Subject: [AVT] [dispatch] Proposal to form Internet Wideband Audio Codec WG

From: Roni Even <[email-masked]>
Date: Fri, 29 May 2009 10:35:18 +0300

FYI

All,

I would like to request agenda time inside the DISPATCH meeting to propose
the formation of a new working group to define a Proposed Standard wideband
audio codec.

The text of the proposal is below. Comments, questions, and suggestions
welcomed.

Regards,

Jason

Internet Wideband Audio Codec (IWAC)

Mailing Lists: TBD

Chairs: TBD

Area Directorate: Real Time Applications (RAI)

Purpose:

This new working group would be chartered with the purpose of collecting

expertise within the IETF in order to review the design of audio codecs

specifically for use with the Internet. Unlike other SDOs, these codecs

would be optimized for use on the Internet, and as much as possible choose

technology that does not require paying patent royalties.

The Internet Low Bit Rate Codec (iLBC)  work was done in AVT but it was felt

that subsequent work should not be done in the AVT working group. This new

working group will have as its primary purpose the standardization of a

multi-purpose audio codec that can be used in various situations on the

Internet. Some of the proposed Internet-specific requirements include:

* scalable and adaptive bit rate;

* various sampling rate profiles from narrow-band to super-wideband;

* scalable complexity;

* low latency; and 

* resilience to packet loss.

There are a number of wide-band capable codecs defined by other SDOs. For

instance, G.722 is seeing adoption in Enterprise applications since it is

relatively simple and low-cost to deploy. However, it has a high, fixed

bitrate and is not appropriate for mobile applications where spectrum

efficiency is important or in consumer applications where available

bandwidth is fluctuating or limited. G.722.2 (AMR-wideband) has been adopted

by the 3GPP as a wideband standard for mobile applications. G.722.2 is

relatively high cost due to patent royalties and is seeing minimal

deployments outside of mobile handsets making it challenging to create

wideband experiences on Internet-capable mobile devices when extending

beyond the mobile network. In other cases, proprietary codecs are being

adopted which further create islands with no interoperability unless

widespread transcoding is performed. Transcoding leads to higher costs and

lower quality. 

The goal of this working group is to define a single codec with multiple

profiles which can be made available on a wide variety of Internet-capable

devices including low-power, mobile devices as well as devices capable of

utilizing high quality, high bitrate audio.

Proposed Deliverables:

1) Requirements for wideband, Internet audio codec(s).

2) Algorithm description for wideband, Internet audio codec(s) as Proposed

Standard. 

3) Specification of payload format(s) for defined codecs as Proposed

Standard

_______________________________________________

dispatch mailing list

[email-masked]

https://www.ietf.org/mailman/listinfo/dispatch

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From: John Lazzaro <[email-masked]>
Date: Fri, 29 May 2009 09:31:26 -0700

Hi everyone,

Brief comment below ...

> specifically for use with the Internet.

A traditional response to this type of request is to note that the IETF
really doesn't have much in the way of expertise in audio codec design.
I don't see many of the regulars who present at the AES codec paper sessions
posting here on AVT (ditto ICASSP paper sessions for voice codecs). It's
a full-time job to keep up-to-date and contribute to that
signal-processing lore.

-- 
John Lazzaro
http://www.cs.berkeley.edu/~lazzaro
john [dot] lazzaro [at] gmail [dot] com

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From: stephen botzko <[email-masked]>
Date: Fri, 29 May 2009 13:00:32 -0400

In addition, rigorously testing the codec's quality is a specialized
discipline in its own right.  In other standards bodies the testing is
frequently done by an independent working group (that just does testing).

Stephen Botzko

On Fri, May 29, 2009 at 12:31 PM, John Lazzaro <[email-masked]>wrote:

> http://www.cs.berkeley.edu/~lazzaro<http://www.cs.berkeley.edu/%7Elazzaro>
> Audio/Video Transport Working Group
> [email-masked]
> https://www.ietf.org/mailman/listinfo/avt
>

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From: Jean-Marc Valin <[email-masked]>
Date: Fri, 29 May 2009 16:18:09 -0400

> a full-time job to keep up-to-date and contribute to that

Well, there's no reason that the IETF cannot build such an expertise in 
audio codecs. This is actually something in which I'd be interested in 
getting involved and I'm sure others at Xiph.Org would be interested as 
well. We have several people with audio codec expertise from working on 
Vorbis, Speex and (more recently) CELT. It turns out that the CELT codec 
currently under development at Xiph actually meets most of the 
requirements from the original proposal in being a very low delay codec 
with adaptive bit-rate and sampling rate (up to 48 kHz), scalable 
complexity, and good robustness to packet loss. We'd be willing to 
continue the development with the IETF. Even if not with CELT, it's 
still like to be involved in such a new WG.

Cheers,

    Jean-Marc