webrtc: support reading and proxying stereo PCMU/PCMA tracks

go.mod

@@ -20,7 +20,7 @@ require (
 	github.com/gorilla/websocket v1.5.1
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/matthewhartstonge/argon2 v1.0.0
-	github.com/pion/ice/v2 v2.3.11
+	github.com/pion/ice/v2 v2.3.24
 	github.com/pion/interceptor v0.1.29
 	github.com/pion/logging v0.2.2
 	github.com/pion/rtcp v1.2.14
@@ -58,12 +58,12 @@ require (
 	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
 	github.com/pion/datachannel v1.5.5 // indirect
 	github.com/pion/dtls/v2 v2.2.7 // indirect
-	github.com/pion/mdns v0.0.9 // indirect
+	github.com/pion/mdns v0.0.12 // indirect
 	github.com/pion/randutil v0.1.0 // indirect
-	github.com/pion/sctp v1.8.8 // indirect
+	github.com/pion/sctp v1.8.16 // indirect
 	github.com/pion/srtp/v2 v2.0.18 // indirect
 	github.com/pion/stun v0.6.1 // indirect
-	github.com/pion/transport/v2 v2.2.3 // indirect
+	github.com/pion/transport/v2 v2.2.4 // indirect
 	github.com/pion/turn/v2 v2.1.3 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
@@ -81,4 +81,4 @@ replace code.cloudfoundry.org/bytefmt => github.com/cloudfoundry/bytefmt v0.0.0-
 
 replace github.com/pion/ice/v2 => github.com/aler9/ice/v2 v2.0.0-20231112223552-32d34dfcf3a1
 
-replace github.com/pion/webrtc/v3 => github.com/aler9/webrtc/v3 v3.0.0-20231112223655-e402ed2689c6
+replace github.com/pion/webrtc/v3 => github.com/aler9/webrtc/v3 v3.0.0-20240527213244-d3ff0bd9230f

go.sum

@@ -12,8 +12,8 @@ github.com/alecthomas/repr v0.4.0 h1:GhI2A8MACjfegCPVq9f1FLvIBS+DrQ2KQBFZP1iFzXc
 github.com/alecthomas/repr v0.4.0/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
 github.com/aler9/ice/v2 v2.0.0-20231112223552-32d34dfcf3a1 h1:fD6eZt+3/t8bzFn6ZZA2eP63xBP06v3EPfPJu8DO8ys=
 github.com/aler9/ice/v2 v2.0.0-20231112223552-32d34dfcf3a1/go.mod h1:lT3kv5uUIlHfXHU/ZRD7uKD/ufM202+eTa3C/umgGf4=
-github.com/aler9/webrtc/v3 v3.0.0-20231112223655-e402ed2689c6 h1:wMd3D1mLghoYYh31STig8Kwm2qi8QyQKUy09qUUZrVw=
-github.com/aler9/webrtc/v3 v3.0.0-20231112223655-e402ed2689c6/go.mod h1:1CaT2fcZzZ6VZA+O1i9yK2DU4EOcXVvSbWG9pr5jefs=
+github.com/aler9/webrtc/v3 v3.0.0-20240527213244-d3ff0bd9230f h1:IcGmhy+mh/cDCHR8BBDI8iUGeV2/O1A/qqoR3yi62Z0=
+github.com/aler9/webrtc/v3 v3.0.0-20240527213244-d3ff0bd9230f/go.mod h1:1CaT2fcZzZ6VZA+O1i9yK2DU4EOcXVvSbWG9pr5jefs=
 github.com/asticode/go-astikit v0.30.0 h1:DkBkRQRIxYcknlaU7W7ksNfn4gMFsB0tqMJflxkRsZA=
 github.com/asticode/go-astikit v0.30.0/go.mod h1:h4ly7idim1tNhaVkdVBeXQZEE3L0xblP7fCWbgwipF0=
 github.com/asticode/go-astits v1.13.0 h1:XOgkaadfZODnyZRR5Y0/DWkA9vrkLLPLeeOvDwfKZ1c=
@@ -143,8 +143,8 @@ github.com/pion/interceptor v0.1.29/go.mod h1:ri+LGNjRUc5xUNtDEPzfdkmSqISixVTBF/
 github.com/pion/logging v0.2.2 h1:M9+AIj/+pxNsDfAT64+MAVgJO0rsyLnoJKCqf//DoeY=
 github.com/pion/logging v0.2.2/go.mod h1:k0/tDVsRCX2Mb2ZEmTqNa7CWsQPc+YYCB7Q+5pahoms=
 github.com/pion/mdns v0.0.7/go.mod h1:4iP2UbeFhLI/vWju/bw6ZfwjJzk0z8DNValjGxR/dD8=
-github.com/pion/mdns v0.0.9 h1:7Ue5KZsqq8EuqStnpPWV33vYYEH0+skdDN5L7EiEsI4=
-github.com/pion/mdns v0.0.9/go.mod h1:2JA5exfxwzXiCihmxpTKgFUpiQws2MnipoPK09vecIc=
+github.com/pion/mdns v0.0.12 h1:CiMYlY+O0azojWDmxdNr7ADGrnZ+V6Ilfner+6mSVK8=
+github.com/pion/mdns v0.0.12/go.mod h1:VExJjv8to/6Wqm1FXK+Ii/Z9tsVk/F5sD/N70cnYFbk=
 github.com/pion/randutil v0.1.0 h1:CFG1UdESneORglEsnimhUjf33Rwjubwj6xfiOXBa3mA=
 github.com/pion/randutil v0.1.0/go.mod h1:XcJrSMMbbMRhASFVOlj/5hQial/Y8oH/HVo7TBZq+j8=
 github.com/pion/rtcp v1.2.10/go.mod h1:ztfEwXZNLGyF1oQDttz/ZKIBaeeg/oWbRYqzBM9TL1I=
@@ -156,8 +156,9 @@ github.com/pion/rtp v1.8.3/go.mod h1:pBGHaFt/yW7bf1jjWAoUjpSNoDnw98KTMg+jWWvziqU
 github.com/pion/rtp v1.8.7-0.20240429002300-bc5124c9d0d0 h1:yPAphilskTN7U3URvBVxlVr0PzheMeWqo7PaOqh//Hg=
 github.com/pion/rtp v1.8.7-0.20240429002300-bc5124c9d0d0/go.mod h1:pBGHaFt/yW7bf1jjWAoUjpSNoDnw98KTMg+jWWvziqU=
 github.com/pion/sctp v1.8.5/go.mod h1:SUFFfDpViyKejTAdwD1d/HQsCu+V/40cCs2nZIvC3s0=
-github.com/pion/sctp v1.8.8 h1:5EdnnKI4gpyR1a1TwbiS/wxEgcUWBHsc7ILAjARJB+U=
 github.com/pion/sctp v1.8.8/go.mod h1:igF9nZBrjh5AtmKc7U30jXltsFHicFCXSmWA2GWRaWs=
+github.com/pion/sctp v1.8.16 h1:PKrMs+o9EMLRvFfXq59WFsC+V8mN1wnKzqrv+3D/gYY=
+github.com/pion/sctp v1.8.16/go.mod h1:P6PbDVA++OJMrVNg2AL3XtYHV4uD6dvfyOovCgMs0PE=
 github.com/pion/sdp/v3 v3.0.6/go.mod h1:iiFWFpQO8Fy3S5ldclBkpXqmWy02ns78NOKoLLL0YQw=
 github.com/pion/sdp/v3 v3.0.9 h1:pX++dCHoHUwq43kuwf3PyJfHlwIj4hXA7Vrifiq0IJY=
 github.com/pion/sdp/v3 v3.0.9/go.mod h1:B5xmvENq5IXJimIO4zfp6LAe1fD9N+kFv+V/1lOdz8M=
@@ -169,8 +170,9 @@ github.com/pion/transport v0.14.1 h1:XSM6olwW+o8J4SCmOBb/BpwZypkHeyM0PGFCxNQBr40
 github.com/pion/transport v0.14.1/go.mod h1:4tGmbk00NeYA3rUa9+n+dzCCoKkcy3YlYb99Jn2fNnI=
 github.com/pion/transport/v2 v2.0.0/go.mod h1:HS2MEBJTwD+1ZI2eSXSvHJx/HnzQqRy2/LXxt6eVMHc=
 github.com/pion/transport/v2 v2.2.1/go.mod h1:cXXWavvCnFF6McHTft3DWS9iic2Mftcz1Aq29pGcU5g=
-github.com/pion/transport/v2 v2.2.3 h1:XcOE3/x41HOSKbl1BfyY1TF1dERx7lVvlMCbXU7kfvA=
 github.com/pion/transport/v2 v2.2.3/go.mod h1:q2U/tf9FEfnSBGSW6w5Qp5PFWRLRj3NjLhCCgpRK4p0=
+github.com/pion/transport/v2 v2.2.4 h1:41JJK6DZQYSeVLxILA2+F4ZkKb4Xd/tFJZRFZQ9QAlo=
+github.com/pion/transport/v2 v2.2.4/go.mod h1:q2U/tf9FEfnSBGSW6w5Qp5PFWRLRj3NjLhCCgpRK4p0=
 github.com/pion/transport/v3 v3.0.1/go.mod h1:UY7kiITrlMv7/IKgd5eTUcaahZx5oUN3l9SzK5f5xE0=
 github.com/pion/transport/v3 v3.0.2 h1:r+40RJR25S9w3jbA6/5uEPTzcdn7ncyU44RWCbHkLg4=
 github.com/pion/transport/v3 v3.0.2/go.mod h1:nIToODoOlb5If2jF9y2Igfx3PFYWfuXi37m0IlWa/D0=
@@ -215,7 +217,6 @@ golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5y
 golang.org/x/crypto v0.8.0/go.mod h1:mRqEX+O9/h5TFCrQhkgjo2yKi0yYA+9ecGkdQoHrywE=
 golang.org/x/crypto v0.10.0/go.mod h1:o4eNf7Ede1fv+hwOwZsTHl9EsPFO6q6ZvYR8vYfY45I=
 golang.org/x/crypto v0.12.0/go.mod h1:NF0Gs7EO5K4qLn+Ylc+fih8BSTeIjAP05siRnAh98yw=
-golang.org/x/crypto v0.13.0/go.mod h1:y6Z2r+Rw4iayiXXAIxJIDAJ1zMW4yaTpebo8fPOliYc=
 golang.org/x/crypto v0.23.0 h1:dIJU/v2J8Mdglj/8rJ6UUOM3Zc9zLZxVZwwxMooUSAI=
 golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
@@ -236,7 +237,6 @@ golang.org/x/net v0.9.0/go.mod h1:d48xBJpPfHeWQsugry2m+kC02ZBRGRgulfHnEXEuWns=
 golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
 golang.org/x/net v0.11.0/go.mod h1:2L/ixqYpgIVXmeoSA/4Lu7BzTG4KIyPIryS4IsOd1oQ=
 golang.org/x/net v0.14.0/go.mod h1:PpSgVXXLK0OxS0F31C1/tv6XNguvCrnXIDrFMspZIUI=
-golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
 golang.org/x/net v0.25.0 h1:d/OCCoBEUq33pjydKrGQhw7IlUPI2Oylr+8qLx49kac=
 golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -268,7 +268,6 @@ golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -280,7 +279,6 @@ golang.org/x/term v0.7.0/go.mod h1:P32HKFT3hSsZrRxla30E9HqToFYAQPCMs/zFMBUFqPY=
 golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
 golang.org/x/term v0.9.0/go.mod h1:M6DEAAIenWoTxdKrOltXcmDY3rSplQUkrvaDU5FcQyo=
 golang.org/x/term v0.11.0/go.mod h1:zC9APTIj3jG3FdV/Ons+XE1riIZXG4aZ4GTHiPZJPIU=
-golang.org/x/term v0.12.0/go.mod h1:owVbMEjm3cBLCHdkQu9b1opXd4ETQWc3BhuQGKgXgvU=
 golang.org/x/term v0.20.0 h1:VnkxpohqXaOBYJtBmEppKUG6mXpi+4O6purfc2+sMhw=
 golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -293,7 +291,6 @@ golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.10.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
-golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
 golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/time v0.5.0 h1:o7cqy6amK/52YcAKIPlM3a+Fpj35zvRj2TP+e1xFSfk=

internal/protocols/webrtc/incoming_track.go

@@ -20,51 +20,75 @@ const (
 )
 
 var incomingVideoCodecs = []webrtc.RTPCodecParameters{
+	{
+		RTPCodecCapability: webrtc.RTPCodecCapability{
+			MimeType:    webrtc.MimeTypeAV1,
+			ClockRate:   90000,
+			SDPFmtpLine: "profile-id=1",
+		},
+		PayloadType: 96,
+	},
 	{
 		RTPCodecCapability: webrtc.RTPCodecCapability{
 			MimeType:  webrtc.MimeTypeAV1,
 			ClockRate: 90000,
 		},
-		PayloadType: 96,
+		PayloadType: 97,
 	},
 	{
 		RTPCodecCapability: webrtc.RTPCodecCapability{
 			MimeType:    webrtc.MimeTypeVP9,
 			ClockRate:   90000,
-			SDPFmtpLine: "profile-id=0",
+			SDPFmtpLine: "profile-id=3",
 		},
-		PayloadType: 97,
+		PayloadType: 98,
+	},
+	{
+		RTPCodecCapability: webrtc.RTPCodecCapability{
+			MimeType:    webrtc.MimeTypeVP9,
+			ClockRate:   90000,
+			SDPFmtpLine: "profile-id=2",
+		},
+		PayloadType: 99,
 	},
 	{
 		RTPCodecCapability: webrtc.RTPCodecCapability{
 			MimeType:    webrtc.MimeTypeVP9,
 			ClockRate:   90000,
 			SDPFmtpLine: "profile-id=1",
 		},
-		PayloadType: 98,
+		PayloadType: 100,
+	},
+	{
+		RTPCodecCapability: webrtc.RTPCodecCapability{
+			MimeType:    webrtc.MimeTypeVP9,
+			ClockRate:   90000,
+			SDPFmtpLine: "profile-id=0",
+		},
+		PayloadType: 101,
 	},
 	{
 		RTPCodecCapability: webrtc.RTPCodecCapability{
 			MimeType:  webrtc.MimeTypeVP8,
 			ClockRate: 90000,
 		},
-		PayloadType: 99,
+		PayloadType: 102,
 	},
 	{
 		RTPCodecCapability: webrtc.RTPCodecCapability{
 			MimeType:    webrtc.MimeTypeH264,
 			ClockRate:   90000,
 			SDPFmtpLine: "level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42001f",
 		},
-		PayloadType: 100,
+		PayloadType: 103,
 	},
 	{
 		RTPCodecCapability: webrtc.RTPCodecCapability{
 			MimeType:    webrtc.MimeTypeH264,
 			ClockRate:   90000,
 			SDPFmtpLine: "level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f",
 		},
-		PayloadType: 101,
+		PayloadType: 104,
 	},
 }
 
@@ -85,6 +109,22 @@ var incomingAudioCodecs = []webrtc.RTPCodecParameters{
 		},
 		PayloadType: 9,
 	},
+	{
+		RTPCodecCapability: webrtc.RTPCodecCapability{
+			MimeType:  webrtc.MimeTypePCMU,
+			ClockRate: 8000,
+			Channels:  2,
+		},
+		PayloadType: 118,
+	},
+	{
+		RTPCodecCapability: webrtc.RTPCodecCapability{
+			MimeType:  webrtc.MimeTypePCMA,
+			ClockRate: 8000,
+			Channels:  2,
+		},
+		PayloadType: 119,
+	},
 	{
 		RTPCodecCapability: webrtc.RTPCodecCapability{
 			MimeType:  webrtc.MimeTypePCMU,
@@ -166,19 +206,39 @@ func newIncomingTrack(
 		t.format = &format.G722{}
 
 	case strings.ToLower(webrtc.MimeTypePCMU):
+		channels := track.Codec().Channels
+		if channels == 0 {
+			channels = 1
+		}
+
+		payloadType := uint8(0)
+		if channels > 1 {
+			payloadType = 118
+		}
+
 		t.format = &format.G711{
-			PayloadTyp:   0,
+			PayloadTyp:   payloadType,
 			MULaw:        true,
 			SampleRate:   8000,
-			ChannelCount: 1,
+			ChannelCount: int(channels),
 		}
 
 	case strings.ToLower(webrtc.MimeTypePCMA):
+		channels := track.Codec().Channels
+		if channels == 0 {
+			channels = 1
+		}
+
+		payloadType := uint8(8)
+		if channels > 1 {
+			payloadType = 119
+		}
+
 		t.format = &format.G711{
-			PayloadTyp:   8,
+			PayloadTyp:   payloadType,
 			MULaw:        false,
 			SampleRate:   8000,
-			ChannelCount: 1,
+			ChannelCount: int(channels),
 		}
 
 	default:

internal/protocols/webrtc/outgoing_track.go

@@ -33,7 +33,7 @@ func (t *OutgoingTrack) codecParameters() (webrtc.RTPCodecParameters, error) {
 				ClockRate:   90000,
 				SDPFmtpLine: "profile-id=1",
 			},
-			PayloadType: 98,
+			PayloadType: 96,
 		}, nil
 
 	case *format.VP8:
@@ -42,7 +42,7 @@ func (t *OutgoingTrack) codecParameters() (webrtc.RTPCodecParameters, error) {
 				MimeType:  webrtc.MimeTypeVP8,
 				ClockRate: 90000,
 			},
-			PayloadType: 99,
+			PayloadType: 96,
 		}, nil
 
 	case *format.H264:
@@ -52,17 +52,21 @@ func (t *OutgoingTrack) codecParameters() (webrtc.RTPCodecParameters, error) {
 				ClockRate:   90000,
 				SDPFmtpLine: "level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f",
 			},
-			PayloadType: 101,
+			PayloadType: 96,
 		}, nil
 
 	case *format.Opus:
+		if forma.ChannelCount > 2 {
+			return webrtc.RTPCodecParameters{}, fmt.Errorf("unsupported Opus channel count: %d", forma.ChannelCount)
+		}
+
 		return webrtc.RTPCodecParameters{
 			RTPCodecCapability: webrtc.RTPCodecCapability{
 				MimeType:  webrtc.MimeTypeOpus,
 				ClockRate: 48000,
 				Channels:  2,
 			},
-			PayloadType: 111,
+			PayloadType: 96,
 		}, nil
 
 	case *format.G722:
@@ -75,7 +79,22 @@ func (t *OutgoingTrack) codecParameters() (webrtc.RTPCodecParameters, error) {
 		}, nil
 
 	case *format.G711:
+		if forma.SampleRate != 8000 {
+			return webrtc.RTPCodecParameters{}, fmt.Errorf("unsupported G711 sample rate")
+		}
+
 		if forma.MULaw {
+			if forma.ChannelCount != 1 {
+				return webrtc.RTPCodecParameters{
+					RTPCodecCapability: webrtc.RTPCodecCapability{
+						MimeType:  webrtc.MimeTypePCMU,
+						ClockRate: uint32(forma.SampleRate),
+						Channels:  uint16(forma.ChannelCount),
+					},
+					PayloadType: 96,
+				}, nil
+			}
+
 			return webrtc.RTPCodecParameters{
 				RTPCodecCapability: webrtc.RTPCodecCapability{
 					MimeType:  webrtc.MimeTypePCMU,
@@ -85,6 +104,17 @@ func (t *OutgoingTrack) codecParameters() (webrtc.RTPCodecParameters, error) {
 			}, nil
 		}
 
+		if forma.ChannelCount != 1 {
+			return webrtc.RTPCodecParameters{
+				RTPCodecCapability: webrtc.RTPCodecCapability{
+					MimeType:  webrtc.MimeTypePCMA,
+					ClockRate: uint32(forma.SampleRate),
+					Channels:  uint16(forma.ChannelCount),
+				},
+				PayloadType: 96,
+			}, nil
+		}
+
 		return webrtc.RTPCodecParameters{
 			RTPCodecCapability: webrtc.RTPCodecCapability{
 				MimeType:  webrtc.MimeTypePCMA,

internal/servers/webrtc/read_index.html

@@ -107,6 +107,20 @@
 	return ret;
 };
 
+const enableStereoPcmau = (section) => {
+	let lines = section.split('\r\n');
+
+	lines[0] += " 118";
+	lines.splice(lines.length - 1, 0, "a=rtpmap:118 PCMU/8000/2");
+	lines.splice(lines.length - 1, 0, "a=rtcp-fb:118 transport-cc");
+
+	lines[0] += " 119";
+	lines.splice(lines.length - 1, 0, "a=rtpmap:119 PCMA/8000/2");
+	lines.splice(lines.length - 1, 0, "a=rtcp-fb:119 transport-cc");
+
+	return lines.join('\r\n');
+};
+
 const enableStereoOpus = (section) => {
 	let opusPayloadFormat = '';
 	let lines = section.split('\r\n');
@@ -142,7 +156,7 @@
 	for (let i = 0; i < sections.length; i++) {
 		const section = sections[i];
 		if (section.startsWith('audio')) {
-			sections[i] = enableStereoOpus(section);
+			sections[i] = enableStereoPcmau(enableStereoOpus(section));
 		}
 	}
 

internal/servers/webrtc/server_test.go

@@ -423,7 +423,7 @@ func TestServerRead(t *testing.T) {
 		Header: rtp.Header{
 			Version:        2,
 			Marker:         true,
-			PayloadType:    101,
+			PayloadType:    104,
 			SequenceNumber: pkt.SequenceNumber,
 			Timestamp:      pkt.Timestamp,
 			SSRC:           pkt.SSRC,