MPEG-FAQ 4.1:

What happened at the MPEG - NY meeting ?

From: cfogg@ole.cdac.com (Chad Fogg)

Date: 22 Jul 93 05:31:41 GMT

INTERNATIONAL ORGANISATION FOR STANDARDISATION
ORGANISATION INTERNATIONALE DE NORMALISATION
ISO/IEC JTC1/SC29/WG11
CODING OF MOVING PICTURES AND ASSOCIATED AUDIO

ISO/IEC JTC1/SC29/WG11  N0500
July 16, 1993

Source:	ISO/IEC JTC1/SC29/WG11
~Title:	Press Release (Final) -- MPEG New York Meeting
Status:	For immediate release


Summary

This week in New York, at a meeting hosted by Columbia University, the 
Moving Picture Experts Group (MPEG) completed definition of MPEG-2 
Video, MPEG-2 Audio, and MPEG-2 Systems.  MPEG therefore confirmed 
that it is on schedule to produce, by November 1993, Committee Drafts of 
all three parts of the MPEG-2 Standard, for balloting by its member 
countries.

To ensure that a harmonized solution to the widest range of applications 
is achieved, MPEG, an ISO/IEC working group designated ISO/IEC 
JTC1/SC29/WG11, is working jointly with the ITU-TS Study Group 15 
"Experts Group for ATM Video Coding." MPEG also collaborates with 
representatives from other parts of ITU-TS, and from EBU, ITU-RS, SMPTE, 
and the North American HDTV community.


MPEG-2 Video

MPEG is developing the MPEG-2 Video Standard, which specifies the coded 
bit stream for high-quality digital video.  As a compatible extension, 
MPEG-2 Video builds on the completed MPEG-1 Video Standard (ISO/IEC IS 
11172-2), by supporting interlaced video formats and a number of other 
advanced features, including features to support HDTV.  

As a generic International Standard, MPEG-2 Video is being defined in 
terms of extensible profiles, each of which will support the features 
needed by an important class of applications. At the March MPEG meeting 
in Sydney, the MPEG-2 Main Profile was defined to support digital video 
transmission in the range of about 2 to 15 Mbits/sec over cable, satellite, 
and other broadcast channels, as well as for Digital Storage Media (DSM) 
and other communications applications. Building on this success at this 
week's New York meeting, MPEG experts from participating countries in 
Asia, Australia, Europe, and North America further defined parameters of 
the Main Profile and Simple Profile suitable for supporting HDTV formats.

This week the MPEG experts also extended the features of the Main Profile 
by defining a hierarchical/scalable profile.  This profile aims to support 
applications such as compatible terrestrial TV/HDTV, packet-network 
video systems, backward-compatibility with existing standards (MPEG-1 
and H.261), and other applications for which multi-level coding is 
required.  For example, such a system could give the consumer the option 
of using either a small portable receiver to decode standard definition TV, 
or a larger fixed receiver to decode HDTV from the same broadcast signal.

This week's accomplishments in New York mean that the technical 
definition of MPEG-2 Video has been completed.  This was a critical 
milestone, and shows that MPEG-2 Video is on schedule for a Committee 
Draft in November.


MPEG-2 Audio

MPEG is developing the MPEG-2 Audio Standard for low bitrate coding of 
multichannel audio. MPEG-2 Audio coding will supply up to five full 
bandwidth channels (left, right, center, and two surround channels), plus 
an additional low frequency enhancement channel, and/or up to seven 
commentary/multilingual channels. The MPEG-2 Audio Standard will also 
extend the stereo and mono coding of the MPEG-1 Audio Standard (ISO/IEC 
IS 11172-3) to half sampling-rates (16 kHz, 22.05 kHz, and 24 kHz), for 
improved quality for bitrates at or below 64 kbits/s, per channel.

This week in New York, MPEG produced an updated version of the MPEG-2 
Audio Working Draft, and is on track for achieving a Committee Draft 
specification by the November MPEG meeting.

The MPEG-2 Audio multichannel coding Standard will provide 
backward-compatibility with the existing MPEG-1 Audio Standard 
(ISO/IEC IS 11172-3). Together with ITU-RS, MPEG is organizing formal 
subjective testing of the proposed MPEG-2 multichannel audio codecs and 
up to three non-backward-compatible (NBC) codecs. The NBC codecs are 
included in order to determine whether an NBC mode should be introduced 
as an addendum to the standard. If the results show clear evidence that an 
NBC mode improves the performance, a formal call for NBC proposals will 
be issued by MPEG, with a view to incorporate these features in the audio 
syntax.


MPEG-2 Systems



MPEG is developing the MPEG-2 Systems Standard to specify coding 
formats for multiplexing audio, video, and other data into a form suitable 
for transmission or storage. There are two data stream formats defined: 
the Transport Stream, which can carry multiple programs simultaneously, 
and which is optimized for use in applications where data loss may be 
likely, and the Program stream, which is optimized for multimedia 
applications, for performing systems processing in software, and for 
MPEG-1 compatibility.

Both streams are designed to support a large number of known and 
anticipated applications, and they retain a significant amount of 
flexibility such as may be required for such applications, while providing 
interoperability between different device implementations.  The 
Transport Stream is well suited for transmission of digital television and 
video telephony over fiber, satellite, cable, ISDN, ATM, and other 
networks, and also for storage on digital video tape and other devices.  It 
is expected to find widespread use for such applications in the very near 
future.

The Program Stream is similar to the MPEG-1 Systems standard (ISO/IEC 
11172-1).  It includes extensions to support new and future applications.  
Both the Transport Stream and Program Stream are built on a common 
Packetized Elementary Stream packet structure, facilitating common 
video and audio decoder implementations and stream type conversions.  
This is well-suited for use over a wide variety of networks with 
ATM/AAL and alternative transports. This week in New York, MPEG 
completed definitions of the features, syntax, and semantics of the 
Transport and Program Streams, enabling product designers to proceed.  
Among other items, the Transport Stream packet length was fixed at 188 
bytes, including the 4-byte header.  This length is suited for use with ATM 
networks, as well as a wide variety of other transmission and storage 
systems.