Re: [rtcweb] How to get a diff between the remote SDP in an established session and a new received SDP offer

[Martin Thomson <[e-mail]>]

On 6 July 2012 00:33, Iñaki Baz Castillo <[e-mail]> wrote:
> I hope that raw parsing of the received SDP is not needed for achieving this :)

I'm surprised that you think that.

I believe that the subject is one of the open issues, though I believe
that the current discussion was heading toward the conclusion that
calling set<X>Description() on a PeerConnection was the blessed method
for determining what streams are present in an offer or answer.

Therefore, the process is something like...

# Take existing session, look at the attached streams (and their tracks).
# Take new offer, create new PeerConnection, attach the same local
streams, call pc.setRemoteDescription(OFFER, sdpOffer), examine the
resulting attached streams (and their tracks).
# Discard the new PeerConnection.

Of course, this is highly likely to fail because the resources
necessary to create and configure the second PeerConnection are likely
taken by the first.  So your best bet is to scrounge through the SDP.
But SDP is awesome, so it's OK.

--Martin