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

Iñaki Baz Castillo <ibc@aliax.net> Thu, 07 March 2013 21:15 UTC

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From: =?UTF-8?Q?I=C3=B1aki_Baz_Castillo?= <ibc@aliax.net>
Date: Thu, 7 Mar 2013 22:14:48 +0100
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To: Peter Thatcher <pthatcher@google.com>
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Cc: "<rtcweb@ietf.org>" <rtcweb@ietf.org>
Subject: Re: [rtcweb] Proposed Plan for Usage of SDP and RTP - Lower level API minus SDP
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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>