Re: [rtcweb] Offer/answer for heterogeneous encode/decode
Derek Pang <dcpang@highfive.com> Tue, 26 November 2013 22:07 UTC
Return-Path: <dcpang@highfive.com>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C543C1ADF84 for <rtcweb@ietfa.amsl.com>; Tue, 26 Nov 2013 14:07:57 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.378
X-Spam-Level:
X-Spam-Status: No, score=-1.378 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FM_FORGED_GMAIL=0.622, HTML_MESSAGE=0.001, J_CHICKENPOX_18=0.6, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Mjqv2nurtkIm for <rtcweb@ietfa.amsl.com>; Tue, 26 Nov 2013 14:07:54 -0800 (PST)
Received: from mail-bk0-f48.google.com (mail-bk0-f48.google.com [209.85.214.48]) by ietfa.amsl.com (Postfix) with ESMTP id 29B5B1ADF7A for <rtcweb@ietf.org>; Tue, 26 Nov 2013 14:07:39 -0800 (PST)
Received: by mail-bk0-f48.google.com with SMTP id v10so2866004bkz.35 for <rtcweb@ietf.org>; Tue, 26 Nov 2013 14:07:39 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type; bh=sj02IsTrR4hVVnYCx9H53dXpuzmmUrJTo8vQCjRaR3k=; b=GqrqZbWdRaoShKvB+CQmiEr23SmYJiizIX/b2E+Zp53EW2xgtoQAkwyJulkHeRmLJx J/+OILqFjNq8+cYOsKouGMAa8ceqIyWHO7k2CYqYJXEyrcXHwMWCy+vtu6/qWXcMtMeZ uermCu0hQAqvi6IbbjFRI6Y8mdlyr9Vf1c7RCr+PnGQml1fCybMc4TmAJI1Tghk4rD4q y8zm5+qalfOoxa4DMgL3vFPqADRDFRTr+WbSKu7ReJD8wnkUlYNW6/G4LyfU8qrJGUzk Iqe3Ow1Npew+afR0d0jV1yz8BD8mdEM+FloBCs6jckwF2n7zcVpyzO+gKgKXsZXzbEdI 1eeg==
X-Gm-Message-State: ALoCoQl+/u6ENyaF5Yb5BrtxPYNVp7GSw0kOBHXwUDL+Jp5OSnm5M+VAskIZd4lTW8gs/a7W0xh+
X-Received: by 10.205.36.81 with SMTP id sz17mr24174720bkb.29.1385503659074; Tue, 26 Nov 2013 14:07:39 -0800 (PST)
MIME-Version: 1.0
Received: by 10.204.162.78 with HTTP; Tue, 26 Nov 2013 14:07:18 -0800 (PST)
In-Reply-To: <52922BA1.6070805@alvestrand.no>
References: <CAOJ7v-2NSo7_KgARkYMDO6bca7msARL83d9gN3570F6sHoCJ9g@mail.gmail.com> <59A91D84-3D29-47C4-8688-CB60844B15D3@cisco.com> <CABkgnnVu8p9nTaWhQYy8GdXkpa6_GGvZwbv8i=kistG5SnskXg@mail.gmail.com> <24B2A6DE-958C-445C-BE77-8BD1661DC33D@cisco.com> <52922BA1.6070805@alvestrand.no>
From: Derek Pang <dcpang@highfive.com>
Date: Tue, 26 Nov 2013 14:07:18 -0800
Message-ID: <CAKE_3BVx9C0MC1sTAo9PNWk+vDWfqF_9fw-nP=8hU8p+Eugz3w@mail.gmail.com>
To: Harald Alvestrand <harald@alvestrand.no>
Content-Type: multipart/alternative; boundary="bcaec52c67756f899504ec1bb5d6"
X-Mailman-Approved-At: Tue, 26 Nov 2013 16:04:03 -0800
Cc: rtcweb@ietf.org
Subject: Re: [rtcweb] Offer/answer for heterogeneous encode/decode
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb/>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 26 Nov 2013 22:10:40 -0000
I am new to rtcweb community. Was there any proposal on making both Vp8 and H264 decoders MTI in webrtc, but VP8 or H264 encoder to be optional ? Does this offer a better option for the marketplace, while allowing interoperability. On Sun, Nov 24, 2013 at 8:38 AM, Harald Alvestrand <harald@alvestrand.no>wrote: > On 11/23/2013 01:20 AM, Paul Giralt (pgiralt) wrote: > >> On Nov 22, 2013, at 7:06 PM, Martin Thomson <martin.thomson@gmail.com> >> wrote: >> >> On 22 November 2013 15:44, Paul Giralt (pgiralt) <pgiralt@cisco.com> >>> wrote: >>> >>>> While you’re right that it would work for this scenario, my point was >>>> really >>>> that Offer/Answer is not really asymmetric as implied earlier. Take for >>>> example the hypothetical case where you are only able to decode VP8 but >>>> only >>>> able to encode H.264. If I offer VP8 as my only codec (because it’s the >>>> only >>>> thing I’m able to decode therefore I never want anyone to send me >>>> anything >>>> other than VP8) I cannot send H.264 in the offer because that implies >>>> I’m >>>> able to decode it. The other side then wants to say it can only receive >>>> H.264 so it would have to send back an answer with only H.264. I guess >>>> there’s nothing really inherently stopping you from doing this because >>>> as >>>> far as I can tell, 3264 only says the answer has to be a subset of the >>>> offer >>>> for multicast streams, however how would the answering side know that >>>> the >>>> offering side is even capable to receiving H.264? Perhaps Offer/Answer >>>> can >>>> technically be asymmetric, but it doesn’t seem practical to use it this >>>> way >>>> because you cannot really indicate your send and receive capabilities >>>> independent of each other. >>>> >>> Judicious application of a=sendonly or a=recvonly avoids this issue. >>> If you want to send H.264, try a=sendonly on a line with H.264. If >>> you want to receive VP8, try a=recvonly on a line with VP8. >>> >> I gave this as an example of a possible way to do it, but that means you >> need two separate m= lines - one for send and one for receive. Seems >> strange to do this for something that you really want to be a single >> bi-directional stream. >> > > An application that can't talk to itself is kind of bizarre too. > > I think this is a corner case. > > > _______________________________________________ > rtcweb mailing list > rtcweb@ietf.org > https://www.ietf.org/mailman/listinfo/rtcweb >
- [rtcweb] Offer/answer for heterogeneous encode/de… Justin Uberti
- Re: [rtcweb] Offer/answer for heterogeneous encod… Paul Giralt (pgiralt)
- Re: [rtcweb] Offer/answer for heterogeneous encod… Martin Thomson
- Re: [rtcweb] Offer/answer for heterogeneous encod… Paul Giralt (pgiralt)
- Re: [rtcweb] Offer/answer for heterogeneous encod… Martin Thomson
- Re: [rtcweb] Offer/answer for heterogeneous encod… Christer Holmberg
- Re: [rtcweb] Offer/answer for heterogeneous encod… Harald Alvestrand
- Re: [rtcweb] Offer/answer for heterogeneous encod… Harald Alvestrand
- Re: [rtcweb] Offer/answer for heterogeneous encod… Derek Pang
- Re: [rtcweb] Offer/answer for heterogeneous encod… Derek Pang
- Re: [rtcweb] Offer/answer for heterogeneous encod… Derek Pang