[November 07, 2000] MPEG-7 is an ISO/IEC standard developed by MPEG (Moving Picture Experts Group). The syntax for the associated Description Definition Language (DDL) is XML. "The Description Definition Language (DDL) is the language which allows the creation of MPEG-7 Description Schemes and Descriptors. A DDL schema (a DDL file) specifies the constraints that a valid MPEG-7 description should respect. It is encoded in XML. The DDL is used by MPEG-7 groups when they have to define any structured data model. For instance the MDS, audio and video groups are using it to define their descriptors and description schemes."
Overview: "The Moving Picture Coding Experts Group (MPEG) is a working group of ISO/IEC in charge of the development of international standards for compression, decompression, processing, and coded representation of moving pictures, audio and their combination. MPEG has started work on a new standard known as MPEG-7: a content representation standard for information search, scheduled for completion in Fall 2001. The Call for Proposals was issued in October 1998. MPEG-7 is not aimed at any one application in particular; rather, the elements that MPEG-7 standardises shall support as broad a range of applications as possible."
"The main tools used to implement MPEG-7 descriptions are the Description Definition Language (DDL), Description Schemes (DSs), and Descriptors (Ds). Descriptors bind a feature to a set of values. Description Schemes are models of the multimedia objects and of the universes that they represent e.g. the data model of the description. They specify the types of the descriptors that can be used in a given description, and the relationships between these descriptors or between other Description Schemes The DDL forms a core part of the MPEG-7 standard. It provides the solid descriptive foundation by which users can create their own Description Schemes and Descriptors. The DDL defines the syntactic rules to express and combine Description Schemes and Descriptors. The DDL must satisfy the MPEG-7 DDL requirements. It has to be able to express spatial, temporal, structural, and conceptual relationships between the elements of a DS, and between DSs. It must provide a rich model for links and references between one or more descriptions and the data that it describes. It also has to be capable of validating descriptor data types, both primitive (integer, text, date, time) and composite (histograms, enumerated types). In addition, it must be platform and application independent and human- and machine-readable. The general consensus within MPEG-7 is that it should be based on XML syntax."
"The DDL design has been informed by numerous proposals and input documents submitted to the MPEG-7 DDL AHG since the MPEG-7 Call for Proposals in October 1998. It has also been heavily influenced by W3C's XML Schema Language and the Resource Description Framework (RDF). At the 51st MPEG meeting in Noordwijkerhout in March 2000, it was decided to adopt XML Schema Language as the MPEG-7 DDL. However the DDL will require some specific extensions to XML Schema Language to satisfy all of the requirements of MPEG-7. Some of the required extensions are described here. However their precise implementation is still being investigated and further extensions may be required."
"MPEG-7 Extensions to XML Schema. The following features will need to be added to the XML Schema Language specification in order to satisfy specific MPEG-7 requirements : Parameterized array sizes; Typed references ; Built-in array and matrix datatypes; Enumerated datatypes for MimeType, CountryCode, RegionCode, CurrencyCode and CharacterSetCode. MPEG-7-specific parsers will be developed by adding validation of these additional constructs to standard XML Schema parsers..." [from the May/June 2000 "Overview" document]
[November 07, 2000] "MPEG-7 Behind the Scenes." By Jane Hunter (Distributed Systems Technology Centre University of Queensland). In D-Lib Magazine [ISSN: 1082-9873] Volume 5 Number 9 (September 1999). ['The purpose of this article is to provide a better understanding of the objectives and components of the MPEG-7, 'Multimedia Content Description Interface' standard, an overview of the current state of its development and an idea of its expected impact on digital libraries of the future.'] "MPEG-7 is being developed by the Moving Pictures Expert Group (MPEG), a working group of ISO/IEC. Unlike the preceding MPEG standards (MPEG-1, MPEG-2, MPEG-4) which have mainly addressed coded representation of audio-visual content, MPEG-7 focuses on representing information about the content, not the content itself. The goal of the MPEG-7 standard, formally called the "Multimedia Content Description Interface", is to provide a rich set of standardized tools to describe multimedia content. A single standard which can provide a simple, flexible, interoperable solution to the problems of indexing, searching and retrieving multimedia resources will be extremely valuable and widely deployed. Resources described using such a standard will acquire enhanced value. Compliant hardware and software tools capable of efficiently generating and interpreting such standardized descriptions will be in great demand... MPEG-7 is intended to describe audiovisual information regardless of storage, coding, display, transmission, medium, or technology. It will address a wide variety of media types including: still pictures, graphics, 3D models, audio, speech, video, and combinations of these (e.g., multimedia presentations). Examples of MPEG-7 data are an MPEG-4 stream, a video tape, a CD containing music, sound or speech, a picture printed on paper, or an interactive multimedia installation on the web. MPEG-7 will address both retrieval from digital archives (pull applications) as well as filtering of streamed audiovisual broadcasts on the Internet (push applications). It will operate in both real-time and non real-time environments. A "real-time environment" in this context means that the description is generated at the same time as the content is being captured (e.g., smart cameras and scanners)... The Description Definition Language (DDL) is the language that allows the creation of new Description Schemes and Descriptors. It also allows the extension and modification of existing Description Schemes. The DDL has to be able to express spatial, temporal, structural, and conceptual relationships between the elements of a DS, and between DSs. It must provide a rich model for links and references between one or more descriptions and the data that it describes. It also has to be capable of validating descriptor data types, both primitive (integer, text, date, time) and composite (histograms, enumerated types). In addition, it must be platform and application independent and human- and machine-readable. The general consensus within MPEG-7 is that it should be based on XML syntax. Of the ten DDL submissions which responded to the CfP in February, one was based on the Synchronized Multimedia Integration Language (SMIL), three were based on XML DTDs, three were based on XML DTDs with extensions such as data typing and inheritance, two were based on the Resource Description Framework (RDF) and one proposal was based on Open Knowledge Base Connectivity (OKBC). After evaluating the DDL proposals, the recommendation was that -- although none of the proposals satisfied all of the requirements, the proposal from DSTC provided the best starting point for further DDL development. However, it was also recommended that the DDL group should track the work of the W3C -- in particular, the XML Schema Working Group and the XLink, XPath and XPointer Working Groups. In May this year, the XML Schema WG produced a 2-part working draft of the XML Schema language: XML Schema Part 1: Structures and XML Schema Part 2 : Datatypes. Discussions and preliminary encoding of the Generic Audiovisual DS led the DDL group to the decision to use XML Schema language as the basis for the DDL. However, certain reservations were raised at the Vancouver MPEG meeting in July concerning this approach. The major concerns were: (1) MPEG-7's dependency on the output and time schedule of W3C XML Schema WG; (2) Restricted access to internal documents associated with XML Schema development; (3) The effect of W3C's copyright of XML Schema language on the ability to add MPEG-7-specific extensions. As a result of these concerns, further discussions at the Vancouver meeting led to the decision to develop an MPEG-7-specific language in parallel with the XML Schema development being carried out within W3C. A new grammar based on DSTC's proposal, but using MPEG-7 terminology (Description Schemes and Descriptors) and with modifications to ensure simple mapping to XML Schema, was recently developed. Based on this grammar, the following tasks are currently being performed: (1) Specification of the BNF and an XML DTD for the new grammar; (2) Specification of the validation mechanisms which must be provided by a parser; (3) Development of a validating parser for this DDL. MPEG-7 is aware of, and taking into account, the activities of a number of other standards groups during the development process. For the archival descriptions, library (e.g., MARC, Z39.50) and archive (e.g., EBU/SMPTE, ISAD(G), EAD, Dublin Core, CEN/ISSS MMI) standards are being taken into account. Whilst for the streaming descriptions, the broadcast Electronic Programme Guides (EPGs) (e.g., DVB, ATSC) and web channels (Channel Definition Format (CDF)) standards are being considered. For the intellectual property and rights management descriptions, a liaison has been formed with the INDECS project. The DDL group has been closely monitoring the work of the W3C's XML Schema Working Group and the XLink, XPath and XPointer Working Groups. The MPEG-7 community is attempting to combine efforts with these groups through liaisons." [cache]
References:
Overview of the MPEG-7 Standard. ISO/IEC JTC1/SC29/WG11 N4031. March 2001.
MPEG-7 DDL Working Draft 4.0. ISO/IEC JTC1/SC29/WG11 N3575, MPEG 00/N3575. Edited by Jane Hunter (DSTC Pty Ltd). Beijing, July 2000. "At the 51st MPEG meeting in Noordwijkerhout, it was decided to adopt XML Schema Language with MPEG-7-specific extensions as the MPEG-7 DDL. Consequently this document has been rewritten to reflect this decision. It provides an overview of the most important features of XML Schema, from the point of view of satisfying MPEG-7 requirements. In addition it describes MPEG-7-specific extensions, perceived problems with XML Schema Language and DDL open issues... In addition to the built-in derived types provided by XML Schema:Datatypes, the following built-in enumerated data types will be provided: (1) MimeType - IANA list of Mime Types (type= IANA-MimeType); (2) Country Code - ISO3166-1:1997 (type="ISO3166-1CountryCode"); (3) Region Code - ISO3166-2:1998 (type="ISO3166-2RegionCode"); (4) Currency Code - ISO4217:1995 (type="ISO4217CurrencyCode"); (5) Character Set Code - IANA List of Character Sets (type="IANA-CharacterSetCode")." [cache]
MPEG-7 Description Definition Language (DDL) - XML Schema Problem Issues and Requests. "This list has been compiled through an evaluation of the XML Schema Language's ability to satisfy MPEG-7. It is based on the following W3C April 7, 2000 WDs..." [cache]
DDL mailing list: mpeg7-ddl@darmstadt.gmd.de
mpeg-industry.com. MPEG-7 resources
See also: "MPEG-21 Part 2: Digital Item Declaration Language (DIDL)." Draft 2001-03: MPEG-21, Part 2. Digital Item Declaration Working Document (2.0).
[December 16, 2003] "An Analysis of XML Database Solutions for the Management of MPEG-7 Media Descriptions." By Utz Westermann and Wolfgang Klas (University of Vienna). In ACM Computing Surveys (CSUR) Volume 35, Issue 4 (December 16, 2003), pages 331 - 373. [ISSN: 0360-0300] "MPEG-7 constitutes a promising standard for the description of multimedia content. It can be expected that a lot of applications based on MPEG-7 media descriptions will be set up in the near future. Therefore, means for the adequate management of large amounts of MPEG-7-compliant media descriptions are certainly desirable. Essentially, MPEG-7 media descriptions are XML documents following media description schemes defined with a variant of XML Schema. Thus, it is reasonable to investigate current database solutions for XML documents regarding their suitability for the management of these descriptions. In this paper, we motivate and present critical requirements for the management of MPEG-7 media descriptions and the resulting consequences for XML database solutions. Along these requirements, we discuss current state-of-the-art database solutions for XML documents. The analysis and comparison unveil the limitations of current database solutions with respect to the management of MPEG-7 media descriptions and point the way to the need for a new generation of XML database solutions... For the management of MPEG-7 media descriptions (and certainly for the management of other data-centric XML documents as well, e.g., in the domain of electronic interchange of business data), we therefore see the need for a new generation of XML database solutions which recognize the central importance of exploiting the type information contained in schema definitions for the adequate management of XML documents. At the same time, these solutions should not neglect other important issues such as sophisticated (multidimensional) value, text, and path index structures, profound extensibility with custom functionality and index structures, and -- not to forget these -- classic DBMS functionality such as transactions, fine-grained concurrency and access control, and reliable means for backup and recovery. It seems that the necessity of using schema definitions to achieve an adequate management of XML documents is to becoming more and more recognized. As a newer XML database solution, Oracle XML DB/Structured Mapping already to some extent makes use of schema defi- nitions written in XML Schema for document validation and for the typing of basic document contents, as well as for query optimization. At least for the management of MPEG-7 media descriptions, however, the system has to be developed further to overcome its limitations with regard to the more complicated constructs of MPEG-7 DDL/XML Schema in order to be considered more than just a harbinger of a new generation of schema-aware XML database solutions." See also: (1) "A Typed Representation and Type Inference for MPEG-7 Media Descriptions"; (2) "An Analysis of XML Database Solutions Concerning the Management of MPEG-7 Media Descriptions" (Technical Report, No. TR-2002302, Dept. of Computer Science and Business Informatics, University of Vienna, September, 2002).
[August 21, 2002] "Queries of Digital Content Descriptions in MPEG-7 and MPEG-21 XML Documents." By Peiya Liu and Liang H. Hsu (Siemens Corporate Research, Inc). Paper presents at the XML Europe 2002 Conference, Barcelona, Spain. "The paper shows certain critical query specification issues for MPEG-7 and MPEG-21 XML documents and illustrates a logic method to handle the limitations in current text-oriented XML query languages for retrieving multimedia content and digital items... MPEG-7 is an emergent ISO/IEC standard and formally named as "Multimedia Content Description Interface". Unlike the previous MPEG[MPEG Web Site] compression standards MPEG-1, MPEG-2 and MPEG-4, MPEG-7 aims to create a standard for describing the multimedia content to enable the integration of production, distribution and content access paradigm. This MPEG-7 standard uses an XML Schema to describe multimedia objects such as video, audio images, etc. as spatial, temporal or visual XML datatypes. This type of multimedia XML documents may include descriptions about both static/spatial media (such as text, drawings, images, etc.) and time-based media (such as video, audio, animation,etc.). The content can be further organized into three major document structures: hierarchical, hyperlinked, and temporal/spatial structures. A related ISO/IEC standard MPEG-21 is defining a multimedia framework to support the content delivery chain. This multimedia content delivery chain encompasses content creation, production, delivery and consumption. To support this, several key elements have identified: digital item declaration, identification, description, content handling, intellectual property management, digital item rights management, etc. Digital items are defined as structured digital objects, including representation, identification and metadata description. This paper will focus on two types of MPEG-21 XML documents (Digital Item Declaration, and Digital Item Identification and Description) and illustrate the relationships to MPEG-7 XML documents for digital content and item queries. MPEG-7 and MPEG-21 standards have posed an interesting challenge to XML query language design in covering different XML aspects. This paper shows some critical specification issues in forming MPEG-7 and MPEG-21 XML queries. In addition, a logic formalism called Path Predicate Calculus is illustrated to handle the limitations in current text-oriented XML query languages for multimedia XML queries. In this formalism, the atomic logic formulas are element predicates rather than relation predicates in relational calculus. The queries describe a desired document tree by specifying path predicates that the tree document elements must satisfy. Spatial, temporal and visual datatypes and relationships can also be described in this formalism for content retrieval and identification in MPEG-7 and MPEG-21 XML documents..." Also available in PDF format. [cache]
[August 26, 2002] IBM Multimodal Annotation Tool Supports Video and Audio Annotations for MPEG-7 Files. IBM alphaWorks has released the IBM Multimodal Annotation Tool, which "assists in annotating MPEG files with MPEG-7 meta data. It provides the means for annotating three different multimodal types: video, audio with video, or audio without video. Each shot in the video sequence can be annotated with static scene descriptions, key object descriptions, event descriptions, and other lexicon sets. Audio segments can be delimited and described as well. The annotated descriptions are stored as MPEG-7 descriptions in an XML file. The IBM Multimodal Annotation Tool can also open MPEG-7 files in order to display the annotations for the corresponding MPEG file. This tool also allows customized lexicons to be created, saved, downloaded, and updated. The IBM Multimodal Annotation Tool takes an MPEG file as the required input source. The tool also requires a corresponding shot segmentation file, where the video sequence input is segmented into smaller units, called video shots, by detecting the scene cuts, dissolutions, and fadings. This shot file can be loaded into the tool from other sources. The installation kit for the tool contains the NIST TREC-2002 Video Track shot files converted to the tool's format. As an alternative, the shot file can also be generated by the IBM CueVideo Shot Detection Tool Kit or the IBM MPEG-7 Annotation Tool (also present on alphaWorks) and used directly by the tool. " See also the "IBM MPEG-7 Annotation Tool Supports XML Metadata Description" (tool for annotating video sequences with MPEG-7 metadata).
[April 20, 2002] "Combining the CIDOC CRM and MPEG-7 to Describe Multimedia in Museums." By Jane Hunter (DSTC [Distributed Systems Technology Centre] Pty Ltd, University of Qld, Australia). Paper presented at Museums and the Web 2002 Conference, 'Standards in Action' section. 20 pages, with 21 references. "This paper describes a proposal for an interoperable metadata model, based on international standards, which has been designed to enable the description, exchange and sharing of multimedia resources both within and between cultural institutions. Domain-specific ontologies have been developed by two different ISO Working Groups to standardize the semantics associated with the description of museum objects (CIDOC Conceptual Reference Model) and the description of multimedia content (MPEG-7) -- but no single ontology or metadata model exists for describing museum multimedia content. This paper describes an approach which combines the domain-specific aspects of MPEG-7 and CIDOC-CRM models into a single ontology for describing and managing multimedia in museums. The result is an extensible model which could lead to a common search interface and the open exchange, sharing and integration of heterogeneous multimedia resources distributed across cultural institutions... Based on the proposals described here, an RDF Schema representation of the MPEG-7 extensions to the CIDOC CRM, has been developed and is available [see: RDF Schema Representation of the MPEG-7 Extensions to the CIDOC CRM] ... [we analyze] the strengths and weaknesses of the CIDOC CRM and MPEG-7 ontologies in the context of providing a metadata model for describing and managing museum multimedia resources. Based on this analysis, we describe an approach to merging the two models which involves using the CIDOC CRM as the underlying foundation and extending it through the addition of MPEG-7-specific sub-classes and sub-properties to provide support for multimedia concepts and descriptions. The outcome is a single machine-understandable ontology (in RDF Schema) which can be used to provide the underlying model for describing multimedia in museums and thus facilitate the exchange, sharing and integration of heterogeneous multimedia information between cultural institutions." Note: the paper references other important work on MPEG-7, including Hunter's "Adding Multimedia to the Semantic Web - Building an MPEG-7 Ontology" (PDF, also in HTML). [cache PDF, RDF Schema.
[January 08, 2002] "MPEG-7 Alliance Pushes the Standard for Multimedia Content Description." - The Moving Picture Expert Group (MPEG) has announced the "launch of the MPEG-7 Alliance, a focus group of industry and academic experts. The main objective of the alliance is to act as an interface between MPEG, industry and academic organisations to promote the adoption of MPEG-7, the metadata standard for the description of audio-visual content. Based largely on XML schema, the MPEG-7 standard is designed to facilitate the archiving, searching and browsing of multimedia content on the web or any online database, and has recently achieved FDIS (final draft of international standard) status. The MPEG-7 Alliance (MP7A), held its first official meeting on 8-December-2001 in Pattaya, Thailand. The focus of the meeting was to bring together the creators of the MPEG-7 standard and potential users in order to forge working partnerships to use, promote and develop the MPEG-7 standard. The meeting was well attended with 39 attendees from over 30 organisations, including people from organisations such as Reuters, Sony, Hitachi, Samsung, LG Electronics, IBM, Fujitsu, Sharp, Mitsubishi, Canon, Panasonic and Siemens. MPEG-7 enables users to search for multimedia content as easily as text-only files. The key lies in providing a flexible and extensible framework for describing audio-visual data, providing description tools that are based on catalogue, semantic and structural features of the content. Examples of the technology created by MPEG-7 working groups include visual tools to search images by colour, textural patterns, or by certain objects and shapes, such as specific logo designs. Searches by motion trajectory -- which are especially useful in remote surveillance systems -- and queries-by-humming/melody clips, and spoken sentences are also possible. The strength of MPEG-7 lies in its open-standards technology. This ensures maximum interoperability with other leading audio-visual standards groups and consortia. The XML-based standard also creates an attractive environment for content creators, distributors, content-management vendors and start-up enterprises already familiar with metadata technologies... Moving Picture Experts Group (MPEG) is a working group of ISO/IEC in charge of the development of standards for coded representation of digital audio and video. Established in 1988, the group has produced MPEG-1 the standard on which such products as Video CD and MP3 are based, MPEG-2, the standard on which such products as Digital Television set top boxes and DVD are based, MPEG-4, the standard for coding multimedia objects and applicable to the fixed and mobile web and MPEG-7, the standard for description of audio and visual content. Work on the new standard MPEG-21 'Multimedia Framework' was started in June 2000."
[November 20, 2001] "MPEG-7 Tackles Multimedia Content." By Neil Day (President, MPEG Industry Forum, Sunnyvale, CA). In EE Times (November 12, 2001). "The September 2001 debut of the MPEG-7 standard heralds a new wave of applications for managing the exponential growth and distribution of multimedia content such as content over the Internet, digital broadcast networks and home databases. MPEG-7 makes searching the Web for multimedia content as easy as searching for text-only files. The MPEG-7 standard will prove particularly useful in large-content archives, which the public can now access, and in multimedia catalogs in which consumers identify content for purchase. Content-retrieval information may also be used by agents, for the selection and filtering of broadcast "push" material or for personalized advertising. Further, MPEG-7 descriptions will allow fast and cost-effective use of the underlying data, by enabling semiautomatic multimedia presentation and editing. In essence, MPEG-7 is the metadata standard, based on XML Schema, for describing features of multimedia content and providing the most comprehensive set of audio-visual description tools available. These description tools are based on catalog (title, creator, rights); semantic (the who, what, when and where information about objects and events); and structural (the measurement of the amount of color associated with an image or the timbre of a recorded instrument) features of the audio-visual content. They build on the audio-visual data representation defined by MPEG-1, -2 and -4... MPEG-1, -2 and -4 make content available. MPEG-7 lets you to find the content you need. Because of that, it's important to note that MPEG-7 addresses many different applications in many different environments. It provides a flexible and extensible framework for describing audio-visual data, by defining a multimedia library of methods and tools. It standardizes: (1) A set of descriptors. A descriptor is a representation of a feature that defines the syntax and semantics of the feature representation. (2) A set of description schemes. A description scheme specifies the structure and semantics of the relationships between its components, which may be both descriptors and description schemes. (3) A language that specifies description schemes, the Description Definition Language (DDL). It also allows for the extension and modification of existing description schemes. MPEG-7 adopted XML Schema Language as the MPEG-7 DDL. However, the DDL requires some specific extensions to XML Schema Language to satisfy all the requirements of MPEG-7. These extensions are being discussed through liaison activities between MPEG and W3C, the group standardizing XML. (4) A binary representation to encode descriptions. A coded description is one that's been encoded to fulfill relevant requirements such as compression efficiency, error resilience and random access..."
[July 2001] "MPEG-7: The Standard for Describing Rich Content." By Neil Day. In XML Journal Volume 2, Issue 7 (July 2001). "MPEG, through the MPEG-7 Industry Focus Group (www.mpeg-7.com), has announced the third MPEG-7 Awareness Event (AE3), to be held in Washington, DC, on October 27, 2001. This year's event will be especially significant since it occurs during the launch of the ISO's (International Organization for Standardization) newest multimedia standard, MPEG-7. MPEG-7, the Multimedia Content Description Interface Standard, is the standard for rich descriptions of multimedia content, enabling highly sophisticated management, search, and filtering of that content. MPEG-7 offers comprehensive nonproprietary solutions (using XML Schema as its content description language), while being interoperable over multiple platforms and enabling data exchange with standards such as Dublin Core (www.dublincore.org) and TV-Anytime. MPEG-7 provides the solutions needed for managing the exponential growth (see Figure 1) and distribution of multimedia content (e.g., over the Internet, digital broadcast networks, and [home] databases). MPEG-7 uses a Description Definition Language (DDL) to allow the creation of Description Schemes (DSs) and Descriptors (Ds) for rich multimedia content. These descriptions are based on catalog (i.e., title, creator, rights), semantic (i.e., the who, what, when, and where information about objects and events), and .structural (i.e., the color histogram - measurement of the amount of color associated with an image or the timbre of a recorded instrument) features of the AV content. The DDL defines the syntactic rules to express and combine Description Schemes and Descriptors. A DDL file is encoded in XML and more specifically uses the constructs defined in the W3C's XML Schema Language... The main recommendation of the MPEG-7 community was to use a schema language based on XML for the DDL. The stability of the XML Schema language, its potential wide-spread adoption, availability of tools and parsers, and its ability to satisfy the majority of MPEG-7's requirements led to the decision to adopt XML Schema as the basis for the DDL... A prototype pure MPEG-7 parser has been recently developed by a French company, Expway (contact: Claude.Seyrat@acland.fr). This parser is based on the Xerces open-source XML Schema parser..." [alt URL]
[April 09, 2001] On BiM. Claude Seyrat wrote on XML-DEV in response to 'there seems to be a binary representation of XML done in the MPEG-7 work...': "Indeed, the MPEG consortium is working on such binary encoding of XML documents for the future MPEG-7 standard. The binary encoding uses XML Schema definitions to generate an highly compressed encoding schemes. Structure is coded when it is needed (optional elements) and data are coded in 'natural format' i.e., integers are carried as 2's complement integers, float as IEEE 754, etc... BiM parsers can provide an enhanced SAX API. Moreover the format (called BiM) allows skipping of undesired elements and dynamic updating of XML tree. In two words, MPEG-7 BiM allows compression and streaming of XML files. Do not hesitate to contact me for further information, I'm currently preparing web pages on that subject."
[June 2000] "MPEG-7: Daring to Describe Multimedia Content." By Neil Day. In XML Journal Volume 1, Issue 6 (June 2000). "MPEG-7 provides the world's most comprehensive set of audiovisual descriptions. These descriptions are based on the catalog (title, creator, rights), semantic (the who, what, when, where information), and structural (the color histogram - measurement of the amount of color - associated with an image or the timbre of a recorded instrument) features of the AV content, and are leveraged on the AV data representation defined by MPEG-1, -2, and -4. MPEG-7 also uses XML Schema as the language of choice for content description. However, MPEG-7 won't standardize the (automatic) extraction of AV descriptions/features. Nor will it specify the search engine (or any other program) that can make use of the description. It's left up to the creativity and innovation of search engine companies to manipulate and massage the MPEG-7-described content into search indexes that can be used by their browser and retrieval tools. It's important to note that MPEG-7 addresses many different applications in many different environments. This means that it needs to provide a flexible and extensible framework for describing audiovisual data. MPEG-7 defines a library of methods and tools for many types of multimedia applications. It standardizes: (1) A set of descriptors: A descriptor (D) is a representation of a feature that defines the syntax and semantics of the feature representation. (2) A set of description schemes: A description scheme (DS) specifies the structure and semantics of the relationships between its components, which may be both descriptors and description schemes. (3) A language that specifies description schemes (and possibly descriptors), the Description Definition Language (DDL): It also allows for the extension and modification of existing description schemes. MPEG-7 adopted XML Schema Language as the MPEG-7 DDL. However, the DDL requires some specific extensions to XML Schema Language to satisfy all the requirements of MPEG-7. These extensions are currently being discussed through liaison activities between MPEG and W3C, the group standardizing XML. (4) One or more ways (textual, binary) to encode descriptions: A coded description is one that's been encoded to fulfill relevant requirements such as compression efficiency, error resilience, and random access..." [alt URL]
