Give distinct names for audio- and video- receive-output-bins

[trollfred]

Name collision freaks gstreamer out when using audio+video BUNDLE

[Rugvip]

What changes did you make to cause that naming conflict? We don't support bundling atm, but it's still a good thing to fix this since it's possible to edit the SDP.

Adding a media type suffix to the bin isn't enough to solve the problem though, since it's possible to have multiple audio and video streams.

[trollfred]

I just tried to bundle audio + video, so there was collision on adding second stream. Giving distinct names solved problem for me, but yes, it isn't enough if there are multiple audio or video streams. I suggest adding stream id to name in order solve all possible conflicts, I can try to do it if it seems ok to you.

[Rugvip]

What user agents and platforms did you use to test this?

Bundling isn't currently supported, and if implemented it wouldn't be on the session level, since each OwrMediaSession only has a single send source. That said we still want to avoid conflicts when receiving unexpected RTP stream, but I'm not sure if the stream should be ignored or handled in some other way. @pererikb @adam-be ?

[superdump]

To do it with the current API you would want to have the incoming packets split into their respective sessions before being fed into rtpbin and then merge the outgoing rtp/rtcp into one stream appropriately. Alternatively I guess you could have some SSRC to session mapping in rtpbin for the bundle case

[superdump]

If we consider a session to be an m= section that is.

[stefhak]

The latest development calls for using the MID header RTP field in combination with the a=MID: SDP attribute to sort the different incoming SSRCs into the right MediaStreamTrack. That is because each m= section can have several active SSRCs associated to it (e.g. to carry FEC data). So we're really looking for a MID to m= section mapping.
I can create a patch for adding a=MID to the SDP, will perhaps need some help in making sure the RTP-stack adds it to each outgoing RTP packet.