W3C home > Mailing lists > Public > public-webrtc@w3.org > July 2013

Re: do we want success and failure callbacks on addStream?

From: Eric Rescorla <ekr@rtfm.com>
Date: Wed, 24 Jul 2013 07:24:46 -0700
Message-ID: <CABcZeBMHVAxiCnANoykGou=vLnBbMnF3TPBuEVTCQXFQLSXY=w@mail.gmail.com>
To: Iņaki Baz Castillo <ibc@aliax.net>
Cc: "Cullen Jennings (fluffy)" <fluffy@cisco.com>, "piranna@gmail.com" <piranna@gmail.com>, Jim Barnett <Jim.Barnett@genesyslab.com>, "public-webrtc@w3.org" <public-webrtc@w3.org>
On Wed, Jul 24, 2013 at 2:27 AM, Iņaki Baz Castillo <ibc@aliax.net> wrote:

> 2013/7/24 Cullen Jennings (fluffy) <fluffy@cisco.com>:
> > I think we should use a callback on addStream
> Which information would such a callback provide? Would it be called
> with an "error" argument if the remote rejects ALL THE TRACKS of the
> stream with "port 0" in their "m" line?

I think you're misunderstanding the context in which an error would
be fired. It's not going to be in response to the other side rejecting
the offer but in response to the PC not being able to construct a new
offer which would reflect the stream. Recall that the effect of invoking
addStream() is to call .onrenegotiationneeded() not to actually
exchange any signaling messages.

To give an example, consider what happens if you add a closed
stream. This isn't ever going to work, so there needs to be an
error reported here, even though we have no idea of the
other side's capabilities.


Would it be called with
> "error" argument if JUST some of the tracks of the stream are
> rejected? what about if an invalid SDP is returned? what about if SIP
> is signaed and a 488 replied? What about if the remote accepts all the
> tracks in the stream but set "a=inactive" for SOME of them?
> Since we CANNOT inspect the SDP at JS level for matching there our
> local streams and track, it is just impossible to realize of what
> happened in the remote side upon receipt of our updated offer.
> And again: this means that I add a video track, signal it via
> re-INVITE to the peer, the peer replies with "a=inactive" or port 0
> for such a track and I do not know whether the remote wants to receive
> my video or not. Yes, it could signal me (via custom sig protocol)
> something like "I do not want your video" but that is not feasible if
> we play SIP since such a signaling is done via SDP.
> --
> Iņaki Baz Castillo
> <ibc@aliax.net>
Received on Wednesday, 24 July 2013 14:25:58 UTC

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