtc.RTPReceiver) {
+		for _, track := range c.tracks {
+			if track.Direction != streamer.DirectionRecvonly {
+				continue
+			}
+			if track.Codec.PayloadType != uint8(remote.PayloadType()) {
+				continue
+			}
+
+			for {
+				packet, _, err := remote.ReadRTP()
+				if err != nil {
+					return
+				}
+				if len(packet.Payload) == 0 {
+					continue
+				}
+				c.receive += len(packet.Payload)
+				_ = track.WriteRTP(packet)
+			}
+		}
+
+		panic("something wrong")
+	})
+
+	c.Conn.OnConnectionStateChange(func(state webrtc.PeerConnectionState) {
+		c.Fire(state)
+
+		// TODO: remove
+		switch state {
+		case webrtc.PeerConnectionStateConnected:
+			c.Fire(streamer.StatePlaying)
+		case webrtc.PeerConnectionStateDisconnected:
+			c.Fire(streamer.StateNull)
+		case webrtc.PeerConnectionStateFailed:
+			_ = c.Conn.Close()
+		}
+	})
+}
+
+func (c *Conn) ExchangeSDP(offer string, complete bool) (answer string, err error) {
+	sdOffer := webrtc.SessionDescription{
+		Type: webrtc.SDPTypeOffer, SDP: offer,
+	}
+	if err = c.Conn.SetRemoteDescription(sdOffer); err != nil {
+		return
+	}
+
+	//for _, tr := range c.Conn.GetTransceivers() {
+	//	switch tr.Direction() {
+	//	case webrtc.RTPTransceiverDirectionSendonly:
+	//		// disable transceivers if we don't have track
+	//		// make direction=inactive
+	//		// don't really necessary, but anyway
+	//		if tr.Sender() == nil {
+	//			if err = tr.Stop(); err != nil {
+	//				return
+	//			}
+	//		}
+	//	case webrtc.RTPTransceiverDirectionRecvonly:
+	//		// TODO: change codecs list
+	//		caps := webrtc.RTPCodecCapability{
+	//			MimeType:  webrtc.MimeTypePCMU,
+	//			ClockRate: 8000,
+	//		}
+	//		codecs := []webrtc.RTPCodecParameters{
+	//			{RTPCodecCapability: caps},
+	//		}
+	//		if err = tr.SetCodecPreferences(codecs); err != nil {
+	//			return
+	//		}
+	//	}
+	//}
+
+	var sdAnswer webrtc.SessionDescription
+	sdAnswer, err = c.Conn.CreateAnswer(nil)
+	if err != nil {
+		return
+	}
+
+	//var sd *sdp.SessionDescription
+	//sd, err = sdAnswer.Unmarshal()
+	//for _, media := range sd.MediaDescriptions {
+	//	if media.MediaName.Media != "audio" {
+	//		continue
+	//	}
+	//	for i, attr := range media.Attributes {
+	//		if attr.Key == "sendonly" {
+	//			attr.Key = "inactive"
+	//			media.Attributes[i] = attr
+	//			break
+	//		}
+	//	}
+	//}
+	//var b []byte
+	//b, err = sd.Marshal()
+	//sdAnswer.SDP = string(b)
+
+	if err = c.Conn.SetLocalDescription(sdAnswer); err != nil {
+		return
+	}
+
+	if complete {
+		<-webrtc.GatheringCompletePromise(c.Conn)
+		return c.Conn.LocalDescription().SDP, nil
+	}
+
+	return sdAnswer.SDP, nil
+}
+
+func (c *Conn) SetOffer(offer string) (err error) {
+	sdOffer := webrtc.SessionDescription{
+		Type: webrtc.SDPTypeOffer, SDP: offer,
+	}
+	if err = c.Conn.SetRemoteDescription(sdOffer); err != nil {
+		return
+	}
+	rawSDP := []byte(c.Conn.RemoteDescription().SDP)
+	c.medias, err = streamer.UnmarshalSDP(rawSDP)
+	return
+}
+
+func (c *Conn) GetAnswer() (answer string, err error) {
+	for _, tr := range c.Conn.GetTransceivers() {
+		if tr.Direction() != webrtc.RTPTransceiverDirectionSendonly {
+			continue
+		}
+
+		// disable transceivers if we don't have track
+		// make direction=inactive
+		// don't really necessary, but anyway
+		if tr.Sender() == nil {
+			if err = tr.Stop(); err != nil {
+				return
+			}
+		}
+	}
+
+	var sdAnswer webrtc.SessionDescription
+	sdAnswer, err = c.Conn.CreateAnswer(nil)
+	if err != nil {
+		return
+	}
+
+	if err = c.Conn.SetLocalDescription(sdAnswer); err != nil {
+		return
+	}
+
+	return sdAnswer.SDP, nil
+}
+
+func (c *Conn) remote() string {
+	for _, trans := range c.Conn.GetTransceivers() {
+		pair, _ := trans.Receiver().Transport().ICETransport().GetSelectedCandidatePair()
+		return pair.Remote.String()
+	}
+	return ""
+}