At present, I have successfully created a video channel using webrtcbin, and the captured video can be sent to the receiver and played after encoding. But the current video has serious quality issues, especially when the network is in poor condition. I knew I needed to use proper flow control techniques to control the bit rate of the encoding, as well as some FEC or retransmission methods to improve the video quality, but I didn’t find any way on the web to incorporate these features into the webrtcbin component.Any ideas on how to add components like rtpgccbwe, rtpulpfecenc to webrtcbin and make their functionality work would be appreciated!
I learned that the webrtcbin plugin submitted a fix a few days ago:
webrtcbin: fix regression with missing RTP header extensions in Answer SDP
[type or paste code here](https://gitlab.freedesktop.org/gstreamer/gstreamer/-/commit/77faf0a16319738159566c22cc68047baec330ce)
I then compiled the latest gstreamer code, but I found that the correct rtp header extensions message was still not generated automatically in answer sdp,The following is my offer sdp and answer sdp:
(1)offer sip
v=0
o=- 6271000081781861256 0 IN IP4 0.0.0.0
s=-
t=0 0
a=ice-options:trickle
a=group:BUNDLE video0 application1
m=video 9 UDP/TLS/RTP/SAVPF 96
c=IN IP4 0.0.0.0
a=setup:actpass
a=ice-ufrag:zgJz5/lIyCevphsb2tlZSZRydo98zcLE
a=ice-pwd:pHJJpUIvtjWUAas8wRWUgXOnP6ZNVG1B
a=rtcp-mux
a=rtcp-rsize
a=sendrecv
a=rtpmap:96 H265/90000
a=rtcp-fb:96 nack pli
a=rtcp-fb:96 ccm fir
a=rtcp-fb:96 transport-cc
a=framerate:60
a=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
a=ssrc:442425399 msid:user3187992983@host-86797cff webrtctransceiver1
a=ssrc:442425399 cname:user3187992983@host-86797cff
a=mid:video0
a=fingerprint:sha-256 33:ED:C1:2B:F3:98:3C:39:8D:00:55:71:E3:55:1D:CC:7F:D1:BF:4E:D5:A9:0F:11:0F:BB:22:F7:2C:83:55:CD
a=rtcp-mux-only
m=application 0 UDP/DTLS/SCTP webrtc-datachannel
c=IN IP4 0.0.0.0
a=setup:actpass
a=ice-ufrag:zgJz5/lIyCevphsb2tlZSZRydo98zcLE
a=ice-pwd:pHJJpUIvtjWUAas8wRWUgXOnP6ZNVG1B
a=bundle-only
a=mid:application1
a=sctp-port:5000
a=fingerprint:sha-256 33:ED:C1:2B:F3:98:3C:39:8D:00:55:71:E3:55:1D:CC:7F:D1:BF:4E:D5:A9:0F:11:0F:BB:22:F7:2C:83:55:CD
(2)answer sdp
v=0
o=- 6271000081781861256 0 IN IP4 0.0.0.0
s=-
t=0 0
a=ice-options:trickle
a=group:BUNDLE video0 application1
m=video 9 UDP/TLS/RTP/SAVPF 96
c=IN IP4 0.0.0.0
a=ice-ufrag:3sESPOb3X591aE8P+b9UI0Ph6JKTBUz9
a=ice-pwd:1RBguhvLKoDR5aUewQKV5o7C66Onpad+
a=rtcp-mux
a=mid:video0
a=setup:active
a=rtpmap:96 H265/90000
a=rtcp-fb:96 nack pli
a=rtcp-fb:96 ccm fir
a=rtcp-fb:96 transport-cc
a=recvonly
a=fingerprint:sha-256 4C:42:78:1D:AD:C2:62:0B:3D:9C:4F:B7:30:44:1A:6A:4E:70:F9:85:02:F7:17:DA:2F:E7:0E:10:FA:B4:BF:31
m=application 9 UDP/DTLS/SCTP webrtc-datachannel
c=IN IP4 0.0.0.0
a=ice-ufrag:3sESPOb3X591aE8P+b9UI0Ph6JKTBUz9
a=ice-pwd:1RBguhvLKoDR5aUewQKV5o7C66Onpad+
a=mid:application1
a=setup:active
a=sctp-port:5000
a=fingerprint:sha-256 4C:42:78:1D:AD:C2:62:0B:3D:9C:4F:B7:30:44:1A:6A:4E:70:F9:85:02:F7:17:DA:2F:E7:0E:10:FA:B4:BF:31
Is it because sdp did not negotiate correctly that twcc has no data? How should I negotiate twcc extension correctly?