- From: Peter Thatcher <pthatcher@google.com>
- Date: Mon, 31 Aug 2015 15:30:24 -0700
- To: Harald Alvestrand <harald@alvestrand.no>
- Cc: "public-webrtc@w3.org" <public-webrtc@w3.org>
- Message-ID: <CAJrXDUG6rMOBEf+Vt1-ybDB6p4RWYzYyRSp-UEV1poBxg5qwtA@mail.gmail.com>
On Sun, Aug 30, 2015 at 2:14 AM, Harald Alvestrand <harald@alvestrand.no> wrote: > Den 29. aug. 2015 06:44, skrev Peter Thatcher: > > > > > > On Fri, Aug 28, 2015 at 2:20 PM, Harald Alvestrand <harald@alvestrand.no > > <mailto:harald@alvestrand.no>> wrote: > > > > Perhaps (freely fantasizing) our model should be that there always > > exist as many RTPSenders and RTPReceivers as the number of m-lines > > in the next SDP createOffer will create > > > > > > I think that makes a lot of sense. > > > > > > > > , and that what happens when you do addTrack is either that you bind > > to an existing sender or add a new one (causing negotiationneded)? > > > > > > > > I think addTrack would always create a new RtpSender, but that may bind > > to an existing m-line. > > If the existence of an m-line implies that an RtpSender already exists > for it, addTrack creating a new RTPsender would imply that you either > replace the old one or that you end up with two RtpSenders referencing > the same m-line. > There are two ways two think about this on the answer side: Option A; setRemote Description(offer) does not create an RtpSender, because it's possible for an RtpReceiver to be "alone" without a matching RtpSender. In this case, addTrack would add a new RtpSender that would have the same MID as the RtpReceiver. Option B: setRemoteDescription(offer) creates an RtpSender, because there must be an RtpSender for each RtpReceiver. In this case, addTrack would not add a new RtpSender, it would just "activate" the sender. Both could work, and have slightly different pros and cons. > Since the latter is breaking the model we just proposed, I assume that > you mean the former - but why? > I was suggesting Option A. I had not thought of Option B until you wrote your email. But now I see that both are valid options to take. But we need to pick one. The current spec is ore like Option A.
Received on Monday, 31 August 2015 22:31:31 UTC