Generate transceivers from incoming SDP.

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/pion/ice/v2 v2.0.14
 	github.com/pion/rtcp v1.2.6
 	github.com/pion/rtp v1.6.2
+	github.com/pion/sdp/v3 v3.0.3
 	github.com/pion/webrtc/v3 v3.0.2-0.20201230060242-921608c26b93
 	golang.org/x/crypto v0.0.0-20201217014255-9d1352758620
 )

rtpconn/rtpconn.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/pion/rtcp"
 	"github.com/pion/rtp"
+	"github.com/pion/sdp/v3"
 	"github.com/pion/webrtc/v3"
 
 	"github.com/jech/galene/conn"
@@ -458,30 +459,29 @@ func pushConn(up *rtpUpConnection, g *group.Group, cs []group.Client) {
 	}(g, cs)
 }
 
-func newUpConn(c group.Client, id string, labels map[string]string) (*rtpUpConnection, error) {
-	pc, err := c.Group().API().NewPeerConnection(*ice.ICEConfiguration())
+func newUpConn(c group.Client, id string, labels map[string]string, offer string) (*rtpUpConnection, error) {
+	var o sdp.SessionDescription
+	err := o.Unmarshal([]byte(offer))
 	if err != nil {
 		return nil, err
 	}
 
-	_, err = pc.AddTransceiverFromKind(webrtc.RTPCodecTypeAudio,
-		webrtc.RtpTransceiverInit{
-			Direction: webrtc.RTPTransceiverDirectionRecvonly,
-		},
-	)
+	pc, err := c.Group().API().NewPeerConnection(*ice.ICEConfiguration())
 	if err != nil {
-		pc.Close()
 		return nil, err
 	}
 
-	_, err = pc.AddTransceiverFromKind(webrtc.RTPCodecTypeVideo,
-		webrtc.RtpTransceiverInit{
-			Direction: webrtc.RTPTransceiverDirectionRecvonly,
-		},
-	)
-	if err != nil {
-		pc.Close()
-		return nil, err
+	for _, m := range o.MediaDescriptions {
+		_, err = pc.AddTransceiverFromKind(
+			webrtc.NewRTPCodecType(m.MediaName.Media),
+			webrtc.RtpTransceiverInit{
+				Direction: webrtc.RTPTransceiverDirectionRecvonly,
+			},
+		)
+		if err != nil {
+			pc.Close()
+			return nil, err
+		}
 	}
 
 	up := &rtpUpConnection{id: id, pc: pc, labels: labels}

rtpconn/webclient.go

@@ -206,7 +206,7 @@ func getUpConns(c *webClient) []*rtpUpConnection {
 	return up
 }
 
-func addUpConn(c *webClient, id string, labels map[string]string) (*rtpUpConnection, bool, error) {
+func addUpConn(c *webClient, id string, labels map[string]string, offer string) (*rtpUpConnection, bool, error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
@@ -222,7 +222,7 @@ func addUpConn(c *webClient, id string, labels map[string]string) (*rtpUpConnect
 		return old, false, nil
 	}
 
-	conn, err := newUpConn(c, id, labels)
+	conn, err := newUpConn(c, id, labels, offer)
 	if err != nil {
 		return nil, false, err
 	}
@@ -488,7 +488,7 @@ func gotOffer(c *webClient, id string, sdp string, renegotiate bool, labels map[
 		delUpConn(c, id)
 	}
 
-	up, isnew, err := addUpConn(c, id, labels)
+	up, isnew, err := addUpConn(c, id, labels, sdp)
 	if err != nil {
 		return err
 	}