Re: [rtcweb] How to get a diff between the remote SDP in an established session and a new received SDP offer
Stefan Hakansson LK <stefan.lk.hakansson@ericsson.com> Tue, 10 July 2012 08:11 UTC
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Date: Tue, 10 Jul 2012 10:11:53 +0200
From: Stefan Hakansson LK <stefan.lk.hakansson@ericsson.com>
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Subject: Re: [rtcweb] How to get a diff between the remote SDP in an established session and a new received SDP offer
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On 07/06/2012 09:33 AM, Iñaki Baz Castillo wrote:
> Hi, I would really appreciate some explanation about this subject.
> Basically the aim of my question is to imitate the behavior of
> existing chat+audio+video clients in which the session is initially
> started with just audio, and video is added later (by asking for user
> consent).
>
> I hope that raw parsing of the received SDP is not needed for achieving this :)
The API is designed around MediaStreams and MediaStream tracks. So, for
the app receiving a MediaStream that travels from another app using a
PeerConnection, any change would (if you do not do SDP parsing!) be
shown by events such as "addstream"/"removestream" (for PeerConnection)
"addtrack"/"removetrack" (for a MediaStream) and "mute"/"unmute" (for a
MediaStream track). Could not these events be used to trigger change at
the receiving app (e.g. if the incoming video track changes to "unmute"
the outgoing one is enabled in response)?
In addition, the app's can signal anything they would like to using
proprietary signaling ("I would like to enable video, OK?").
Br,
Stefan
>
> Regards.
>
>
> 2012/7/4 Iñaki Baz Castillo <ibc@aliax.net>:
>> Hi, let's assume I have an established audio session. Later the remote
>> sends me a new SDP offer (let's say a SIP re-INVITE) and I want to
>> analyze what is new in the new SDP (in order to ask the user for
>> consent). So for example when the new SDP arrives I need to know
>> whether it contains audio and video or whatever.
>>
>> With the current JSEP API I see no way. The only I can do with the new
>> received SDP is:
>>
>> pc.setRemoteDescription(SDP_OFFER, REMOTE_SDP_TEXT)
>>
>> but this would alter my multimedia session before I can ask my user
>> for consent. Do I miss something?
>>
>> And I would also like to know whether the received SDP contains
>> dissabled streams (i.e. a video stream with port 0) before accepting
>> it. Basically I want a mechanism for getting a diff between the
>> existing remote SDP and the new received one.
>>
>> --
>> Iñaki Baz Castillo
>> <ibc@aliax.net>
>
>
>
- [rtcweb] How to get a diff between the remote SDP… Iñaki Baz Castillo
- Re: [rtcweb] How to get a diff between the remote… Iñaki Baz Castillo
- Re: [rtcweb] How to get a diff between the remote… Martin Thomson
- Re: [rtcweb] How to get a diff between the remote… Stefan Hakansson LK
- Re: [rtcweb] How to get a diff between the remote… Iñaki Baz Castillo
- Re: [rtcweb] How to get a diff between the remote… Stefan Hakansson LK
- Re: [rtcweb] How to get a diff between the remote… Eric Rescorla