DEVELOPING THE STANDARDS
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However, the benefits include access to the private documents of MPEG (including access to
the standards in draft form before their official publication, providing a potential market lead
over competitors) and the opportunity to shape the development of the standards.
MPEG conducts its business at meetings that take place every 2–3 months. Since 1988
there have been 64 meetings (the first was in Ottawa, Canada and the latest in Pattaya, Thai-
land). A meeting typically lasts for five days, with ad hoc working groups meeting prior to the
main meeting. At the meeting, proposals and developments are deliberated by each sub-group,
successful contributions are approved and, if appropriate, incorporated into the standardisation
process. The business of each meeting is recorded by a set of input and output documents.
Input documents include reports by ad hoc working groups, proposals for additions or changes
to the developing standards and statements from other bodies and output documents include
meeting reports and draft versions of the standards.
4.2.2 ITU-T VCEG
The Video Coding Experts Group is a working group of the International Telecommunication
Union Telecommunication Standardisation Sector (ITU-T). ITU-T develops standards (or
‘Recommendations’) for telecommunication and is organised in sub-groups. Sub-group 16 is
responsible for multimedia services, systems and terminals, working party 3 of SG16 addresses
media coding and the work item that led to the H.264 standard is described as Question 6. The
official title of VCEG is therefore ITU-T SG16 Q.6. The name VCEG was adopted relatively
recently and previously the working group was known by its ITU designation and/or as the
Low Bitrate Coding (LBC) Experts Group.
VCEG has been responsible for a series of standards related to video communication
over telecommunication networks and computer networks. The H.261 videoconferencing
standard was followed by the more efficient H.263 which in turn was followed by later versions
(informally known as H.263+ and H.263++) that extended the capabilities of H.263. The
latest standardisation effort, previously known as ‘H.26L’, has led to the development and
publication of Recommendation H.264.
Since 2001, this effort has been carried out cooperatively between VCEG and MPEG
and the new standard, entitled ‘Advanced Video Coding’ (AVC), is jointly published as ITU-T
H.264 and ISO/IEC MPEG-4 Part 10.
Membership of VCEG is open to any interested party (subject to approval by the
chairman).VCEG meets at approximately three-monthly intervals and each meeting consid-
ers a series of objectives and proposals, some of which are incorporated into the developing
draft standard. Ad hoc groups are formed in order to investigate and report back on specific
problems and questions and discussion is carried out via email reflector between meetings.
In contrast with MPEG, the input and output documents of VCEG (and now JVT, see below)
are publicly available. Earlier VCEG documents (from 1996 to 1992) are available at [6] and
documents since May 2002 are available by FTP [7].
4.2.3 JVT
The Joint Video Team consists of members of ISO/IEC JTC1/SC29/WG11 (MPEG) and ITU-T
SG16 Q.6 (VCEG). JVT came about as a result of an MPEG requirement for advanced video
coding tools. The core coding mechanism of MPEG-4 Visual (Part 2) is based on rather