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1. Introduction
MPEG
is a working group of ISO, the International
Organisation for Standardisation. Its formal name is ISO/IEC JTC 1/SC 29/WG
11. The title is: Coding of moving pictures and audio.
The are of work assigned to it is: Development
of international standards for compression, decompression, processing, and coded
representation of moving pictures, audio, and their combination, in order to
satisfy a wide variety of applications.
The full MPEG terms of reference can be found here.
MPEG
held its first meeting in Ottawa, ON (CA) on 88/05/10-12. Until
January 2006 when it met in Bangkok (TH), MPEG has met as a group 75 times. The full list of meeting dates
and venues can be found here.
2. MPEG-1 (ISO/IEC 11172)
The first MPEG work
item was: Coding of moving pictures and associated audio for digital storage
media at up to about 1.5 Mbit/s. In practice this meant a standard for efficient
storage and retrieval of audio and video on compact disc. Parts 1 (Systems),
part 2 (Video) and part 3 (Audio) of the standard were approved at the November
1992 meeting in London. The Systems part provide multiplexing and synchronisation
support to elementary Audio and Video streams. The Video part provides efficient
encoding of non-interlaced pictures with roughly VHS quality at 1,15 Mbit/s.
The Audio part provides encoding of stereo audio with transparency (i.e. subjective
quality similar to the original streo) at 384, 256 and 192 kbit/s per
Layer II, II and III respectively. A more comprehensive description of
the standard can be found here.
Part 4 of the standard "Conformance Testing"
provides methods and reference bitstreams that can be used to assess conformance
of a bitstream or of a decoder, was approved one year later. Part 5 of the standard
"Reference Software" was approved in 1994. The latter contains the
C-code implementation of a Systems multiplexer/demultiplexer and of encoders
and decoders for Audio and Video.
This is the table of MPEG-1 parts:
|
11172 |
(MPEG-1) |
Coding of moving pictures
and associated audio at up to about 1.5 Mbit/s |
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Part 1 |
Systems |
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Part 2 |
Video |
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Part 3 |
Audio |
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Part 4 |
Conformance testing
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Part 5 |
Software simulation
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MPEG-1 has been and is being used by many
industries in a variety of products, services and applications and has triggered
the start of a number of others.
There are many versions of a full MPEG-1 audiovisual
players that can be used in a software environment. These utilise all 3 parts
of Audio standard with Audio typically in Layer II. Many software packages exists
that are capable of encoding audio and video in MPEG-1 and editing the resulting
files.
The Video CD is a full application of MPEG-1
that is typically used to encode movies on 2 CDs. Several hundreds million hardware
Video CD decoders have been sold worldwide and billions of Video CD discs have
been printed. Software Video CD decoders are also avilable from multiple sources.
MPEG-1 Audio Layer III, also known as MP3,
has been implemented in manifold ways. Many software packages exist to rip a
track from a CD Audio and compress it in MP3. This has given rise to innovative
ways of consuming music, such as the ability to create compilations to one's
liking that can then downloaded to light non-mechanical MP3 players. With the
arrival of MP3 the music world has been changed without recognition.
2. MPEG-2 (ISO/IEC
13818)
The Porto meeting in July 1990 was the first
to address the MPEG-2 standard called "Generic coding of Moving Pictures
and Associated Audio" and the Singapore meeting in November 1994 was the
one that approved the first 3 parts: Systems, Video and Audio. Conformance (part
5) was approved one year later and Reference Software in 1996. The Systems part,
in its "Transport Stream" version, provides support for efficient
transmission over error-prone delivery systems, while the "Program Stream"
version, similar to MPEG-1 Systems, is more useful for digital storage media.
The Video part provides support for efficient coding of interlaced pictures
ad different spatial resolution. The Audio part provides support to encoding
of multi-channel audio in such a way that an MPEG-1. A more comprehensive
description of the standard can be found here.
MPEG-2 has more parts than MPEG-1. Part 6
"Digital Storage Media Command and Control' or DSM-CC provide protocols
for session set up across different networks and for remote control of a server
containing MPEG-2 content. Part 7 "Advanced Audio Coding" or AAC provides
a new multichannel audio coding that is not backward compatible with MPEG-1
Audio. Part 8 was intended to support video coding when samples are represented
with an accuracy of more than 8 bits, but its development was discontinued when
the interest of the industry that had requested it did not materialise. Part
9 "Real Time Interface" provides a standard interface between an MPEG-2
Transport Stream and a decoder.
|
13818 |
(MPEG-2) |
Generic coding of moving
pictures and associated audio |
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Part 1 |
Systems |
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Part 2 |
Video |
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Part 3 |
Audio |
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Part 4 |
Conformance testing
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Part 5 |
Software simulation
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Part 6 |
System extensions - DSM-CC
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Part 7 |
Advanced Audio Coding
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Part 8 |
VOID - (withdrawn)
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Part 9 |
System extension RTI
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Part 10 |
Conformance extension -
DSM-CC |
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Part 11 |
IPMP on MPEG-2 Systems
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Parts 1, 2 and 3 (this last one sometimes
replaced with a proprietary solution) are used in the some 50 million digital
television set top boxes and 10 million Digital Versatile Discs (DVD). Some
MPEG-2 encoders are very costly professional equipment and some are very inexpensive
PC board that are sold with video editing software.
Several examples of DSM-CC is widely used
in set top boxes for satellite and cable. This part of the standard is also
at the basis of provision of other set top box functionalities by other standards
bodies and industry consortia. AAC has been adopted by Japan for a national
digital television standard and by several manufacturers of secure digital music.
Over the years several amendments, i.e. extensions, of the
standard have been developed. One of the most important is the 4:2:2 profile
that extends the use of MPEG-2 into the television studio.
A number of patents are thought to be relevant for implementing
the MPEG-2 standard. As MPEG is prevented by ISO rules to deal with patent issues,
there is at least one organisation known that handles the licensing of MPEG-2
Systems and Video and another of MPEG-2 Audio.
3. MPEG-4 (ISO/IEC
14496)
Work on the MPEG-4 standard "Coding of audio-visual
objects" began in July 1993 in New York, NY and the first set of standards
(so-called version 1) was approved at the Atlantic City, NJ meeting in October
1998. A major extension of the standard (so-called version 2) was approved at
the Maui, HI meeting in December 1999.
The first 6 parts of the standard correspond roughly to those
of MPEG-2. The title of the first 5 is the same as MPEG-2, the title of the
6th is Delivery Multimedia Integration Framework. There are, however, a number
of significant differences of content.
MPEG-4 enables the coding of individual objects. This means
that the video information needs not be of rectangular shape as MPEG-1 and MPEG-2
Video assume. The same applies for audio, which provides all tools to encode
speech and audio ad different rates and with different functionalities, including
an extension of AAC. The systems part, therefore, contains, in addition to the
traditional parts of MPEG-1 and MPEG-2 Systems, also the "composition function.
Further, since a composition object can be also of synthetic nature, MPEG-4
Systems also contains standard technology to represent time-varying synthetic
3D information. A framework to deal with management and protection of rights
arising from individual objects is also provided by MPEG-4 Systems. Finally
a file format has been standardised. Part 5 is a complete software implementation
of both encoders and decoders. Compared with the reference software of MPEG-1
and MPEG-2 whose value is purely informative, the MPEG-4 Reference Software
has the same normative value as the textual parts of the standard. The software
may also be used for commercial products and the copyright of the software is
licensed at no cost by ISO/IEC for products conforming to the standard. Part
6 has similar functions as DSM-CC and provides an abstraction from the underlying
delivery mechanism. A more comprehensive description of the standard can be
found here.
So far the industry has enthusiastically
taken over MPEG-4 Video. MPEG-4 Video has been selected by several industry
fora setting standards for next generation mobile communication and is being utilised to develop solutions for video on demand and related applications.
An important MPEG-2 amendment has been developed to support
the carriage of MPEG-4 objects on MPEG-2 Transport Streams. This will enable
rich multimedia applications in the television domain.
Parts 1, 2, 3 and 6 of the version 1 and 2 portions of the
standard have been integrated in what is now called the 2000 edition. Part 5
has been integrated as 2001 edition. Relative to that a number of extensions
are being worked on.
The full list of MPEG-4 parts is
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14496 |
(MPEG-4) |
Coding of audio-visual
objects |
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Part 1 |
Systems |
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Part 2 |
Visual |
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Part 3 |
Audio |
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Part 4 |
Conformance testing
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Part 5 |
Reference Software
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Part 6 |
Delivery Multimedia
Integration Framework |
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Part 7 |
Optimised software for
MPEG-4 tools |
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Part 8 |
4 on IP framework
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Part 9 |
Reference Hardware
Description |
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Part 10 |
Advanced Video Coding
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Part 11 |
Scene Description and
Application Engine |
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Part 12 |
ISO Base
Media File Format |
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Part 13 |
IPMP Extensions |
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Part 14 |
MP4 File Format |
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Part 15 |
AVC File Format |
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Part 16 |
Animation Framework
eXtension (AFX) |
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Part 17 |
Streaming Text Format
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Part 18 |
Font compression and
streaming |
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Part 19 |
Synthesized Texture Stream
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Part 20 |
Lightweight Application
Scene Representation |
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Part 21 |
MPEG-J Extension for
rendering |
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Part 22 |
Open Font Format
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A brief explanation of some of the main items follows:
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XMT is a textual format that encompasses (parts of) other
XML format such as SMIL and Web3D and that can be compiled to the binary
MPEG-4 format (BIFS)
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Animation framework supports rich 3D environment
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IPMP (Intellectual Property Management and Protection)
provides an extension to the IPMP-H Framework that provides interoperability at the user level.
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Studio Profile extends the Video algorithm to bitrates
in the range of 1 Gbit/s for studio applications
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FGS (Fime Granularity Scalability) extends the Video
algorithm to support scalability with a high number of levels
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AVC is the new generation of video coding algorithm
MPEG-4 is a standard that can be used in manifold application
areas, each with their own agendas and practices concerning the business models
of how technology is actually deployed. As again a number of patents are thought
to be relevant for implementing the MPEG-4 standard and as MPEG is prevented
by ISO rules to deal with patent issues, the MPEG-4
Industry Forum has been established as a not-for-profit organisation external
to MPEG with the goal of promoting the adoption of the standard and in particular
creating the conditions for patent tpool administrators to set up patent pools.
4. MPEG-7 (ISO/IEC 15938)
Work on MPEG-7 "Multimedia Content Description Interface"
standard started at the April 1997 meeting in Bristol. MPEG-7 is an audio-visual
information representation that is different from the previous MPEG standards
in the sense that what is represented is not the information itself but the
information about the information. MPEG-7 is an 11-part standard:
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15938 |
(MPEG-7) |
Multimedia Content
Description Interface |
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Part 1 |
Systems |
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Part 2 |
Description Definition
Language |
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Part 3 |
Visual |
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Part 4 |
Audio |
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Part 5 |
Multimedia Description
Schemes |
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Part 6 |
Reference Software
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Part 7 |
Conformance |
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Part 8 |
Extraction and Use of MPEG-7
Descriptions |
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Part 9 |
Profiles |
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Part 10 |
Schema definition
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Part 11 |
Profile schemas |
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Part 12 |
Query Format |
The technical content of the standard is as follows:
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Systems provides the architectural framework of the standard,
the carriage of MPEG-7 content and the binarisation of MPEG-7 content
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Description Definition Language allows
to create descriptors and description schemes
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Visual provides standard descriptors
and description schemes that are purely visual
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Audio provides standard descriptors
and description schemes that are purely audio
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Multimedia Description Schemes provides
standard descriptors and description schemes that are neither visual nor
audio
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Reference software has the same normative
value as the MPEG-4 reference software and may be used for products at the
same conditions
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Conformance is the means to test an
implementation or data for conformity.
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Part 8 describes how feature extraction
can be implemented
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Part 9 provides a set of profiles
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Part 10 the MPEG-7 schema definition
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Part 11 collects the profile
schemas
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Part 12
specifies the interface between a requester for and a responder of
multimedia content retrieval systems
5. MPEG-21 (ISO/IEC 21000)
Work on MPEG-21 "Multimedia Framework" standard
started at the May-June 2000 meeting in Geneva. MPEG-21 provides a multimedia framework and sets
out a vision for the future of an environment where delivery and use of all
content types by different categories of users in multiple application domains
will be possible.
MPEG-21 assumes that there are Users (anybody in
the value network) and Digital Items (assembly of content) on which
Users execute Actions that generate other Digital Items that can become
object of Transactions. In order to make this possible a number of technologies
are needed that fall under the following categories
- Digital Item Declaration
- Digital Item Identification
- Intellectual Property Management and Protection
- Terminals and Networks
- Digital Item Management and Usage
- Digital Item Representation
- Event Reporting
The
current table of MPEG-21 standards is
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21000 |
(MPEG-21) |
Multimedia Framework
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Part 1 |
Vision, Technologies and
Strategy |
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Part 2 |
Digital Item Declaration
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Part 3 |
Digital Item Identification |
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Part 4 |
IPMP Components |
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Part 5 |
Rights Expression Language
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Part 6 |
Rights Data Dictionary
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Part 7 |
Digital Item Adaptation
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Part 8 |
Reference Software
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Part 9 |
File Format |
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Part 10 |
Digital Item Processing
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Part 11 |
Evaluation Tools for
Persistent Association |
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Part 12 |
Test Bed for MPEG-21
Resource Delivery |
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Part 13 |
VOID - (to MPEG-4 part 10)
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Part 14 |
Conformance |
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Part 15 |
Event reporting |
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Part 16 |
Binary format |
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Part 17 |
Fragment Identification
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Part 18 |
Digital Item Streaming
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- Part 1 Vision, Technologies and Strategy lays down the scope and development plan of the project.
- Part 2 Digital Item Declaration
(DID) defin es a structure that can flexibly accommodate the many
components of a multimedia object (resources, identifiers, metadata,
encryption keys, licenses etc.).
- Part 3 Digital Item Identification (DII), a standard to handle identifiers in Digital Items.
- Part 4 Intellectual Property Management and Protection (IPMP) Components
specifies the component technologies to make elements of a Digital
Item available in a form that can be processed by a machine.
- Part 5 Rights Expression Language (REL)
defines a language to express machine readable rights in a rich form
that is comparable to the richness of the human language.
- Part 6 Rights Data Dictionary (RDD)
defines a standard semantics for verbs commonly used in the media
environment, especially for use by Part 5..
- Part 7 Digital Item Adaptation (DIA) specifies the syntax and semantics of the tools that may be used to assist in the adaptation of Digital Items, metadata and resources.
- Part 8 Reference Software
provides the reference software implementation of the relevant MPEG-21
standards.
- Part 9 File Format
defines a standard file format for Digital Items.
- 10 Digital Item Processing
(DIP) provides the tools to enable a Digital Item creator to suggest
how a user can interact with the Digital Item.
- Part 11 Evaluation Tools for Persistent Association provides the means to evaluate the performance of a given
Persistent Association Technology to see how well it fulfils the requirements of the intended application.
- Part 12 Test Bed for MPEG-21 Resource Delivery
is a software test bed that has been developed to enable
experimentation with different means of resource delivery.
- Part 14 Conformance provides test methodologies and suites to assess the conformity of a bitstream (typically an XML document) and a decoder (typically a parser) to the relevant MPEG-21 standard.
- Part 15 Event Reporting (ER)
provides the technology to generate an event every time an action specified in the “Event Report Request” (ERR) contained in a Digital Item is made on a resource.
- Part 16 Binary format references the
technology specified in MPEG-B Part 1 “Binary MPEG format for XML” (BiM).
- Part 17 Fragment Identification (FID) specifies a normative syntax for URI Fragment Identifiers to be used for addressing parts of a resource from a number of Internet Media Types.
- Part 18
Digital Item Streaming (DIS) provides the technology to achieve this when the streaming mechanism employed is MPEG-2 Transport Stream and RTP/UDP/IP.
6. MPEG-A (ISO/IEC 23000)
The
current table of MPEG-A standards is
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23000 |
(MPEG-A) |
Multimedia Application
Formats |
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Part 1 |
Purpose for Multimedia
Application formats |
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Part 2 |
Music Player Application
Format |
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Part 3 |
Photo Player Application
Format |
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Part 4 |
Musical Slide Show
Player Application Format |
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Part 5 |
Media Streaming Application Format |
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Part 6 |
Professional Archival
Application Format |
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Part 7 |
Open Access
Application Format |
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Part 8 |
Portable Video Player
Application Format |
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Part 9 |
Digital Multimedia
Broadcasting Application Format |
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Part 10 |
Video Surveillance
Application Format |
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Part 11 |
Stereoscopic
Video Application Format |
- Part 1 Vision, Technologies and Strategy down the scope and development plan of the
MPEG-A project.
- Part 2 “Music Player Application Format” enables an augmented experience of sound resources by providing an “extended MP3 format”.
- Part 3 “Photo Player Application Format”
enables an augmented experience of their photo resources by adding more information to the ubiquitous JPEG File Format, namely
- Part 4 “Musical Slideshow Application Format” builds on top of the Music Player and the Photo Player Application Formats and is a superset of these two Application Formats.
- Part 5 “Media Streaming Application Format” specifies how to use specific MPEG technologies to build a full-fledged media player for streaming governed content.
- Part 6 “Professional Archival Application Format” provides a standard packaging format for carriage of digital multimedia content, metadata to describe context information related to digital multimedia content
and the logical structure of how the digital multimedia content is stored,
identification of processing tools and data protection and integrity tools, data governance tools, and data compression tools.
- Part 7 “Open Access Application Format” defines a format designed for users who own rights to a piece of content and have an interest in releasing it in such a way that other users can freely access it but without making it public domain.
- Part 8 “Portable Video Application Format” defines a format for the use of video files on portable devices giving users the possibility to use the content interactively.
- Part 9 “Digital Multimedia Broadcasting Application Format” defines a standard file format that can be used to store in and exchange DMB content between DMB terminals.
- Part 10 “Video Surveillance Application Format” provides a lightweight wrapper to the video content from the MPEG technologies, video coding, related metadata and file format, suitable for video surveillance.
- Part 11 “Video Stereoscopic Application Format”
enables more realistic experiences (with or without special glasses).
7. MPEG-B (ISO/IEC 23001)
The
current table of MPEG-B standards is
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23001 |
(MPEG-B) |
MPEG Systems Technologies |
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Part 1 |
Binary MPEG format for XML |
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Part 2 |
Fragment Request Unit |
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Part 3 |
XML
Representation of IPMP-X messages |
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Part 4 |
Codec Configuration Representation |
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Part 5 |
Bitstream Syntax
Description Language |
- Part 1 “Binary MPEG format for XML” (BiM) provides a standard set of generic technologies to transmit and compress XML documents, addressing a broad spectrum of applications and requirements.
- Part 2 “Fragment Request Unit” specifies a technology enabling a terminal to request XML fragments of immediate interest.
- Part 3 “XML Representation of IPMP-X Messages” provides an XML representation of the IPMP-X messages defined in MPEG-4 part 13 with extensions.
- Part 4 “Codec Configuration Representation” provides a compressed digital representation of a video decoder and of the corresponding bitstream, assuming that the receiving terminal shares a library of video coding tools with the transmitter.
- Part 5 “Bitstream Syntax Description Language” provides a normative grammar to describe, in XML, the high-level syntax of a bitstream.
8. MPEG-C (ISO/IEC 23002)
The
current table of MPEG-C standards is
|
23002 |
(MPEG-C) |
MPEG Video Technologies |
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Part 1 |
Accuracy specification for
implementation of integer-output IDCT |
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Part 2 |
Fixed point implementation
of DCT/IDCT |
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Part 3 |
Auxiliary Video Data
Representation |
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Part 4 |
Video Tool Library |
- Part 1 “Accuracy specification for implementation of integer-output IDCT” specifies the IDCT accuracy that is equivalent to or extends the IEEE 1180 standard which has been withdrawn.
- Part 2 “Fixed-point 8x8 inverse discrete cosine transform and discrete cosine transform” specifies a particular fixed-point approximation to the ideal 8x8 IDCT and DCT function, fulfilling the 8x8 IDCT conformance requirements for the MPEG-1, MPEG-2 and MPEG-4 part 2 video coding standards.
- Part 3 “Auxiliary Video Data Representation” specifies how auxiliary data such as pixel-related depth or parallax values, are to be represented when encoded by MPEG video standards in the same way as ordinary picture data.
- Part 4 “Video Tool Library” contains a collection of descriptions of video coding tools, called Functional Units, as referenced in MPEG-B Part 4.
9. MPEG-D (ISO/IEC 23003)
The
current table of MPEG-D standards is
|
23003 |
(MPEG-D) |
MPEG Audio Technologies |
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Part 1 |
MPEG Surround |
Part 1 “MPEG Surround” provides an efficient bridge between stereo and multichannel presentations in low-bitrate applications
by supporting very efficient parametric coding of multi-channel audio signals, so as to permit transmission of such signals over channels that typically support only the transmission of stereo (or even mono) signals.
10. MPEG-E (ISO/IEC 23004)
The
current table of MPEG-E standards is
|
23004 |
(MPEG-E) |
MPEG Multimedia Middleware |
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Part 1 |
Architecture |
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Part 2 |
Multimedia API |
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Part 3 |
Component Model |
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Part 4 |
Resource and Quality
Management |
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Part 5 |
Component Download |
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Part 6 |
Fault Management |
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Part 7 |
System Integrity Management |
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Part 7 |
Reference Software and
Conformance |
- Part 1 “Architecture” describes the M3W architecture and APIs.
- Part 2 “Multimedia API” specifies access to the functionalities provided by conforming multimedia platforms such as Media Processing Services (including coding, decoding and trans-coding), Media Delivery Services (through files, streams, messages), Digital Rights Management (DRM) Services, Access to data (e.g. media content) and Access to, Edit and Search Metadata.
- Part 3 “Component Model” specifies a technology enabling cost effective software development and an increase in productivity through software reuse and easy software integration.
- Part 4 “Resource and Quality Management” specifies a framework for resource management aiming to optimise and guarantee the Quality of Service that is delivered to the end-user in a situation where resources are constrained.
- Part 5 “Component Download” specifies a download framework enabling controlled download of software components to a device.
- Part 6 “Fault Management” specifies a framework for fault management with the goal to have a dependable/reliable system in the context of faults. These can be introduced due to upgrades and extensions out of the control of the device vendor, or because it is impossible to test all traces and configurations in today’s complex software systems.
- Part 7 “System Integrity Management” specifies a framework for integrity management with the goal to have controlled upgrading and extension, in the sense that there is a reduced chance of breaking the system during an upgrade/extension or to provide the ability to restore a consistent configuration.
- Part 8 “Reference Software and Conformance” is the usual complement as with the other MPEG standards.
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