From d236f4c6df88de5bb5b15246e055c425ee7e335a Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Thu, 13 May 2021 03:45:06 +0200
Subject: [PATCH] Work around empty track id and msid.

---
 rtpconn/webclient.go | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/rtpconn/webclient.go b/rtpconn/webclient.go
index 0678bd8..db24b47 100644
--- a/rtpconn/webclient.go
+++ b/rtpconn/webclient.go
@@ -361,9 +361,25 @@ func addDownTrackUnlocked(conn *rtpDownConnection, remoteTrack *rtpUpTrack, remo
 		}
 	}
 
+	id := remoteTrack.track.ID()
+	if id == "" {
+		log.Println("Got track with empty id")
+		id = remoteTrack.track.RID()
+	}
+	if id == "" {
+		id = remoteTrack.track.Kind().String()
+	}
+	msid := remoteTrack.track.StreamID()
+	if msid == "" {
+		log.Println("Got track with empty msid")
+		msid = remoteConn.Label()
+	}
+	if msid == "" {
+		msid = "dummy"
+	}
+
 	local, err := webrtc.NewTrackLocalStaticRTP(
-		remoteTrack.Codec(),
-		remoteTrack.track.ID(), remoteTrack.track.StreamID(),
+		remoteTrack.Codec(), id, msid,
 	)
 	if err != nil {
 		return err