Hi Justin,
It would be very desirable to agree on the MTI codecs for both
audio and video to ensure interoperability. As you say people/companies have
different reasons for preferring codecs. In case of video codecs the reality is
that it will be very difficult to reach an agreement over VP8 vs. H.264.
One of the practical reasons to prefer H.264 is that is already
so widely supported. For instance in mobile devices HW acceleration is
important (especially for encoding), and we have it today in many platforms for
H.264, but not necessarily for other video codecs.
Markus
From: ext Justin Uberti
[mailto:juberti@google.com]
Sent: 22 December, 2010 18:15
To: Ingemar Johansson S
Cc: dispatch@ietf.org; rtc-web@alvestrand.no; Isomaki Markus
(Nokia-CIC/Espoo)
Subject: Re: [RTW] [dispatch] Fwd: New Version Notification for draft-alvestrand-dispatch-rtcweb-protocols-00
Ingemar,
RFC 3711 defines AES as the default encryption algorithm and
HMAC-SHA1 as the default authentication algorithm for SRTP. As a result, those
algorithms are used by pretty much every application that uses SRTP, which
makes interoperability much easier.
I think a similar statement can be made regarding the
selection of MTI video codecs. There are various reasons why one might choose
one codec versus another. But if we are unable to pick at least one default/MTI
codec (for each media type), interoperability and thereby adoption of this
platform will be much more challenging.
--justin
On Tue, Dec 21, 2010 at 11:44 PM, Ingemar Johansson S <ingemar.s.johansson@ericsson.com>
wrote:
Hi
Not meaning to express any preference in any direction but more a question to
the more experiened IETFers.
My impression here is that algorithms devised outside the IETF are rarely
mandated in IETF frameworks.
Two examples that I can come up with are
SRTP (RFC3711): Only specifies the framework for secure RTP but does not
mandate any encryption/authentication algorithms. Not sure if excryption algos
are specified in separate RFC's
FECFRAME (RFC6015): Specifies the framework for generic FEC, generic enough to
plug in any FEC algo, the actual FEC algos are specified in separate drafs (http://tools.ietf.org/wg/fecframe/)
Perhaps there are similar examples in other IETF areas that can serve as
guidance ?, you may want to ping the eriIetf list on this (I leave it up to
you)
So to me it seems like there is preference to _not_ mandate algorithms
(compression, fec, encryption) in IETF frameworks (I can imagine one specific
reason to this). And... as I believe that RTC-Web will be some kind of
framework I would say that this would apply here as well ?.
Please feel free to bash my conclusion.
/Ingemar
-------------------------------------------
Message: 1
Date: Tue, 21 Dec 2010 21:38:42 +0000
From: <Markus.Isomaki@nokia.com>
Subject: Re: [dispatch] Fwd: New Version Notification
for
draft-alvestrand-dispatch-rtcweb-protocols-00
Cc: rtc-web@alvestrand.no,
dispatch@ietf.org, ted.ietf@gmail.com
Message-ID:
<DD8B10B86502AB488CB2D3DB4C546E3806DA99@008-AM1MPN1-003.mgdnok.nokia.com>
Content-Type: text/plain; charset="us-ascii"
Hi Peter, all,
About the video codec: Are there any arguments on why VP8 would not have IPR
issues? It is available as an open source implementation, but that does not
mean there are no IPR against it. My understanding is that the IPR situation
wrt. VP8 is still unclear and thus risky. The other issue with VP8 is, as far
as I know, the lack of a clear spec out of which independent interoperable
implementations can be created.
So I don't at least buy the argument that we should choose VP8 as mandatory to
implement video codec because of IPR reasons.
I'm working on a separate review on Harald's drafts (thanks for putting them
together) and will come back to the codec issue there in more detail, but just
wanted to respond to Peter's point here.
Regards,
Markus
From: dispatch-bounces@ietf.org
[mailto:dispatch-bounces@ietf.org]
On Behalf Of ext Peter Musgrave
Sent: 17 December, 2010 13:48
To: Harald Alvestrand
Cc: rtc-web@alvestrand.no; dispatch@ietf.org; Ted Hardie
Subject: Re: [dispatch] Fwd: New Version Notification for
draft-alvestrand-dispatch-rtcweb-protocols-00
I'd also like to echo Alan's thanks for these drafts.
The protocol doc is very clear. [If you read only one dispatch draft this
Christmas, make it this one. ;-) ]
One observation to the group. The mandatory to implement video CODEC is VP8
(presumably since it does not have IPR issues - which some other choices would
have).
Regards,
Peter Musgrave
Nits
Introduction
s/veichle/vehicle/
Section 2 Para "Within each.."
s/implementaiton/implementation/
Section 4 Para1
"such as" (something missing here?)
Section 5 Para2
"There is no third mandatory to implement"
? Was there a mention of a third before. Not sure why this statement is there.
On 2010-11-10, at 6:34 AM, Harald Alvestrand wrote:
This is the overview document for the IETF-related RTC-WEB work.
-------- Original Message --------
Subject:
New Version Notification for draft-alvestrand-dispatch-rtcweb-protocols-00
Date:
Wed, 10 Nov 2010 03:31:05 -0800 (PST)
From:
IETF I-D Submission Tool <idsubmission@ietf.org><mailto:idsubmission@ietf.org>
To:
harald@alvestrand.no<mailto:harald@alvestrand.no>
A new version of I-D, draft-alvestrand-dispatch-rtcweb-protocols-00.txt has
been successfully submitted by Harald Alvestrand and posted to the IETF
repository.
Filename: draft-alvestrand-dispatch-rtcweb-protocols
Revision: 00
Title: Overview: Real Time Protocols for
Brower-based Applications
Creation_date: 2010-11-11
WG ID: Independent Submission
Number_of_pages: 9
Abstract:
This document gives an overview of a protocol suite intended for use
with real-time applications that can be deployed in browsers - "real
time communication on the Web".
It intends to serve as a starting and coordination point to make sure
all the parts that are needed to achieve this goal are findable, and
that the parts that belong in the Internet protocol suite are fully
specified and on the right publication track.
This work is an attempt to synthesize the input of many people, but
makes no claims to fully represent the views of any of them. All
parts of the document should be regarded as open for discussion.
The IETF Secretariat.
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