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Re: SDP wrapper? Object-oriented API?

From: cowwoc <cowwoc@bbs.darktech.org>
Date: Wed, 19 Jun 2013 09:24:16 -0400
Message-ID: <51C1B100.6010008@bbs.darktech.org>
To: "piranna@gmail.com" <piranna@gmail.com>
CC: Frédéric Luart <frederic.luart@apizee.com>, public-webrtc <public-webrtc@w3.org>, Silvia Pfeiffer <silviapfeiffer1@gmail.com>

     To recap, we have the following use-cases for mutating the SDP:

  * Browser interop (keeping this on the list because I anticipate the
    need as IE, Safari and Opera come on board)
  * Prioritizing audio/video streams
  * Bandwidth limits
  * Codec limits

     Please keep these coming. We need to understand all use-cases in 
order to formulate an API.

Gili

On 19/06/2013 5:41 AM, piranna@gmail.com wrote:
>
> User requested min&max bandwidth usage 
> (https://groups.google.com/forum/m/#!topic/discuss-webrtc/yPc0DDW-4Fs 
> <https://groups.google.com/forum/m/#%21topic/discuss-webrtc/yPc0DDW-4Fs>)
>
> El 19/06/2013 10:28, "Frédéric Luart" <frederic.luart@apizee.com 
> <mailto:frederic.luart@apizee.com>> escribió:
>
>     We have this possibilities for now on our API concerning SDP :
>
>     - Set Opus as preferred codec
>     - Use RTP instead of SRTP
>
>     And we plan to add bandwidth limitation and codecs restriction.
>
>     We also have the possibility to control media routing mode :
>     http://www.apirtc.com/media-routing-optimisation/
>
>     Fred
>
>     -----Original Message-----
>     From: Silvia Pfeiffer [mailto:silviapfeiffer1@gmail.com
>     <mailto:silviapfeiffer1@gmail.com>]
>     Sent: mercredi 19 juin 2013 04:26
>     To: piranna@gmail.com <mailto:piranna@gmail.com>
>     Cc: cowwoc; public-webrtc
>     Subject: Re: SDP wrapper? Object-oriented API?
>
>     I've seen a hack to limit bandwidth use, which includes a b=AS:
>     inclusion in the m= line.
>
>     Silvia.
>
>     On Wed, Jun 19, 2013 at 8:35 AM, piranna@gmail.com
>     <mailto:piranna@gmail.com> <piranna@gmail.com
>     <mailto:piranna@gmail.com>>
>     wrote:
>     > Chrome-Firefox interoperation will be fixed without hacks in
>     some weeks,
>     so
>     > it's not a valid use case. Giving higher priority to Opus over
>     others it
>     is,
>     > but could also be done with a higher priority API.
>     >
>     > El 19/06/2013 00:18, "cowwoc" <cowwoc@bbs.darktech.org
>     <mailto:cowwoc@bbs.darktech.org>> escribió:
>     >
>     >>
>     >>     Sure. If you look at apprtc (the reference WebRTC
>     application) you
>     >> will notice they manipulate the SDP to improve Chrome-Firefox
>     interop and
>     >> give Opus a higher priority than other audio streams.
>     >>
>     >>     That's basic stuff. I'm sure others have more use-cases.
>     >>
>     >> Gili
>     >>
>     >> On 18/06/2013 4:10 PM, Frédéric Luart wrote:
>     >>
>     >> Hi Gili,
>     >>
>     >>
>     >>
>     >> Do you already have some use cases where you need SDP
>     manipulation ?
>     >>
>     >>
>     >>
>     >> Fred
>     >>
>     >>
>     >>
>     >> From: cowwoc [mailto:cowwoc@bbs.darktech.org
>     <mailto:cowwoc@bbs.darktech.org>]
>     >> Sent: lundi 17 juin 2013 17:05
>     >> To: public-webrtc@w3.org <mailto:public-webrtc@w3.org>
>     >> Subject: Re: SDP wrapper? Object-oriented API?
>     >>
>     >>
>     >>
>     >> Hi Fred,
>     >>
>     >>     A good first step but I'm not looking for an API that wraps
>     all of
>     >> WebRTC. I just want the SDP portion wrapped.
>     >>
>     >> Thanks,
>     >> Gili
>     >>
>     >> On 17/06/2013 8:51 AM, Frédéric Luart wrote:
>     >>
>     >> Hello Ken,
>     >>
>     >>
>     >>
>     >> We started to develop a WebRTC JavaScript library which is
>     available at
>     >> www.apirtc.com <http://www.apirtc.com>
>     >>
>     >> We are experts on VoIP and one of our objectives in the
>     development of
>     >> this library is to bring our expertise to Web developers and solve
>     specific
>     >> VoIP issues
>     >>
>     >> We plan to add this “SDP manipulation” feature on our API so
>     let us know
>     >> if we can help on this subject
>     >>
>     >>
>     >>
>     >> Fred
>     >>
>     >>
>     >>
>     >> From: Ken Smith [mailto:smithkl42@gmail.com
>     <mailto:smithkl42@gmail.com>]
>     >> Sent: samedi 15 juin 2013 07:14
>     >> To: cowwoc
>     >> Cc: Suhas Nandakumar (snandaku); public-webrtc@w3.org
>     <mailto:public-webrtc@w3.org>
>     >> Subject: Re: SDP wrapper? Object-oriented API?
>     >>
>     >>
>     >>
>     >> I would believe that SDP is a mere "implementation detail" if
>     it weren't
>     >> for the fact that over on the webrtc-discuss mailing list,
>     maybe half the
>     >> discussions involve how to tweak the SDP to get it to
>     interoperate with
>     some
>     >> gateway or other.
>     >>
>     >>
>     >>
>     >> It's quite plausible to me that because of backwards compatibility
>     issues,
>     >> dealing with SDP directly is going to remain a critical feature of
>     getting
>     >> WebRTC to work with legacy systems. But among other things,
>     that also
>     leads
>     >> me to believe that the industry has suffered a collective
>     failure of
>     >> imagination. SDP is a horrible API, and somebody, somewhere need to
>     figure
>     >> out a better way of getting these systems to interoperate without
>     arbitrary
>     >> edits to of opaque text files.
>     >>
>     >>
>     >>
>     >> That's probably beyond the scope of WebRTC, but I'd appreciate
>     it if
>     >> everyone involved in designing these API's took this as an
>     important data
>     >> point. Folks like myself who want to use WebRTC but who aren't
>     experts in
>     >> VOIP quite justifiably hate everything about SDP and everything
>     it stands
>     >> for. It's a significant problem in desperate need of a real
>     solution.
>     >>
>     >>
>     >>
>     >> Ken
>     >>
>     >>
>     >>
>     >> On Fri, Jun 14, 2013 at 8:58 PM, cowwoc
>     <cowwoc@bbs.darktech.org <mailto:cowwoc@bbs.darktech.org>> wrote:
>     >>
>     >>
>     >>     An object wrapper would be nice but it wasn't really the
>     point I was
>     >> trying to make.
>     >>
>     >>     My point is that if SDP really is an implementation detail
>     then the
>     >> specification must ensure that we can swap it out for something
>     else in
>     the
>     >> future without breaking backwards compatibility. To me, that
>     begins by
>     >> specifying that the SDP argument is an opaque token. WebRTC 1.0
>     might use
>     >> SDP while WebRTC 2.0 might use some other format.
>     >>
>     >> Gili
>     >>
>     >>
>     >>
>     >> On 14/06/2013 11:47 PM, Suhas Nandakumar (snandaku) wrote:
>     >>
>     >> My 2 cents ....
>     >>
>     >> I personally dont feel why would one want to modify SDP
>     frequently than
>     >> supporting few special cases. Also once the APIs, SDP Usages and
>     constraints
>     >> are finalized, i envision there will be much lesser need to
>     modify SDP by
>     >> hand.
>     >>
>     >> Needing to have a object wrapper is fine by not sure if it is a
>     MUST
>     >> requirement.
>     >>
>     >>
>     >> Cheers
>     >> Suhas
>     >>
>     >> ________________________________________
>     >> From: cowwoc [cowwoc@bbs.darktech.org
>     <mailto:cowwoc@bbs.darktech.org>]
>     >> Sent: Friday, June 14, 2013 6:10 PM
>     >> To: public-webrtc@w3.org <mailto:public-webrtc@w3.org>
>     >> Subject: Re: SDP wrapper? Object-oriented API?
>     >>
>     >>       +1. I understand that the spec authors are determined to
>     stick with
>     >> SDP and that's okay, but can we get the specification to explicitly
>     >> state that SDP arguments are to be treated as read-only opaque
>     tokens at
>     >> this time? This leaves the door open to providing an
>     object-oriented API
>     >> for mutating SDP at some future time.
>     >>
>     >> Gili
>     >>
>     >> On 14/06/2013 3:14 PM, piranna@gmail.com
>     <mailto:piranna@gmail.com> wrote:
>     >>
>     >> Isn't there somewhere a wrapper for SDPs? It's crazy trying to work
>     >> with them, and nothing have been decided yet about using a more
>     >> object-oriented API that modify the SPD strings by hand, while
>     it has
>     >> been agreed several times on this list about SDPs should be
>     >> implementation detail... Also, such wrapper should be a basis
>     where to
>     >> start to develop that higher-level API...
>     >>
>     >> --
>     >> "Si quieres viajar alrededor del mundo y ser invitado a hablar
>     en un
>     >> monton de sitios diferentes, simplemente escribe un sistema
>     operativo
>     >> Unix."
>     >> – Linus Tordvals, creador del sistema operativo Linux
>     >>
>     >>
>     >>
>     >>
>     >>
>     >>
>     >>
>     >> --
>     >>
>     >> Ken Smith
>     >> Cell: 425-443-2359
>     >> Email: smithkl42@gmail.com <mailto:smithkl42@gmail.com>
>     >>
>     >> Blog: http://blog.wouldbetheologian.com/
>     >>
>     >>
>     >>
>     >>
>     >
>
Received on Wednesday, 19 June 2013 13:24:56 UTC

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