1、Information technology Coding of audio-visual objects Part 4: Conformance testing AMENDMENT 26: Conformance levels and bitstreams for Open Font FormatAmendment 26:2009 (IDT) toNational Standard of CanadaCAN/CSA-ISO/IEC 14496-4-06(ISO/IEC 14496-4:2004, IDT)NOT FOR RESALE.PUBLICATION NON DESTINE LA RE
2、VENTE.CSA Standards Update ServiceAmendment 26:2009 toCAN/CSA-ISO/IEC 14496-4-06October 2009Title: Information technology Coding of audio-visual objects Part 4: Conformance testing AMENDMENT 26: Conformance levels and bitstreams for Open Font FormatPagination: 7 pages (iii preliminary and 4 text)To
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4、upportcsa.ca or call 416-747-2233.Visit CSAs policy on privacy at www.csagroup.org/legal to find out how we protect your personal information.Reference numberISO/IEC 14496-4:2004/Amd.26:2008(E)ISO/IEC 2008INTERNATIONAL STANDARD ISO/IEC14496-4Second edition2004-12-15AMENDMENT 262008-10-01Information
5、technology Coding of audio-visual objects Part 4: Conformance testing AMENDMENT 26: Conformance levels and bitstreams for Open Font Format Technologies de linformation Codage des objets audiovisuels Partie 4: Essai de conformit AMENDEMENT 26: Niveaux de conformit et bitstreams pour format de police
6、ouvert ISO/IEC 14496-4:2004/Amd.26:2008(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 licensed to and installed on the computer perform
7、ing 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 the software products used to create this PDF
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9、retariat 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 photocopying and microfilm, without permission in
10、 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 ii ISO/IEC 2008 All rights reservedAmendment 26:2009 toCAN/CS
11、A-ISO/IEC 14496-4-06ISO/IEC 14496-4:2004/Amd.26:2008(E) ISO/IEC 2008 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried
12、out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO
13、collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare Internationa
14、l Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the eleme
15、nts of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Amendment 26 to ISO/IEC 14496-4:2004 was prepared by Technical Committee ISO/IEC/TC , Information Technology, Subcommittee SC 29, Coding of audio, picture, multi
16、media and hypermedia information. It defines the conformance test procedures for implementations compliant with ISO/IEC 14496-22 “Open Font Format” and ISO/IEC 14496-18 “Font compression and streaming”. Amendment 26:2009 toCAN/CSA-ISO/IEC 14496-4-06ISO/IEC 14496-4:2004/Amd.26:2008(E) ISO/IEC 2008 Al
17、l rights reserved 1Information technology Coding of audio-visual objects Part 4: Conformance testing AMENDMENT 26: Conformance levels and bitstreams for Open Font Format After 4.15, add the following subclause: 4.16 Font data conformance 4.16.1 Font data conformance levels 4.16.1.1 Open Font conform
18、ance levels ISO/IEC 14496-22 “Open Font Format” (OFF) defines an extensible mechanism for font data representation that is based on the industry standard OpenType1)font format. The standard allows representation of font data with outline information encoded in one of the two basic formats with TrueT
19、ype2)outlines, and with outlines encoded using Compact Font Format (CFF, a compressed representation of Adobe PostScript3)Type 1 fonts) developed by Adobe Systems Incorporated. Font data may be represented using collections of tables, which include a set of required tables, a set of tables that are
20、related to TrueType outlines, a set of tables that are related to CFF outlines, and a set of relevant optional tables, e.g. the tables that support advanced typographic features and advanced text layout for complex scripts. The five different OFF conformance levels are defined, which correspond to t
21、he following functionality of fonts: 1) Fonts that contain only required tables and the subset of tables related to TrueType outlines with no hints (i.e. unhinted TrueType outlines only). Conformance at this level shall be claimed if the following set of tables is supported: cmap, head, hhea, hmtx,
22、maxp, name, OS/2, post, loca and glyf (where hint instructions that may be part of glyph outline data should be ignored). 2) Fonts that contain only required tables and the full set of tables related to TrueType outlines (including TrueType hints). Conformance at this level shall be claimed only if
23、the following set of tables is supported: cmap, head, hhea, hmtx, maxp, name, OS/2, post, cvt, fpgm prep, loca and glyf. 3) Fonts that contain only required tables and the tables related to CFF outlines. Conformance at this level shall be claimed if the following set of tables is supported: cmap, he
24、ad, hhea, hmtx, maxp, name, OS/2, post, CFF and VORG. Please note that this level may include OFF TTC fonts with CFF outlines, however, support for TTC font collections is not required for terminals claiming compliance at this level. 1) OpenType is a registered trademark of Microsoft Corporation. 2)
25、 TrueType is a trademark of Apple Inc. 3) PostScript is a registered trademark of Adobe Systems Incorporated. Amendment 26:2009 toCAN/CSA-ISO/IEC 14496-4-06ISO/IEC 14496-4:2004/Amd.26:2008(E) 2 ISO/IEC 2008 All rights reserved4) Fonts supporting embedded bitmaps. Conformance at this level shall be c
26、laimed if a font supports any of the previously identified subsets of tables (Levels 1 3), plus the tables related to bitmap glyphs EBDT, EBLC and EBSC. 5) Fonts supporting complex languages scripts. Conformance at this level shall be claimed if a font supports any of the previously identified subse
27、ts of tables (Levels 1 3), plus additional optional advanced typographic tables: BASE, GDEF, GPOS, GSUB and JSTF. 4.16.1.2 Font compression and streaming conformance levels Clause 6 of ISO/IEC 14496-18 defines MPEG-4 Text profiles and levels. Simple and Advanced Simple text profiles limit font capab
28、ilities to using fonts with TrueType outlines only, while Main text profile provides for full-featured font data supporting either TrueType or CFF outlines. MPEG terminals that claim compliance with Simple text profile SHALL be able to render OFF font data conformant to Level 1 defined in 4.16.1.1.
29、MPEG terminals claim compliance with Advanced Simple text profile SHALL be able to render OFF font data conformant to Levels 1, 2, 4 and 5. MPEG terminals that claim compliance to Main text profile SHALL be able to render OFF font data conformant with all five OFF conformance levels. In addition to
30、three different text profiles, ISO/IEC 14496-18 also defines different levels of text profile. In each Text Profile, Level 1 supports rendering of resident fonts only presented in OFF, while Level 2 and Level 3 provide additional support for streaming of uncompressed and compressed font data, corres
31、pondingly, in the format defined in Clause 5 of ISO/IEC 14496-18. 4.16.2 Bitstream conformance 4.16.2.1 Conformance requirements Each font data bitstream shall comply with the syntactic and semantic requirements specified in ISO/IEC 14496-22 and ISO/IEC 14496-18 (where applicable). 4.16.2.2 Toleranc
32、e There is no tolerance for bitstream syntax checking. The diagnosis is pass or fail. 4.16.3 Terminal conformance 4.16.3.1 Conformance requirements This subclause defines procedures to verify conformance of terminals. Each decoder that claims compliance to one of the conformance levels specified in
33、4.16.1 shall be able to decode all required and optional tables that are relevant to that conformance level. 4.16.3.2 Conformance test procedure Tests are performed using error free input test sequences (bitstreams). Terminals shall test and verify the presence of necessary font tables and the valid
34、ity of data within those tables. Should a test bitstream contain any additional (optional) tables that are not covered by the specific conformance level, the table should be ignored for the purpose of terminal conformance testing. 4.16.4 Test sequences Tables AMD26.1 and AMD 26.2 describe the test s
35、equences to be used for terminal conformance testing. Amendment 26:2009 toCAN/CSA-ISO/IEC 14496-4-06ISO/IEC 14496-4:2004/Amd.26:2008(E) ISO/IEC 2008 All rights reserved 3Table AMD26.1 OFF Test Suite Information Bitstream name Number of glyphs Character set Supported tables Conformance levels courier
36、_min.ttf 94 Latin 1 (partial subset) OS/2 cmap glyf head hhea hmtx loca maxp name post This bitstream shallbe used for terminal conformance tests of Open Font solutions at OFF level 1: Unhinted TrueType outlines only. courier_complex.ttf 1127 Latin 1 Latin 1 supplement Latin Ext. A Greek Cyrillic He
37、brew Arabic Arabic Presentation Forms A Arabic Presentation Forms B (partial subsets) EBDT EBLC GDEF GSUB OS/2 VDMX cmap cvt fpgm gasp glyf head hhea hmtx loca maxp name post prep This bitstream shall be used for terminal conformance tests of Open Font solutions at OFF levels 2, 4 and 5: Hinted True
38、Type outlines and advanced typographic features (tables related to advanced typographic features shall be ignored when testing OFF level 2 and OFF level 4 compliance). Amendment 26:2009 toCAN/CSA-ISO/IEC 14496-4-06ISO/IEC 14496-4:2004/Amd.26:2008(E) 4 ISO/IEC 2008 All rights reservedcourier_cff.otf
39、94 Latin 1 (partial subset) CFF OS/2 cmap head hhea hmtx maxp name post This bitstream shall be used for terminal conformance tests of Open Font solutions at OFF level 3: CFF outlines only. Table AMD26.2 Test Suite Information for MPEG-4 Text profiles Bitstream name Name of the font file encoded wit
40、hin the bitstream Content description and relevant conformance levels courier_min_ttf.mp4 courier_min.ttf This bitstream contains uncompressed font with TrueType outlines and shall be used for conformance testing of MPEG terminals claiming compliance to Simple, Advanced Simple and Main text profiles
41、 at Levels 2 and 3. courier_min_cmp.mp4 courier_min.ttf This bitstream contains compressed font with TrueType outlines (only glyf table has been compressed) and shall be used for conformance testing of MPEG terminals claiming compliance to Simple, Advanced Simple and Main text profiles at Level 3. c
42、ourier_complex_ttf.mp4 courier_complex.ttf This bitstream contains uncompressed font with TrueType outlines and shall be used for conformance testing of MPEG terminals claiming compliance to Advanced Simple and Main text profile at Levels 2 and 3. courier_complex_cmp.mp4 courier_complex.ttf This bit
43、stream contains compressed font with TrueType outlines (only glyf table has been compressed) and shall be used for conformance testing of MPEG terminals claiming compliance to Advanced Simple and Main text profile at Level 3. courier_cff.mp4 courier_cff.otf This bitstream contains uncompressed font
44、with CFF outlines and shall be used for conformance testing of MPEG terminals claiming compliance to Main text profile at Levels 2 and 3. NOTE The conformance testing of MPEG terminals claiming compliance to Level 1 of corresponding Text profiles should be done using the original font files defined
45、in Table AMD26.1. Amendment 26:2009 toCAN/CSA-ISO/IEC 14496-4-06ISO/IEC 14496-4:2004/Amd.26:2008(E) ICS 35.040 ISO/IEC 2008 All rights reserved Copyright NoticeThis Amendment to the International Standard contains information copyright protected by the International Organization for Standardization
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