MPEG-2 effort reaches International Standard (Press Release)

[David Farber <farber () central cis upenn edu>]

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


                                        ISO/IEC JTC1/SC29/WG11 N0822
                                                            MPEG 94/
                                                    11 November 1994




Source: Leonardo Chiariglione - Convenor
Title:  Press release
Status: Approved at 29th meeting




                                Press Release


Summary:
The 29th meeting of ISO/IEC JTC1/SC29/WG11 (MPEG) was held in Singapore
this week, hosted by the National Computer Board and the National IT
Standards Committee (Singapore).  The results achieved at this meeting
include: the final approval of part 4 of ISO/IEC 11172-4 (MPEG-1
Conformance Testing) as International Standard (IS); the promotion of
ISO/IEC 11172-5 (Software for MPEG-1 coding) to Draft International
Standard (DIS) status; the final approval of ISO/IEC 13818-1 (MPEG-2
Systems), ISO/IEC 13818-2 (MPEG-2 Video) and ISO/IEC 13818-3 (MPEG-2
Audio) as IS; the production of the Working Draft of the DSM-CC
(Digital Storage Media Command and Control) extension; and the issuing
of a Call for Proposals for MPEG-4, the next item of work.


The approval of MPEG-2 for publication as an international standard
constitutes an important milestone in international standardization
that will make possible the establishment of interoperable digital
audio-visual services and applications on a world-wide scale while
making sure that international standardisation of digital audio-visual
matters will not be overtaken by the progression of technology.  The
continuing work will ensure continued responsiveness to the needs of
the digital audio-visual community.




Systems:
This week saw the promotion of the Draft International Standard
13818-1, better known as "MPEG-2 Systems" to IS status. This part of
the MPEG-2 standard provides for the multiplex and synchronisation of
multiple audio, video, and data streams. MPEG-2 Systems will form the
infrastructure for delivery of audio and video information in many
industry sectors, including television distribution, visual
telecommunications, and a host of computer and multimedia
applications.


MPEG-2 Systems specifies two syntaxes, the Transport Stream and the
Program Stream, each designed for different applications. Both syntaxes
offer a wide range of functions and capabilities. In addition to
multiplexing, a major feature is the accurate synchronisation of audio,
video, and data for correct presentation at the decoder. The standard
addresses the management of buffers at the decoder. Additional
functions include random access, identification of information carried
within the stream, procedures to support user access control, and error
protection mechanisms.


Contribution to the development of the MPEG-2 Systems standard has come
from many different industry groups, representing the wide range of
interest in the standard. ITU-T Study Group 15 has also participated in
the development of the standard and the ITU-T will adopt MPEG-2 Systems
as ITU-T Recommendation H.222.1, as part of its Broadband-ISDN audio
visual telecommunications terminal.


With new transmission technologies allowing high bandwidth connections,
and switching technologies such as ATM, MPEG-2 Systems will form the
basis of new audio and visual services applications for many years to
come.




Digital Storage Command and Control:
The Working Draft of the Digital Storage Media Command and Control
(DSM-CC) extension was also completed this week. This standard will
facilitate the interoperability of MPEG applications and equipment by
providing a common command and control interface. An example
application is the control of remote video servers from home based
terminals. A Committee Draft (CD) of the DSM-CC Extension is scheduled
for March 1995 and International Standard in November 1995.


A requirements document on a multimedia scripting language was also
produced. The standard will be developed together with the Multimedia
and Hypermedia Experts Group (MHEG), a parallel committee within
JTC1/SC29. The language is an important element for the rapid
introduction of stand-alone and networked interactive multimedia
applications and services.




Real Time Interface:
Part 9 of ISO/IEC 13818 is the Real Time Interface (RTI), an extension
of the MPEG-2 Systems standard defining a common interface point to
which terminal equipment manufacturers and network operators can
design. RTI specifies a delivery model for the bytes of an MPEG-2
Systems stream at the input of a real decoder, while MPEG-2 Systems
defines an idealised byte delivery schedule. Part 9 was promoted to
Working Draft (WD) status at this week's Singapore meeting. It is
expected to become an International Standard in November 1995.






Video:
The standard 13818-2, better known as 'MPEG-2 Video' was promoted from
DIS to IS status. The standard provides for the digital coding of video
at various data rates from about 1.5 Mbit/s to in excess of 60 Mbit/s,
enabling a common technology to be adopted for many applications
ranging from home entertainment quality video up to HDTV. Subsets of
the total video standard known as profiles have been defined to assist
in interchange of coded video data between these various applications.
Early adopters of this standard include pay-TV cable and satellite
broadcasters as well as the emerging interactive 'Video on Demand'
market, for which the 'Main Profile' is identified as the most
suitable. Other profiles support layered coding techniques suitable for
terrestrial broadcasting and IT environments.


MPEG-2 Video has been developed jointly with ITU-T SG 15 and will be
adopted by that Standards Body as Recommendation H.262.


10 bit video and new profiles:
The need to extend the MPEG-2 tools and provide support of efficient
bitrate reduction for high-quality video signals quantised with 10
bits, such as those used in the studio, has been recognised and a Call
for Proposals has been issued in July 1994. The deadline for
submissions is March 1995, but a number of companies have already
stated their intention to make proposals.  At this meeting another
range of applications which may take benefit from the MPEG technology
has been identified regarding compression coding of
non-chroma-subsampled ordinary video signals at bitrates up to 50
Mbit/s. While many of the committee members are confident that the MPEG
coding tools can be successfully applied at these high bitrates, the
very demanding performance required by the mentioned applications has
prompted MPEG to establish an ad-hoc group with the mandate of
providing technical evidence to be submitted at the 30th MPEG meeting
in March 1995. The successful outcome of the work of the ad-hoc group
will enable MPEG to make a decision on this important extension of its
current work.




Video Quality Verification Test:
MPEG has put considerable efforts into evaluating the quality obtained
by the application of its standards to video information sources. This
evaluation has been made on various MPEG-2 video profiles for TV and
HDTV.


A first set of results, obtained as early as March through a set of
test video sequences, proved that MPEG-2 Video at 9 Mbit/s coding
provides near transparent quality while at 6 Mbit/s the quality equals
or exceeds that of conventional TV systems. At lower bit rates, such as
4 Mbit/s high quality pictures will be obtained on most picture
material.


Expert viewing tests were also carried out on the "Spatially Scalable
Profile at H14", a profile for 1440 line HDTV. This profile defines
layered coding techniques used to generate a base layer bitstream with
an enhancement layer bitstream used to create a higher resolution
image. The layered coding allows simultaneous reception of an HDTV
signal by both HDTV and standard resolution TV receivers.


Initial results seem to indicate that the high layer satisfies the
required quality for HDTV at 36 Mbit/s. The quality of the base layer,
using 9 of the 36 Mbit/s, is high enough for normal TV broadcasting; it
is however not sufficient for an HDTV 'fall back solution', which could
occur in the case of bad reception conditions.


More tests are planned for testing MPEG-2's "Main Profile" for HDTV use
at bitrates of 18, 30 and 45 Mbit/s. Taking into account the intended
use of these profiles, the tests will be carried out with video and
movie material.




Audio:
The multichannel MPEG-2 Audio coding system (IS13818-3) has been
promoted to IS status during the Singapore meeting. This standard
supports the extension of the MPEG-1 Audio compression standard
(ISO/IEC 11172-3) to multichannel (up to 5 channels). It also supports
the extensions of the MPEG-1 Audio compression standard to lower
sampling frequencies and lower bitrates. These extensions have proven
to outperform conventional speech codecs at the same rates.


Use of the MPEG-2 Audio standard will be further promoted through
continuing work on improvements in quality, largely dependent on
encoder optimisation, and the distribution of reference software and
compressed multichannel audio sequences over the Internet.


MPEG is also working on the development of a multichannel audio coding
standard that is not backward compatible to MPEG-1 Audio but still part
of the MPEG-2 standard. A Call for Proposals was issued in July 1994
and twelve companies have already responded presenting an outline of
their intended proposals. Detailed proposals will be presented at the
next MPEG meeting (March '95), but the collaboration among the
proposers has already started in Singapore using a common reference
model.




MPEG-4:
In its MPEG-4 phase of work MPEG will develop an audio-visual coding
standard with new functionalities, such as support for manipulation of
the content of audio-visual data, that will find application in diverse
areas such as entertainment, distance learning, remote monitoring, and
home shopping. Thus continuous improvement in performance of coding is
necessary. To provide this capability, MPEG-4 will develop a flexible
syntactic descriptive language, and a number of audio-visual coding
tools. This approach will provide the ability for decoders to use a
rich set of algorithms according to the content or applications.




Software implementations of MPEG standards:
The full software implementation of the three parts of MPEG-1,
contained in part 5 of MPEG-1, was promoted to Draft Technical Report
status at this meeting. The software is an aid to implementors and
novices providing an example encoder and decoder for Systems, Video,
and Audio. This software has also a wide domain of applicability thanks
to the ever increasing processing capability of computers that promise
to make possible software implementation of the standard under certain
conditions.


The same work is also being carried out for MPEG-2: a technical report
for MPEG-2 Video, including reference software for coding and decoding,
was approved for balloting as Proposed Draft Technical Report 13818-5.




Conformance testing:
The work on MPEG-1 conformance testing was closed at this meeting. This
part of MPEG-1 guarantees the quality of MPEG-1 products, and helps to
make sure that they conform to the standard.


The work on MPEG-2 Conformance is at an advanced stage of development:
the conformance document was reviewed and approved as CD 13818-4 and
submitted for balloting.




Technical note:
MPEG is the nickname of an ISO working group. As such it is assigned
work items and produces standards. Therefore there is no such thing as
an "MPEG-2 committee".  This is the full list of work items




11172 (MPEG-1)  Coding of moving pictures and associate audio for digital
                storage media at up to about 1.5 Mbit/s


                                                   IS date (Year/Month)


Part 1   Systems                                   92/11
Part 2   Video                                     92/11
Part 3   Audio                                     92/11
Part 4   Conformance testing                       94/11
Part 5   Simulation software                       95/03




13818 (MPEG-2) Generic coding of moving pictures and associated audio


Part 1   Systems                                   94/11
Part 2   Video                                     94/11
Part 3   Audio                                     94/11
Part 4   Conformance testing                       95/07
Part 5   Simulation software                       95/07
Part 6   Digital storage media command and control 95/09
Part 7   Non-backwards compatible audio            97/03
Part 8   10 bit video                              96/07
Part 9   Real-time interface                       95/11




14496 (MPEG-4) Very low bitrate audio-visual coding


Part 1   Systems                                   98/11
Part 2   Video                                     98/11
Part 3   Audio                                     98/11
----
End of MPEG November 11, 1994 Press Release document WG11 N0822