Re: [rtcweb] Making progress on the signaling discussion (NB: Action items enclosed!)

"Timothy B. Terriberry" <tterriberry@mozilla.com> Wed, 12 October 2011 13:59 UTC

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Date: Wed, 12 Oct 2011 06:59:36 -0700
From: "Timothy B. Terriberry" <tterriberry@mozilla.com>
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Subject: Re: [rtcweb] Making progress on the signaling discussion (NB: Action items enclosed!)
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> Lets assume we use a subset/variant of SDP as a codec capability
> description 'language' - (i.e. we won't be using the parts that relate
> to network properties).

I've seen this proposed a couple of times now, and I would like to point 
out that this is a terrible assumption. There are many things that one 
might want to control about a codec that will never show up in SDP, 
because they don't require explicit negotiation between sender and 
receiver (e.g., the sender gets to make a unilateral decision and the 
receiver simply deals with it... like, say, the amount of time a video 
encoder is willing to spend doing a motion search, etc.).

Limiting yourself to the parameters that do happen to show up in SDP is 
a pretty poor half-solution, if you really do think you need a low-level 
API of this kind, and may not have obvious extension points to get to a 
full solution.