Re: [rtcweb] Proposed Plan for Usage of SDP and RTP - Lower level API minus SDP

Peter Thatcher <pthatcher@google.com> Thu, 07 March 2013 21:17 UTC

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From: Peter Thatcher <pthatcher@google.com>
Date: Thu, 7 Mar 2013 13:17:15 -0800
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Subject: Re: [rtcweb] Proposed Plan for Usage of SDP and RTP - Lower level API minus SDP
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That's a very good point.  I think any replacement SessionDescription
ought to have a clear "update" mechanism built in.

On Thu, Mar 7, 2013 at 1:14 PM, Iñaki Baz Castillo <ibc@aliax.net> wrote:
> 2013/3/7 Peter Thatcher <pthatcher@google.com>:
>> Having a JSON-based SessionDescription that's a 1:1 mapping to SDP
>> semantically seems like a bad idea to me.  We want something better
>> than SDP, not just a different syntax for SDP.  Trying to map all of
>> SDP would be a near-impossible task anyway.
>
> An SDP is so "flexible" that it can include:
>
> - multiple m video lines.
> - with multiple SSRC each one.
> - may be bundle for audio and video.
> - may be separate ICE candidates for audio and each different "m" video.
> - and so on. Too much "flexibility".
>
> It's more than difficut to expect that a JS custom code can consider
> all those possibilities. That's IMHO the main problem of SDP and not
> so much the SDP format itself (which can be managed via a good JS
> API).
>
> And the worst of SDP IMGO: having to send the *entire* SDP when any
> minimal change is done, so the receive must do magic to realize of the
> exact change without "resetting" all.
>
>
> --
> Iñaki Baz Castillo
> <ibc@aliax.net>