Re: [rtcweb] Proposal for a JS API for NoPlan (adding multiple sources without encoding them in SDP)

Iñaki Baz Castillo <> Wed, 19 June 2013 17:21 UTC

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Date: Wed, 19 Jun 2013 19:20:57 +0200
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To: Peter Thatcher <>
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Subject: Re: [rtcweb] Proposal for a JS API for NoPlan (adding multiple sources without encoding them in SDP)
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2013/6/19 Peter Thatcher <>

> You don't need a lower level API.  SDP munging can get you what you need.  But what you want is to not have to do SDP munging.
> My proposal is to add two methods to PeerConnection that, if optionally used by JS, will give you what you want for media streams: the ability to control what is sent and received without SDP munging.  It does not, however, relieve you from SDP munging on the transport side.  But as I've pointed out, that's limited to about 10 lines of SDP, so at least it's much less SDP munging.  Later, once could consider more simple additions that reduce the need for SDP munging further.

You base your proposal on the fact that SDP is here forever and must
be used in WebRTC, and then propose some new API methods along with
*lot* of SDP JS parsing/mangling/hackery to mitigate the API

While it could be the best we have for now, IMHO it is still a hack or
workaround to just circumvent the real problem and the real

Things can be done much better if we remove SDP from the equation.

Best regards.

Iñaki Baz Castillo