Re: [rtcweb] Proposed Plan for Usage of SDP and RTP - Lower level API minus SDP
Peter Thatcher <pthatcher@google.com> Thu, 07 March 2013 20:56 UTC
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From: Peter Thatcher <pthatcher@google.com>
Date: Thu, 07 Mar 2013 12:56:05 -0800
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To: Eric Rescorla <ekr@rtfm.com>
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Subject: Re: [rtcweb] Proposed Plan for Usage of SDP and RTP - Lower level API minus SDP
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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. I think you're combining two separate questions: a. Should the Browser<->JS API have SessionDescriptions at all, or should it have just low-level methods? b. Should the SessionDescription be representable as SDP or as something else or both? So far, we have two camps that combine the two questions: Pro-SDP camp: methods=createOffer/setLocal/setRemote and format=SDP Anti-SDP camp: methods=low-level methods and format=none I'm suggesting that there might value in a third possibility: Compromise: methods=createOffer/setLocal/setRemote and format=JSON The Pro-SDP camp will tell the Anti-SDP camp, "don't blow up the world". The Anti-SDP camp will tell the Pro-SDP camp, "SDP is a horrible API surface". I think they are both right. And I hope that an alternative format for a SessionDescription would be a sufficiently good compromise. I don't think of it as a fork of SDP, but rather as a much better way to describe sessions than SDP. I've personally worked with 6 different kinds of session descriptions (SDP, Jingle, libjingle internals, and a few different Google internal representations), and SDP is by far the worst, not just in syntax but in semantics also. I think a JSON one could be much better syntax and semantics, without quite "blowing up the world". At least, that's my hope. On Thu, Mar 7, 2013 at 10:45 AM, Eric Rescorla <ekr@rtfm.com> wrote: > > > On Thu, Mar 7, 2013 at 10:33 AM, Peter Thatcher <pthatcher@google.com> > wrote: >> >> A question for all of you in the "please don't make us use SDP as an >> API forever" crowd (and I include myself): Would it be acceptable to >> you to have an intermediate step where we keep createOffeer, >> setRemoteDescription and setLocalDescription as-is, but allow a JSON >> argument? It seems to be that such a thing could provide all the same >> low-level of control as any other setup of methods, but may be much >> more likely to be accepted by the group as a whole. And, it would >> still be a lot more pleasant for application developers, and leave >> more flexibility for a future where low-level methods might be added. >> >> As both an application developer and a browser implementor, I think a >> good SessionDescription JSON format would be easy to implement, >> pleasant to use, a small incremental step from what we currently have, >> and would relieve the standards body of so much fighting over what the >> SDP should look like. >> >> I know it wouldn't be exactly what you're looking for, but I think it >> would be achievable and much better than what we have. > > > II don't understand how this changes anything meaningful. The point > of using SDP isn't the crufty line-based encoding, it's being committed > to the SDP offer/answer semantics. So, when you talk about having > JSON, you're talking about one of two things: > > 1. Having a format which is semantically equivalent to SDP. > 2. Having a format which is semantically distinct (or perhaps a superset) > of SDP. > > In case 1, I don't see what this bought you, other than programming > convenience. It's not like it would be difficult to build code to > mechanically > dissect the SDP encoding. > > In case 2, you have forked SDP, and largely obviated the point of > using SDP in the first place. > > -Ekr > >
- [rtcweb] Proposed Plan for Usage of SDP and RTP -… Robin Raymond
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Hadriel Kaplan
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Martin Thomson
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Mary Barnes
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Eric Rescorla
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Roman Shpount
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Eric Rescorla
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Mary Barnes
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Erik Lagerway
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Silvia Pfeiffer
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Iñaki Baz Castillo
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Iñaki Baz Castillo
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Silvia Pfeiffer
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Silvia Pfeiffer
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Iñaki Baz Castillo
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Roman Shpount
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Matthew Kaufman
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Iñaki Baz Castillo
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Silvia Pfeiffer
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Matthew Kaufman
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Silvia Pfeiffer
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Timothy B. Terriberry
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Silvia Pfeiffer
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Timothy B. Terriberry
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Harald Alvestrand
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Stefan Håkansson LK
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Robin Raymond
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Stefan Håkansson LK
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Stefan Håkansson LK
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Stefan Håkansson LK
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Peter Thatcher
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Matthew Kaufman (SKYPE)
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Matthew Kaufman (SKYPE)
- [rtcweb] Division of labor (Re: Proposed Plan for… Harald Alvestrand
- Re: [rtcweb] Division of labor (Re: Proposed Plan… Matthew Kaufman
- Re: [rtcweb] Proposed Plan for Usage of SDP and R… Justin Uberti
- [rtcweb] Separating stream manipulation from the … Harald Alvestrand
- Re: [rtcweb] Separating stream manipulation from … Peter Thatcher
- Re: [rtcweb] Separating stream manipulation from … Stefan Håkansson LK
- Re: [rtcweb] Separating stream manipulation from … Harald Alvestrand
- Re: [rtcweb] Separating stream manipulation from … Ted Hardie
- Re: [rtcweb] Separating stream manipulation from … Martin Thomson
- Re: [rtcweb] Separating stream manipulation from … Silvia Pfeiffer
- Re: [rtcweb] Separating stream manipulation from … Suhas Nandakumar
- Re: [rtcweb] Separating stream manipulation from … Silvia Pfeiffer
- Re: [rtcweb] Separating stream manipulation from … Harald Alvestrand
- Re: [rtcweb] Separating stream manipulation from … Dale R. Worley