From 6c6afd6c883570b51b59c98e950bcaa56c098311 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=88=90=E4=BA=8C=E9=BE=8D?= <h2013142@mail.foxconn.com>
Date: Wed, 6 Oct 2021 18:01:48 +0800
Subject: [PATCH] feat(relay):Audioobserver supported on relaying SFU

---
 pkg/buffer/buffer.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/pkg/buffer/buffer.go b/pkg/buffer/buffer.go
index 1fd124ab8..43826f91f 100644
--- a/pkg/buffer/buffer.go
+++ b/pkg/buffer/buffer.go
@@ -165,6 +165,13 @@ func (b *Buffer) Bind(params webrtc.RTPParameters, o Options) {
 			}
 		}
 	} else if b.codecType == webrtc.RTPCodecTypeAudio {
+		if len(params.HeaderExtensions) == 0 {
+			t := &webrtc.RTPHeaderExtensionParameter{
+				URI: "urn:ietf:params:rtp-hdrext:ssrc-audio-level",
+				ID:  1,
+			}
+			params.HeaderExtensions = append(params.HeaderExtensions, *t)
+		}
 		for _, h := range params.HeaderExtensions {
 			if h.URI == sdp.AudioLevelURI {
 				b.audioLevel = true