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Motivation:

There is interest and value in having widely, easily distributable and
accessible codec technology from the Internet community. Codec experts
from both within and outside the IETF community have expressed an
interest in contributing effort in this area. The IETF standards process
provides a model for producing standards that encourages transparent
design and open collaboration early on in the process. Any IETF codec
designs that may emerge will also benefit from input and review from
other RAI working groups and other areas of the IETF.

Goals:

The goal of this working group is to standardize audio codecs that can
be implemented, distributed, and used broadly, and be interoperable
between a wide set of interested parties. The group is chartered to work
on audio codecs for interactive communication over the Internet. Codecs
optimized for very low bit rates or for non-interactive audio are out of
scope. The codecs should address the following technical considerations:

 * suitability for most fixed-point Digital Signal Processors (DSP);
 * medium- to high-quality speech at moderate bit-rate;
 * high-quality music encoding at higher bit-rates;
 * sampling rate profiles from narrow-band to full audio bandwidth;
 * real-time adaptive bit rate;
 * source-controlled variable bit-rate (VBR);
 * low algorithmic delay;

Beyond technical considerations, IPR issues will be handled in
accordance with BCP 78 and BCP 79. Specifically, many existing codecs
with the technical attributes listed above are encumbered with licensing
fees and other IPR claims that make royalty-free and wide distribution
and use across the Internet community difficult. The working group will
try to standardize codecs that can be relatively freely and easily
distributed, and employed as much as possible. In doing so, it will
adhere closely to these BCPs. More specifically, "In general, IETF
working groups prefer technologies with no known IPR claims or, for
technologies with claims against them, an offer of royalty-free
licensing." Note that in accordance with BCP 79, this working group will
not explicitly rule out the possibility of adopting technology that does
not meet these IPR requirements; the decision will be left to the normal
rough consensus of the working group.

Deliverables:

1) Codec Standardization Guidelines - that define a set of metrics which
can be used to evaluate a codec. These metrics would include complexity,
quality vs bitrate, algorithmic delay, packet loss performance and
footprint. The complete list will be specified in this document. An
evaluation of these metrics should be considered by the working group in
trying to come to consensus about proposed changes to one of the draft
codecs. A set of pass/fail requirements MAY be specified in the
requirements document. It will be up to the working group to evaluate
whether or not the proposed codec is better than the reference codec.
Continuous testing will be done throughout the process. After a codec is
finalized, these guidelines will be used to characterize the codec. This
is an Informational track document.

2) Requirements Document - that defines the application requirements of
the resulting solution. The requirements will include the exact
technical considerations including the target values for metrics defined
in the Codec Standardization Guidelines, any pass/fail requirements, an
optional reference codec, the scenarios that are being addressed and the
assumptions about the Internet operating environment. This is an
Informational track document.

3) Algorithm description for one or more wideband Internet audio codecs.
There MUST be a text description of the algorithm as well as a reference
implementation. The reference implementation MUST include an encoder and
a decoder, and MUST be compliant with BCP 78 and BCP 79. The text
description MUST indicate those components of the encoder and decoder
which are mandatory, recommended and optional. For example, in some
codec definitions only the decoder is specified whereas others have
bit-exact specifications. Any characterization MUST be performed with
the reference encoder. This is a Proposed Standard document.

It is not necessary to produce a single codec that solves the entire
range of scenarios. A codec may be approved by the working group without
addressing all of the scenarios.

Milestones:

Jan-2010: WGLC on Codec Standardization Guidelines
Jan-2010: WGLC on Requirements
Jul-2010: WGLC on codec algorithm description(s) to IESG
Mar-2010: Codec Standardization Guidelines to IESG (Informational)
Mar-2010: Requirements to IESG (Infomational)
Jan-2011: Submit codec algorithm description(s) to IESG (Standards Track)