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1、 Reference number ISO/IEC 14496-20:2008(E) ISO/IEC 2008 INTERNATIONAL STANDARD ISO/IEC 14496-20 Second edition 2008-12-01 Information technology Coding of audio-visual objects Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) Technologies de linformati
2、on Codage des objets audiovisuels Partie 20: Reprsentation de scne dapplication allge (LASeR) et format dagrgation simple (SAF) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 00:28:30 MSTNo repr
3、oduction or networking permitted without license from IHS -,-,- ISO/IEC 14496-20:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are lic
4、ensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobes licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of
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6、 to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2008 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 pho
7、tocopying and microfilm, without permission in writing from either ISO at the address below or ISOs 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 copyrightiso.org Web www.iso.org Published in Sw
8、itzerland ii ISO/IEC 2008 All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 00:28:30 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 14496-20:2
9、008(E) ISO/IEC 2008 All rights reserved iii Contents Page Foreword .v Introduction.vii 1 Scope1 2 Normative references2 3 Terms, definitions and abbreviations3 3.1 Terms and definitions.3 3.2 Abbreviations.4 4 Document conventions.4 5 Architecture .4 5.1 Overview.4 5.2 LASeR systems decoder model.5
10、6 Scene representation8 6.1 Overview.8 6.2 Relationship with SVG8 6.3 Timing model .10 6.4 Execution model12 6.5 Events.12 6.6 Encoder configuration16 6.7 LASeR Scene Commands.18 6.8 Scene description elements.31 6.9 Summary of possible attributes per element .47 6.10 Additions to the uDOM API.52 7
11、Simple Aggregation Format (SAF).54 7.1 Overview.54 7.2 Time and terminal model specification.54 7.3 SAF Packet.54 7.4 SAF Packet Header57 7.5 SAF Access Unit57 7.6 SimpleDecoderConfigDescriptor.59 7.7 SimpleDecoderSpecificInfo59 7.8 RemoteStreamHeader.60 7.9 Cache unit 60 7.10 EndOfStream61 7.11 End
12、OfSAFSession.61 7.12 GroupingDescriptor 62 7.13 SAF configuration .62 7.14 Stop cache .63 7.15 SAF Extended Access Unit.64 7.16 SAF first fragment unit64 7.17 SAF fragment unit .65 8 Profiles65 8.1 Overview.65 8.2 LASeR mini 65 8.3 LASeR full.68 8.4 LASeR Core73 9 Compatibility of SAF Packet.76 10 C
13、arriage of LASeR and SAF.77 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 00:28:30 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 14496-20:2008(E) iv ISO/IEC
14、2008 All rights reserved 10.1 Storage of LASeR in MP4 files .77 10.2 Carriage of SAF Streams over HTTP .80 10.3 Carriage of SAF Streams over RTP80 10.4 Carriage of SAF Streams over MPEG-2 Systems.80 11 Electronic attachments .80 12 Binary syntax for the LASeR encoding.81 12.1 Decoding process81 12.2
15、 Binary syntax .86 13 Usage of ISO/IEC 23001-1 .150 13.1 Introduction150 13.2 Electronic attachments .151 13.3 Type codecs.151 13.4 Type codecs for use with ISO/IEC 23001-1 decoders152 13.5 DecoderInit.155 13.6 Decoding process156 Annex A (informative) Patent statements.160 Annex B (normative) Media
16、 Type Registrations 161 Bibliography167 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 00:28:30 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 14496-20:2008(E)
17、 ISO/IEC 2008 All rights reserved v 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 In
18、ternational 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 liai
19、son 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 tech
20、nical 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 14496
21、-20 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information. This second edition cancels and replaces the first edition (ISO/IEC 14496-20:2006) which has been technically revised. It also inc
22、orporates the Amendment ISO/IEC 14496-20:2006/Amd.1:2008 and the Technical Corrigenda ISO/IEC 14496-20:2006/Cor.1:2007 and ISO/IEC 14496-20:2006/Cor.2:2008. ISO/IEC 14496 consists of the following parts, under the general title Information technology Coding of audio-visual objects: Part 1: Systems P
23、art 2: Visual Part 3: Audio Part 4: Conformance testing Part 5: Reference software Part 6: Delivery Multimedia Integration Framework (DMIF) Part 7: Optimized reference software for coding of audio-visual objects Technical Report Part 8: Carriage of ISO/IEC 14496 contents over IP networks Part 9: Ref
24、erence hardware description Technical Report Part 10: Advanced Video Coding Part 11: Scene description and application engine Part 12: ISO base media file format Part 13: Intellectual Property Management and Protection (IPMP) extensions Part 14: MP4 file format Part 15: Advanced Video Coding (AVC) f
25、ile format Part 16: Animation Framework eXtension (AFX) Part 17: Streaming text format Part 18: Font compression and streaming Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 00:28:30 MSTNo repro
26、duction or networking permitted without license from IHS -,-,- ISO/IEC 14496-20:2008(E) vi ISO/IEC 2008 All rights reserved Part 19: Synthesized texture stream Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) Part 21: MPEG-J Graphics Framework eXtensi
27、ons (GFX) Part 22: Open Font Format Part 23: Symbolic Music Representation Part 24: Audio and systems interaction Technical Report Part 25: 3D Graphics Compression model Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not
28、for Resale, 01/31/2009 00:28:30 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 14496-20:2008(E) ISO/IEC 2008 All rights reserved vii Introduction ISO/IEC 14496-20 specifies syntax and semantics for the following: The Lightweight Application Scene Representation (LA
29、SeR), specified in Clause 6, which is a binary format for encoding 2D scenes and updates of scenes. The binary format and the scene representation (based on SVG Tiny) are both designed to be suitable for lightweight embedded devices such as mobile phones. A Simple Aggregation Format (SAF), specified
30、 in Clause 7, to efficiently and easily transport LASeR data together with audio and/or video content over various delivery channels. This multiplexing scheme is designed to be simple to implement and to allow efficient demultiplexing on low-end devices. The International Organization for Standardiz
31、ation (ISO) and International Electrotechnical Commission (IEC) draw attention to the fact that it is claimed that compliance with this document may involve the use of a patent. ISO and IEC take no position concerning the evidence, validity and scope of this patent right. The holder of this patent r
32、ight has assured ISO and IEC that he is willing to negotiate licences under reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this respect, the statement of the holder of this patent right is registered with ISO and IEC. Information may be obtained from
33、the companies listed in Annex A. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified in Annex A. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Copyright Internation
34、al Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 00:28:30 MSTNo reproduction or networking permitted without license from IHS -,-,- Copyright International Organization for Standardization Provided by IHS under licens
35、e with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 00:28:30 MSTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO/IEC 14496-20:2008(E) ISO/IEC 2008 All rights reserved 1 Information technology Coding of audio-visual objects Part 20: Lig
36、htweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) 1 Scope This part of ISO/IEC 14496 defines a scene description format (LASeR) and an aggregation format (SAF) respectively suitable for representing and delivering rich-media services to resource-constrained device
37、s such as mobile phones. LASeR aims at fulfilling all the requirements of rich-media services at the scene description level. LASeR supports an optimized set of objects inherited from SVG to describe rich-media scenes, a small set of key compatible extensions over SVG, the ability to encode and tran
38、smit a LASeR stream and then reconstruct SVG content, dynamic updating of the scene to achieve a reactive, smooth and continuous service, simple yet efficient compression to improve delivery and parsing times, as well as storage size, one of the design goals being to allow both for a direct implemen
39、tation of the SDL as documented, as well as for a decoder compliant with ISO/IEC 23001-1 to decode the LASeR bitstream, an efficient interface with audio and visual streams with frame-accurate synchronization, use of any font format, including the OpenType industry standard, and easy conversion from
40、 other popular rich-media formats in order to leverage existing content and developer communities. Technology selection criteria for LASeR included compression efficiency, but also code and memory footprint and performance. Other aims included: scalability, adaptability to the user context, extensib
41、ility of the format, ability to define small profiles, feasibility of a J2ME implementation, error resilience and safety of implementations. SAF aims at fulfilling all the requirements of rich-media services at the interface between media/scene description and existing transport protocols: simple ag
42、gregation of any type of stream, signalling of MPEG and non-MPEG streams, optimized packet headers for bandwidth-limited networks, easy mapping to popular streaming formats, Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001
43、Not for Resale, 01/31/2009 00:28:30 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 14496-20:2008(E) 2 ISO/IEC 2008 All rights reserved cache management capability, and extensibility. SAF has been designed to complement LASeR for simple, interactive services, bringi
44、ng efficient and dynamic packaging to cope with high latency networks, media interleaving, and synchronization support with a very low overhead. This part of ISO/IEC 14496 defines the usage of SAF for LASeR content; however, LASeR can be used independently from SAF. 2 Normative references The follow
45、ing referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 9899, Programming languages C ISO/IEC 13818-1, Info
46、rmation technology Generic coding of moving pictures and associated audio information: Systems ISO/IEC 14496-1, Information technology Coding of audio-visual objects Part 1: Systems ISO/IEC 14496-12, Information technology Coding of audio-visual objects Part 12: ISO base media file format ISO/IEC 14
47、496-18, Information technology Coding of audio-visual objects Part 18: Font compression and streaming ISO/IEC 14882:2003, Programming languages C+ ISO/IEC 16262:2002, Information technology ECMAScript language specification IETF BCP 13, RFC 4288 on Media Type Specifications and Registration Procedur
48、es, http:/www.ietf.org/rfc/rfc4288.txt IETF RFC 3023, XML Media Types, M. Murata, S. St. Laurent, D. Kohn, January 2001, http:/www.ietf.org/rfc/rfc3023.txt IETF RFC 3986, Uniform Resource Identifiers (URI): Generic Syntax, T. Berners-Lee, R. Fielding, L. Masinter, January 2005, http:/www.ietf.org/rfc/rfc3986.txt IETF R