W3C home > Mailing lists > Public > public-webrtc@w3.org > February 2014

Re: Panic between createOffer() and setLocalDescription()

From: Tim Panton new <thp@westhawk.co.uk>
Date: Thu, 20 Feb 2014 17:07:49 +0000
Cc: Harald Alvestrand <harald@alvestrand.no>, public-webrtc <public-webrtc@w3.org>
Message-Id: <5909B0AA-AB51-4894-9795-77B590215147@westhawk.co.uk>
To: piranna@gmail.com

On 20 Feb 2014, at 09:44, piranna@gmail.com wrote:

>> I'm not sure that's a compelling reason to separate the two, but it's a
>> possible reason, even in the absence of SDP modification.
>> 
> I'm not saying to remove setLocalDescription(), I'm only saying that
> for most use cases is redundant to call to
> createOffer()/createAnswer() and inmediately to setLocalDescription(),
> so I'll change the spec to do the call implicitly and if some changes
> are required, let the user to do the call explicitly, overwritting
> this way the content of the local description with its custom one.
> This will make easier to new comers what's the call flow:
> 
> createOffer() -> send()
> onmessage -> setRemoteDescription()
> createAnswer() -> send()
> onmessage -> setRemoteDescription()
> 
> Honestly, if you need to call to setLocalDescription() with a modified
> SDP, you are not in "WebRTC 101" anymore... Why complicate it?

Except that WebRTC 101 - the example apprtc app does munge the SDP before calling
setLocal.

function setLocalAndSendMessage(sessionDescription) {
  sessionDescription.sdp = maybePreferAudioReceiveCodec(sessionDescription.sdp);
  pc.setLocalDescription(sessionDescription,
       onSetSessionDescriptionSuccess, onSetSessionDescriptionError);
  sendMessage(sessionDescription);
}

So even in the simplest cases you end up needing to intercept.

T.
Received on Thursday, 20 February 2014 17:08:39 UTC

This archive was generated by hypermail 2.3.1 : Monday, 23 October 2017 15:19:38 UTC