Take direction into account when parsing RTP extensions

[atoppi]

Your environment.

• Version: pion v3.1.0, latest example

What did you do?

I've published the janus video-room client to my local janus master instance

What did you expect?

AV works, no weird output on the janus console

What happened?

AV works BUT janus continuously prints warning about an unknown SSRC

Dropping RTCP packet with unknown SSRC (2596996162)

Wireshark investigations lead to unexpected TWCC reports being sent from the pion client

I guess those feedbacks are unexpected since janus is sending a SDP answer with recv-only direction.

[atoppi]

even by using a sendonly connection from pion

peerConnection.AddTransceiverFromTrack(vp8Track, webrtc.RtpTransceiverInit{
		Direction: webrtc.RTPTransceiverDirectionSendonly,
	})

the client is still generating dummy twcc feedbacks

[Sean-Der]

Nice catch! Thanks for reporting @atoppi

I don't think we take direction into account at all when parsing extensions. I will fix that :)