webrtcbin: Warning: Unknown mline 1, dropping ICE candidates from SDP
I have a following SDP generated by a client (Chromium Nightly):
v=0
o=- 678510979119959053 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE 0 1 2
a=msid-semantic: WMS pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi
m=audio 57248 UDP/TLS/RTP/SAVPF 111 103 104 9 0 8 106 105 13 110 112 113 126
c=IN IP4 172.18.0.1
b=AS:1000
a=rtcp:9 IN IP4 0.0.0.0
a=candidate:1051995033 1 udp 2122260223 172.18.0.1 57248 typ host generation 0 network-id 1 network-cost 50
a=candidate:4162846603 1 udp 2122194687 192.168.243.253 36375 typ host generation 0 network-id 2
a=candidate:545684318 1 udp 2122129151 192.168.88.44 42521 typ host generation 0 network-id 3 network-cost 10
a=ice-ufrag:dUHq
a=ice-pwd:RQIeNLLUdJBf7WAjEhT47IMf
a=ice-options:trickle
a=fingerprint:sha-256 E9:8D:DF:40:DD:CC:99:62:D0:C5:44:24:AC:5F:E6:9B:77:09:F7:9D:AB:22:AB:9A:B8:C3:7D:2F:89:94:09:9E
a=setup:actpass
a=mid:0
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
a=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
a=extmap:5 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
a=extmap:6 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
a=sendrecv
a=msid:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi 2ac49c6a-da84-4ccc-9519-e3fac9d5d31c
a=rtcp-mux
a=rtpmap:111 opus/48000/2
a=rtcp-fb:111 transport-cc
a=fmtp:111 minptime=10;useinbandfec=1
a=rtpmap:103 ISAC/16000
a=rtpmap:104 ISAC/32000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:106 CN/32000
a=rtpmap:105 CN/16000
a=rtpmap:13 CN/8000
a=rtpmap:110 telephone-event/48000
a=rtpmap:112 telephone-event/32000
a=rtpmap:113 telephone-event/16000
a=rtpmap:126 telephone-event/8000
a=ssrc:2092030859 cname:9Hu2ulzcusQe5vAb
a=ssrc:2092030859 msid:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi 2ac49c6a-da84-4ccc-9519-e3fac9d5d31c
a=ssrc:2092030859 mslabel:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi
a=ssrc:2092030859 label:2ac49c6a-da84-4ccc-9519-e3fac9d5d31c
m=video 33261 UDP/TLS/RTP/SAVPF 96 97 98 99 100 101 102 125 127
c=IN IP4 172.18.0.1
b=AS:100000
a=rtcp:9 IN IP4 0.0.0.0
a=candidate:1051995033 1 udp 2122260223 172.18.0.1 33261 typ host generation 0 network-id 1 network-cost 50
a=candidate:4162846603 1 udp 2122194687 192.168.243.253 37363 typ host generation 0 network-id 2
a=candidate:545684318 1 udp 2122129151 192.168.88.44 37910 typ host generation 0 network-id 3 network-cost 10
a=ice-ufrag:dUHq
a=ice-pwd:RQIeNLLUdJBf7WAjEhT47IMf
a=ice-options:trickle
a=fingerprint:sha-256 E9:8D:DF:40:DD:CC:99:62:D0:C5:44:24:AC:5F:E6:9B:77:09:F7:9D:AB:22:AB:9A:B8:C3:7D:2F:89:94:09:9E
a=setup:actpass
a=mid:1
a=extmap:14 urn:ietf:params:rtp-hdrext:toffset
a=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=extmap:13 urn:3gpp:video-orientation
a=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
a=extmap:12 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay
a=extmap:11 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type
a=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing
a=extmap:8 http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07
a=extmap:9 http://www.webrtc.org/experiments/rtp-hdrext/color-space
a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
a=extmap:5 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
a=extmap:6 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
a=sendrecv
a=msid:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi e6eef23e-8f67-4e22-b98f-4ad7349c0587
a=rtcp-mux
a=rtcp-rsize
a=rtpmap:96 VP8/90000
a=rtcp-fb:96 goog-remb
a=rtcp-fb:96 transport-cc
a=rtcp-fb:96 ccm fir
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
a=rtpmap:98 VP9/90000
a=rtcp-fb:98 goog-remb
a=rtcp-fb:98 transport-cc
a=rtcp-fb:98 ccm fir
a=rtcp-fb:98 nack
a=rtcp-fb:98 nack pli
a=fmtp:98 profile-id=0
a=rtpmap:99 rtx/90000
a=fmtp:99 apt=98
a=rtpmap:100 VP9/90000
a=rtcp-fb:100 goog-remb
a=rtcp-fb:100 transport-cc
a=rtcp-fb:100 ccm fir
a=rtcp-fb:100 nack
a=rtcp-fb:100 nack pli
a=fmtp:100 profile-id=2
a=rtpmap:101 rtx/90000
a=fmtp:101 apt=100
a=rtpmap:102 red/90000
a=rtpmap:125 rtx/90000
a=fmtp:125 apt=102
a=rtpmap:127 ulpfec/90000
a=ssrc-group:FID 3500542046 2808507618
a=ssrc:3500542046 cname:9Hu2ulzcusQe5vAb
a=ssrc:3500542046 msid:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi e6eef23e-8f67-4e22-b98f-4ad7349c0587
a=ssrc:3500542046 mslabel:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi
a=ssrc:3500542046 label:e6eef23e-8f67-4e22-b98f-4ad7349c0587
a=ssrc:2808507618 cname:9Hu2ulzcusQe5vAb
a=ssrc:2808507618 msid:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi e6eef23e-8f67-4e22-b98f-4ad7349c0587
a=ssrc:2808507618 mslabel:pfQqB0MHvtm8LEKUICZOCqiuudWbEzcQSgSi
a=ssrc:2808507618 label:e6eef23e-8f67-4e22-b98f-4ad7349c0587
m=application 55465 UDP/DTLS/SCTP webrtc-datachannel
c=IN IP4 172.18.0.1
a=candidate:1051995033 1 udp 2122260223 172.18.0.1 55465 typ host generation 0 network-id 1 network-cost 50
a=candidate:4162846603 1 udp 2122194687 192.168.243.253 55424 typ host generation 0 network-id 2
a=candidate:545684318 1 udp 2122129151 192.168.88.44 55460 typ host generation 0 network-id 3 network-cost 10
a=ice-ufrag:dUHq
a=ice-pwd:RQIeNLLUdJBf7WAjEhT47IMf
a=ice-options:trickle
a=fingerprint:sha-256 E9:8D:DF:40:DD:CC:99:62:D0:C5:44:24:AC:5F:E6:9B:77:09:F7:9D:AB:22:AB:9A:B8:C3:7D:2F:89:94:09:9E
a=setup:actpass
a=mid:2
a=sctp-port:5000
Surprisingly, I've got these messages in the log:
0:00:04.753809450 19916 0x7f20f809ae80 WARN webrtcbin gstwebrtcbin.c:3513:_add_ice_candidates_from_sdp:<webrtcbin0> Unknown mline 1, dropping ICE candidates from SDP
0:00:04.753819176 19916 0x7f20f809ae80 WARN webrtcbin gstwebrtcbin.c:3513:_add_ice_candidates_from_sdp:<webrtcbin0> Unknown mline 2, dropping ICE candidates from SDP
Which doesn't make a lot of sense since media 1
and 2
are present in the SDP. The only manual tweaks done to the SDP generated by the browser are b=AS:*
lines being added.
Looking at the code it feels like it is related to the order of a=
elements in SDP.