ISO/IEC 15938-6:2003
(Main)Information technology — Multimedia content description interface — Part 6: Reference software
Information technology — Multimedia content description interface — Part 6: Reference software
ISO/IEC 15938-6:2003 is the reference software for ISO/IEC 15938 standard. It implements the normative components of the ISO/IEC 15938 standard, which are the descriptors and description schemes and their coding schemes. Besides this, also informative components are implemented. These are, e.g, the procedures to extract descriptions and to match descriptions. This way, the reference software implements basic functionalities for individual descriptors and description schemes in the so-called key applications. Besides the reference software source code, ISO/IEC 15938-6:2003 gives also a description of the reference software. The components of the key applications and their interfaces are specified.
Technologies de l'information — Interface de description du contenu multimédia — Partie 6: Logiciel de référence
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INTERNATIONAL ISO/IEC
STANDARD 15938-6
First edition
2003-07-01
Information technology — Multimedia
content description interface —
Part 6:
Reference software
Technologies de l'information — Interface de description du contenu
multimédia —
Partie 6: Logiciel de référence
Reference number
ISO/IEC 15938-6:2003(E)
©
ISO/IEC 2003
---------------------- Page: 1 ----------------------
ISO/IEC 15938-6:2003(E)
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© ISO/IEC 2003
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...
INTERNATIONAL ISO/IEC
STANDARD 15938-6
First edition
2003-07-01
Information technology — Multimedia
content description interface —
Part 6:
Reference software
Technologies de l'information — Interface de description du contenu
multimédia —
Partie 6: Logiciel de référence
Reference number
ISO/IEC 15938-6:2003(E)
©
ISO/IEC 2003
---------------------- Page: 1 ----------------------
ISO/IEC 15938-6:2003(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO/IEC 2003
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO/IEC 2003 – All rights reserved
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ISO/IEC 15938-6:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Symbols and abbreviated terms. 1
3 Copyright disclaimer for software modules.2
4 XM software architecture . 2
4.1 Block diagrams . 2
5 Systems reference software (BiM) . 12
5.1 BiM reference software. 12
5.2 Access unit navigator. 14
6 Systems reference software (DDL) . 16
7 Video reference software . 16
8 Audio reference software. 17
9 Multimedia description scheme reference software . 18
10 Compilation of the reference software . 20
11 Usage information for individual descriptors and description schemes. 20
Annex A (informative) Providers of reference software . 21
Annex B (informative) Integration and interface templates . 22
Annex C (informative) Patent statements . 23
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ISO/IEC 15938-6:2003(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
ISO/IEC 15938-6 was prepared by Technical Committee ISO/IEC/TC JTC1, Information technology,
Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information.
ISO/IEC 15938 consists of the following parts, under the general title Information technology — Multimedia
content description interface:
Part 1: Systems
Part 2: Description definition language
Part 3: Visual
Part 4: Audio
Part 5: Multimedia description schemes
Part 6: Reference software
Part 7: Conformance testing
Part 8: Extraction and use of MPEG-7 descriptions
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ISO/IEC 15938-6:2003(E)
Introduction
This International Standard, also known as “Multimedia Content Description Interface”, provides a
standardized set of technologies for describing multimedia content. International Standard addresses a broad
spectrum of multimedia applications and requirements by providing a metadata system for describing the
features of multimedia content.
The following are specified in this International Standard:
• Description schemes (DS) describe entities or relationships pertaining to multimedia content. Description
Schemes specify the structure and semantics of their components, which may be Description Schemes,
Descriptors, or datatypes.
• Descriptors (D) describe features, attributes, or groups of attributes of multimedia content.
• Datatypes are the basic reusable datatypes employed by Description Schemes and Descriptors.
• Systems tools support delivery of descriptions, multiplexing of descriptions with multimedia content,
synchronization, file format, and so forth.
This International Standard is subdivided into eight parts:
Part 1 – Systems: specifies the tools for preparing descriptions for efficient transport and storage,
compressing descriptions, and allowing synchronization between content and descriptions.
Part 2 – Description definition language: specifies the language for defining the standard set of description
tools (DSs, Ds, and datatypes) and for defining new description tools.
Part 3 – Visual: specifies the description tools pertaining to visual content.
Part 4 – Audio: specifies the description tools pertaining to audio content.
Part 5 – Multimedia description schemes: specifies the generic description tools pertaining to multimedia
including audio and visual content.
Part 6 – Reference software: provides a software implementation of the standard.
Part 7 – Conformance testing: specifies the guidelines and procedures for testing conformance of
implementations of the standard.
Part 8 – Extraction and use of MPEG-7 descriptions: provides guidelines and examples of the extraction
and use of descriptions.
This part of ISO/IEC 15938 contains simulation software for tools defined in parts 1, 2, 3, 4 and 5 of
ISO/IEC 15938. This software has been derived from the verification models used in the process of
developing the International Standard.
Where multimedia content extraction or multimedia content description software is provided, attention is called
to the fact that these software modules are provided for the purpose of creating bit streams of descriptors and
description schemes with normative syntax. The performance of these software tools should not be taken as
indicative of that which can be obtained from implementations where quality and computational optimization
are given priority. The techniques used for extracting descriptors or deriving description schemes are not
specified by this document. This information can be found in the corresponding sections of part 1-5.
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INTERNATIONAL STANDARD ISO/IEC 15938-6:2003(E)
Information technology — Multimedia content description
interface —
Part 6:
Reference software
1 Scope
This International Standard operates on and generates conformant bit streams. This International Standard
provides a specific implementation that behaves in a conformant manner. In general, other implementations
that conform to ISO/IEC 15938 are possible that do not necessarily use the algorithms or the programming
techniques of the reference software.
The software contained in this part of ISO/IEC 15938 is known as experimentation software (XM) and is
divided into five categories:
a) Binary format for MPEG-7 (BiM). This software converts DDL (XML) based descriptions to the Binary
format of MPEG-7 and vice versa as explained in Clause 5 of this document.
b) DDL parser and DDL validation parser. The components of this software module are specified in
Clause 6 of this document.
c) Visual descriptors. This software creates standard visual descriptions from associated (visual) media
content as explained in Clause 7 of this document. The techniques used for extracting descriptors are
informative, and the quality and complexity of these extraction tools has not been optimized.
d) Audio descriptors. This software creates standard descriptions from associated (audio) media content
as explained in Clause 8 of this document. The techniques used for extracting descriptors are informative,
and the quality and complexity of these extraction tools has not been optimized.
e) Multimedia description schemes. This software modules provide standard descriptions of Multimedia
Description Schemes as specified in Clause 9 of this document.
2 Symbols and abbreviated terms
For the purposes of this part of ISO/IEC 15938, the following symbols and abbreviated terms apply:
AV: Audio-visual
CS: Coding Scheme
D: Descriptor
Ds: Descriptors
DCT: Discrete Cosine Transform
DDL: Description Definition Language
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ISO/IEC 15938-6:2003(E)
DS: Description Scheme
DSs: Description Schemes
ISO: International Organization for Standardization
MDS: Multimedia Description Schemes
MPEG: Moving Picture Experts Group
MPEG-7: Multimedia Content Description Interface Standard (see ISO/IEC 15938)
XML: Extensible Markup Language
3 Copyright disclaimer for software modules
Each source code module in this specification contains copyright disclaimer which shall not be removed from
the source code module.
In the text of each copyright disclaimer, is replaced with a reference to its associated
specification, e.g. MPEG-7 System (ISO/IEC 15938-1), MPEG-7 Video (ISO/IEC 15938-3), MPEG-7 Audio
(ISO/IEC 15938-4), MPEG-7 Multimedia Description Scheme (ISO/IEC 15938-5).
“This software module was originally developed by () and edited by
(), (), … in the course of development of the . This software
module is an implementation of a part of one or more tools as specified by the
standard>. ISO/IEC gives users of the free license to this software module or modifications
thereof for use in hardware or software products claiming conformance to the . Those
intending to use this software module in hardware or software products are advised that its use may infringe
existing patents. The original developer of this software module and his/her company, the subsequent editors
and their companies, and ISO/IEC have no liability for use of this software module or modifications thereof in
an implementation. Copyright is not released for non conforming products. CN1 retains full
right to use the code for his/her own purpose, assign or donate the code to a third party and to inhibit third
parties from using the code for non conforming products. This copyright notice must be
included in all copies or derivative works. Copyright 200_”.
=First Name, =Last Name, =Company Name
4 XM software architecture
4.1 Block diagrams
In this section you will find some information about the XM software architecture. The block diagrams give
short overviews, and introduce individual components of the XM software. The section also provides a list of
the directory location for each module.
The composing elements of the MPEG-7 Reference Software are characterized by their functionality and by
their interfaces. They can be configured according to what here is referred as “Key Applications”. We can
distinguish from the functional point of view:
• “Extraction Applications” (a description data base is built from a media data base)
• “Search and Retrieval Applications” (a description is compared with the descriptions in a database to
find the one with the lowest distance)
• “Transcoding Applications” (a media data base is converted into another media data base basing on
its description)
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ISO/IEC 15938-6:2003(E)
Extraction Application
Descriptor/
Media Media Extraction Coding Description
AV Decoder Description
Database Data Tool Scheme Database
schemes
MPEG-7 Reference Software MPEG-7 normative Part
NOTE In the block diagram, boxes represent procedural parts, circles represent data structures.
Figure 1 — Schematic diagram of an “Extraction Application” using
the XM reference software modules
Search & Retrieval Application
MPEG- 7 Reference Software
Descriptor/
Description Coding
Description
Database Scheme
schemes
Matching List of Best
MPEG- 7 normative Part
Tool Matches
Query
Descriptor/
Description
schemes
NOTE In the block diagram, boxes represent procedural parts, circles represent data structures.
Figure 2 — Schematic diagram of a “Search and Retrieval Application” using
the XM reference software modules
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ISO/IEC 15938-6:2003(E)
Transcoding Application
MPEG- 7 normative Part
Descriptor/
Description Coding
Description
Database Scheme
schemes
Query
Descriptor/ Matching
Description Tool
schemes
MPEG- 7 Reference Software
Transcoded
Media
Media Transcoder Media
Database
Database
NOTE In the block diagram, boxes represent procedural parts, circles represent data structures.
Figure 3 — Schematic diagram of a “Transcoding Application” using
the XM reference software modules
In the following, the blocks of the “Key Applications” are distinguished. For elements, that are related to a
specific descriptors or description schemes, the interface is given with the example of the DummyType (the
XM integration template and not a normative descriptor).
4.1.1 Media database
The media database contains media files, which are supported as input file by the AV decoders. The database
file which is read from a file, contains one media filename per line. From this media filename all additional
input and output filenames can be derived.
4.1.2 AV decoders
The XM supports the following AV decoders:
• Still image decoders: ImageMagick (Ver.4.*-5.* linked as external library, not included in the XM
reference software distribution)
• MPEG-1, MPEG-2 video decoders: (XM directory: Decoders/MPEG2Dec)
• MPEG-1 video motion vector extractor: (XM directory: Decoders/MPEG2Dec) (It can extract images
and motion vectors)
• 3D Objects: (XM directory: Media) (It reads a 3D object for 3D shape descriptors)
• Key Points: (XM directory: Media) (It reads in a list of key points from a file).
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ISO/IEC 15938-6:2003(E)
4.1.3 Media data
This is the internal XM representation of the raw media data (one class with different structures depending on
the media content type). The class description for media data can be found in the Media XM directory.
4.1.4 Extraction tools
Extraction tools are specific extraction methods defined for each Descriptor and Description Scheme. All these
source file are available in the ExtractionUtilities XM directory. Extraction tools are not normative in the
implementation but they must provide a valid description. The extraction tools extract the descriptions from
media data. Because media data can be very big, the extraction is performed on time entities of the media, i.e.,
if the media is a video, the extraction is done frame by frame. The interface of the DummyType extraction tool
(implementation template) is given below:
//=========================================================================
class DummyTypeExtractionTool: public DescriptorExtractor
{
friend DummyTypeExtractionInterface;
public:
// Null constructor
DummyTypeExtractionTool();
// Also connects the Descriptor (result memnory) to the extraction
// If set to "0" it automatically creates the descriptor
DummyTypeExtractionTool(DummyTypeDescriptorInterfaceABC
*DummyType);
// ID of object type
virtual const UUID& GetObjectID(void);
// Object type name
virtual const char *GetName(void);
// This informs the extractor where the source data comes from
virtual int SetSourceMedia(MultiMediaInterfaceABC* media);
// Pointer where the description is stored
virtual DummyTypeDescriptorInterfaceABC*
GetDescriptorInterface(void);
virtual int SetDescriptorInterface(DummyTypeDescriptorInterfaceABC
*aDummyTypeDescriptorInterface);
// initililaize descriptor and extraction process (input media must be known)
virtual unsigned long InitExtracting(void);
// performs extraction form input media frame by input media frame
virtual unsigned long StartExtracting(void);
// collects descriptor data after all input media frames were processed
virtual unsigned long PostExtracting(void);
// Extraction object must no be used, only its interface is allowd to
// to be used. This function is to get the interface
virtual DummyTypeExtractionInterfaceABC *GetInterface(void);
// access is allowed only by class factories for this
// object. This avoids having to duplicate the
// ID definition in multiple locations. In the future, we may
// have to do this. PLEASE DO NOT USE THESE UNLESS YOU ARE
// IMPLEMENTING A CLASS FACTORY GENERATING THIS OBJECT
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ISO/IEC 15938-6:2003(E)
static const UUID myID;
static const char * myName;
private:
// Destructor is private to allow creation of
// object only by using "new"
virtual ~DummyTypeExtractionTool();
DummyTypeExtractionInterface m_Interface;
DummyTypeDescriptorInterfaceABC *m_DescriptorInterface;
MultiMediaInterfaceABC* m_Media;
// only used in this dummy type to show extraction function
unsigned long m_FrameCnt;
#ifdef __HasSubTypes /*include this section if sub descriptors exist,
remove this section if no sub-descriptors exist*/
SubDummyTypeAExtractionInterfaceABC *m_SubDummyTypeAExtraction;
SubDummyTypeBExtractionInterfaceABC *m_SubDummyTypeBExtraction;
#endif /* __HasSubTypes*/
int m_DummyExtractionParameter;
}; // End class
//=========================================================================
4.1.5 Descriptors (Ds) and Description Schemes (DSs)
These modules implement the data structure of normative Descriptors and Description Schemes. Low level
Video Descriptors are using a dedicated C++ class. This classes provide methods to access the elements of
the normative descriptions. The source files are located in the Descriptors directory. All other normative Ds
and DSs are using the GenericDS class located in the DescriptionSchemes directory. The GenericDS class
does not implement the data structure in a dedicated way, but it is an interface to the XML parser library which
controls the memory for the tree structure of the instantiated D or DS. The interface of the descriptors class is
given for the DummyType descriptor (implementation template) below:
/=========================================================================
class DummyTypeDescriptor: public Descriptor
{
friend DummyTypeDescriptorInterface;
public:
DummyTypeDescriptor();
#ifdef __HasSubTypes /*include this section if sub descriptors exist,
remove this section if no sub-descriptors exist*/
// constructor which also constructs and/or connects the descriptor object
DummyTypeDescriptor(SubDummyTypeADecriptorInterfaceABC *aSubDummyTypeA,
SubDummyTypeBDescriptorInterfaceABC *aSubDummyTypeB);
#endif /* __HasSubTypes*/
virtual const UUID& GetValueID(void);
virtual const char* GetValueName(void);
virtual const UUID& GetObjectID(void);
virtual const char *GetName(void);
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ISO/IEC 15938-6:2003(E)
// for reference counting
virtual void addref();
virtual void release();
#ifdef __HasSubTypes /*include this section if sub descriptors exist,
remove this section if no sub-descriptors exist*/
/* only needed for manual connection with sub components*/
virtual SubDummyTypeADescriptorInterfaceABC
*GetSubDummyTypeADescriptorInterface(void);
virtual unsigned long
SetSubDummyTypeADescriptorInterface(SubDummyTypeADescriptorInterfaceABC
*aSubDummyTypeADescriptorInterface);
virtual SubDummyTypeBDescriptorInterfaceABC
*GetSubDummyTypeBDescriptorInterface(void);
virtual unsigned long
SetSubDummyTypeBDescriptorInterface(SubDummyTypeBDescriptorInterfaceABC
*aSubDummyTypeBDescriptorInterface);
#endif /* __HasSubTypes*/
// actual descriptor methods, only in this dummy type example
virtual long GetDummyContents(void);
virtual void SetDummyContents(const long val);
// transformation to GenericDS object (MDS implementaion style)
virtual unsigned long
ExportDDL(GenericDSInterfaceABC *aParentDescription);
virtual unsigned long ImportDDL(GenericDSInterfaceABC *aDescription);
// access is allowed only by class factories for this
// object. This avoids having to duplicate the
// ID definition in multiple locations. In the future, we may
// have to do this. PLEASE DO NOT USE THESE UNLESS YOU ARE
// IMPLEMENTING A CLASS FACTORY GENERATING THIS OBJECT
static const UUID myID;
static const char * myName;
virtual DummyTypeDescriptorInterfaceABC *GetInterface(void);
private:
// private destructor to force reference counting mechanism
virtual ~DummyTypeDescriptor();
// reference counter
unsigned long m_refcount;
DummyTypeDescriptorInterface m_Interface;
const bool m_isProprietary;
static const char * valName;
static const UUID valID;
#ifdef __HasSubTypes /*include this section if sub descriptors exist,
remove this section if no sub-descriptors exist*/
SubDummyTypeADescriptorInterfaceABC *m_SubDummyTypeADescriptorInterface;
SubDummyTypeBDescriptorInterfaceABC *m_SubDummyTypeBDescriptorInterface;
#endif /* __HasSubTypes*/
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ISO/IEC 15938-6:2003(E)
// This is the actual data the D/DSType stores. In this particular
// dummy example it's just a signed long called m_DummyContents
long m_DummyContents;
};
/=========================================================================
4.1.6 Coding Schemes (CSs)
Coding Schemes are specific coding and decoding methods defined for individual Descriptors and Description
Schemes. All these source file are available in the CodingSchemes directory. If an individual coding schemes
is available, it represents a normative part of the standard. Coding schemes are available for the visual
descriptors to encode or to decode a description into its binary representation. Coding schemes are not
available for Ds and DSs which are implemented using the GenericDS class. In their case, the coding scheme
box is implemented using the GenericDSCS which is an interface to the “write to file”– and “read from file”–
functions of XML parser library. The interface of the coding schemes is given below on the example of the
DummyType coding scheme (implementation template):
//=========================================================================
class DummyTypeCS: public DescriptionCodingEngine
{
friend DummyTypeCSInterface;
public:
DummyTypeCS();
// constructor which also constructs and/or connects the descriptor object
DummyTypeCS(DummyTypeDescriptorInterfaceABC
*DummyType);
virtual const UUID& GetValueID(void);
virtual const char* GetValueName(void);
virtual const UUID& GetObjectID(void);
virtual const char *GetName(void);
// access is allowed only by class factories for this
// object. This avoids having to duplicate the
// ID definition in multiple locations. In the future, we may
// have to do this. PLEASE DO NOT USE THESE UNLESS YOU ARE
// IMPLEMENTING A CLASS FACTORY GENERATING THIS OBJECT
static const UUID myID;
static const char * myName;
virtual DummyTypeCSInterfaceABC *GetInterface(void);
// accessor methods
virtual EncoderFileIO *GetEncoderStreamBuffer(void);
virtual int SetEncoderStreamBuffer(EncoderFileIO *aBuffer);
virtual DecoderFileIO *GetDecoderStreamBuffer(void);
virtual int SetDecoderStreamBuffer(DecoderFileIO *aBuffer);
virtual DummyTypeDescriptorInterfaceABC
*GetDescriptorInterface(void);
virtual int SetDescriptorInterface(DummyTypeDescriptorInterfaceABC
*aDummyTypeDescriptorInterface);
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ISO/IEC 15938-6:2003(E)
//this function writes the description via the encoder buffer to a file
virtual int StartEncode();
//this function reads the description via the decoder buffer from a file
virtual int StartDecode();
private:
// private destructor to allow construction of objects only by “new”
virtual ~DummyTypeCS();
DummyTypeCSInterface m_Interface;
static const char * valName;
static const UUID valID;
// descriptor data
EncoderFileIO *m_EncoderBuffer;
DecoderFileIO *m_DecoderBuffer;
DummyTypeDescriptorInterfaceABC *m_DescriptorInterface;
#ifdef __HasSubTypes /*include this section if sub descriptors exist,
remove this section if no sub-descriptors exist*/
SubDummyTypeACSInterfaceABC *m_SubDummyTypeACS;
SubDummyTypeBCSInterfaceABC *m_SubDummyTypeBCS;
#endif /* __HasSubTypes*/
};
//=========================================================================
4.1.7 Search & Matching Tools
Search tools are specific search, or matching methods defined for each Descriptor and Description Scheme.
All these source file are available in the SearchUtilities XM directory. Matching tools are not normative in the
implementation but they are depending on the specified application of the description.
The search tools can appear in two different ways: for computing distances between descriptions for the
purpose of indexing, and for searching in the descriptions based on a query for the purpose of transcoding.
The interface of the matching tool in the case of distance computation is given with the example of the
DummyType search tools. Here the whole description is processed in one step. The interface of the search
tool for indexing is given below on the example of the DummyType search tool (implementation template):
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ISO/IEC 15938-6:2003(E)
//=========================================================================
class DummyTypeSearchTool: public Search
{
friend DummyTypeSearchInterface;
public:
DummyTypeSearchTool();
// constructor which also constructs and or connects the descriptor object
DummyTypeSearchTool(DummyTypeDescriptorInterfaceABC
...
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