1、 ETSI TS 126 245 V15.0.0 (2018-07) Universal Mobile Telecommunications System (UMTS); LTE; Transparent end-to-end Packet switched Streaming Service (PSS); Timed text format (3GPP TS 26.245 version 15.0.0 Release 15) TECHNICAL SPECIFICATION ETSI ETSI TS 126 245 V15.0.0 (2018-07)13GPP TS 26.245 versio
2、n 15.0.0 Release 15Reference RTS/TSGS-0426245vf00 Keywords LTE,UMTS ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803
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8、Members. 3GPPTM and LTETMare trademarks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. oneM2M logo is protected for the benefit of its Members. GSMand the GSM logo are trademarks registered and owned by the GSM Association. ETSI ETSI TS 126 245 V15.0.0 (20
9、18-07)23GPP TS 26.245 version 15.0.0 Release 15Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-m
10、embers, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (https:/ipr.etsi.org/). Pursu
11、ant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present docu
12、ment. Trademarks The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners. ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no right to use or reproduce any trademark and/or trade
13、name. Mention of those trademarks in the present document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP). The present do
14、cument may refer to technical specifications or reports using their 3GPP identities, UMTS identities or GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables. The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under http:/web
15、app.etsi.org/key/queryform.asp. Modal verbs terminology In the present document “shall“, “shall not“, “should“, “should not“, “may“, “need not“, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of prov
16、isions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. ETSI ETSI TS 126 245 V15.0.0 (2018-07)33GPP TS 26.245 version 15.0.0 Release 15Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 4g3Introduction 4g31 Sc
17、ope 5g32 References 5g33 Definitions and abbreviations . 5g33.1 Definitions 5g33.2 Abbreviations . 6g34 Overview 6g35 Timed text format . 6g35.1 Unicode Support . 6g35.2 Bytes, Characters, and Glyphs 6g35.3 Character Set Support . 6g35.4 Font Support . 7g35.5 Fonts and Metrics . 7g35.6 Colour Suppor
18、t . 7g35.7 Text rendering position and composition . 8g35.8 Marquee Scrolling 9g35.9 Language 10g35.10 Writing direction 10g35.11 Text wrap 11g35.12 Highlighting, Closed Caption, and Karaoke . 11g35.13 Media Handler 11g35.14 Media Handler Header . 11g35.15 Style record 11g35.16 Sample Description Fo
19、rmat 12g35.17 Sample Format . 13g35.17.1 Sample Modifier Boxes 13g35.17.1.1 Text Style 13g35.17.1.2 Highlight . 14g35.17.1.3 Dynamic Highlight 14g35.17.1.4 Scroll Delay. 15g35.17.1.5 HyperText . 15g35.17.1.6 Textbox . 15g35.17.1.7 Blink 16g35.17.1.8 Text Wrap Indication 16g35.17.1.9 Stereo Disparity
20、 . 16g35.18 Combinations of features 16g3Annex A (informative): Change history . 18g3History 19g3ETSI ETSI TS 126 245 V15.0.0 (2018-07)43GPP TS 26.245 version 15.0.0 Release 15Foreword This Technical Specification has been produced by the 3rdGeneration Partnership Project (3GPP). The contents of the
21、 present document are subject to continuing work within the TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an identifying change of release date and an increase in version number as follows: Version
22、 x.y.z where: x the first digit: 1 presented to TSG for information; 2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. z the third
23、 digit is incremented when editorial only changes have been incorporated in the document. The 3GPP transparent end-to-end packet-switched streaming service (PSS) specification consists of six 3GPP TSs: 3GPP TS 22.233 1, 3GPP TS 26.233 2, 3GPP TS 26.234 3, 3GPP TS 26.244 4, 3GPP TS 26.246 5 and the p
24、resent document. The TS 22.233 contains the service requirements for the PSS. The TS 26.233 provides an overview of the PSS. The TS 26.234 provides the details of protocol and codecs used by the PSS. The TS 26.244 defines the 3GPP file format (3GP) used by the PPS and MMS services. The TS 26.246 def
25、ines the 3GPP SMIL language profile. The present document defines the Timed text format used by the PSS. The TS 26.244, TS 26.245 (present document) and TS 26.246 start with Release 6. Earlier releases of the 3GPP file format, the Timed text format and the 3GPP SMIL language profile can be found in
26、TS 26.234. Introduction Timed text is text that is rendered at the terminal, in synchronization with other timed media such as video or audio. Timed text is used for such applications as closed captioning, titling, and other visual annotation of timed media. ETSI ETSI TS 126 245 V15.0.0 (2018-07)53G
27、PP TS 26.245 version 15.0.0 Release 151 Scope The present document defines the timed text format relative to the 3GPP file format. This specification defines the format of timed text in downloaded files. 2 References The following documents contain provisions which, through reference in this text, c
28、onstitute provisions of the present document. - References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific. - For a specific reference, subsequent revisions do not apply. - For a non-specific reference, the latest version applies. In the
29、case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document. 1 3GPP TS 22.233: “Transparent End-to-End Packet-switched Streaming Service; Service aspects; Stage 1“. 2
30、3GPP TS 26.233: “Transparent end-to-end packet switched streaming service (PSS); General description“. 3 3GPP TS 26.234: “Transparent end-to-end packet switched streaming service (PSS); Protocols and codecs“. 4 3GPP TS 26.244: “Transparent end-to-end packet switched streaming service (PSS); 3GPP fil
31、e format (3GP)“. 5 3GPP TS 26.246: “Transparent end-to-end packet switched streaming service (PSS); 3GPP SMIL Language Profile“. 6 3GPP TR 21.905: “Vocabulary for 3GPP Specifications“. 7 The Unicode Consortium: “The Unicode Standard“, Version 3.0 Reading, MA, Addison-Wesley Developers Press, 2000, I
32、SBN 0-201-61633-5. 8 “Unicode Standard Annex #13: Unicode Newline Guidelines“, by Mark Davis. An integral part of The Unicode Standard, Version 3.1. 9 ISO/IEC 14496-14:2003 “Information technology Coding of audio-visual objects Part 14: MP4 file format“. 10 ETSI EN 300 743 v1.4.1“Digital Video Broad
33、casting (DVB); Subtitling systems“. 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: continuous media: media with an inherent notion of time. In the present document speech, audio, video and timed text discrete media
34、: media that itself does not contain an element of time. In the present document all media not defined as continuous media PSS client: client for the 3GPP packet switched streaming service based on the IETF RTSP/SDP and/or HTTP standards, with possible additional 3GPP requirements according to the p
35、resent document ETSI ETSI TS 126 245 V15.0.0 (2018-07)63GPP TS 26.245 version 15.0.0 Release 15PSS server: server for the 3GPP packet switched streaming service based on the IETF RTSP/SDP and/or HTTP standards, with possible additional 3GPP requirements according to the present document 3.2 Abbrevia
36、tions For the purposes of the present document, the abbreviations given in 3GPP TR 21.905 6 and the following apply. 3GP 3GPP file format MMS Multimedia Messaging Service MP4 MPEG-4 file format PSS Packet-switched Streaming Service SMIL Synchronised Multimedia Integration Language UTF-8 Unicode Tran
37、sformation Format (the 8-bit form) UTF-16 Unicode Transformation Format (the 16-bit form) 4 Overview Operators may specify additional rules and restrictions when deploying terminals, in addition to this specification, and behavior that is optional here may be mandatory for particular deployments. In
38、 particular, the required character set is almost certainly dependent on the geography of the deployment. 5 Timed text format 5.1 Unicode Support Text in this specification uses the Unicode 3.0 7 standard. Terminals shall correctly decode both UTF-8 and UTF-16 into the required characters. If a term
39、inal receives a Unicode code, which it cannot display, it shall display a predictable result. It shall not treat multi-byte UTF-8 characters as a series of ASCII characters, for example. Authors should create fully-composed Unicode; terminals are not required to handle decomposed sequences for which
40、 there is a fully-composed equivalent. Terminals shall conform to the conformance statement in Unicode 3.0 section 3.1. Text strings for display and font names are uniformly coded in UTF-8, or start with a UTF-16 BYTE ORDER MARK (uFEFF) and by that indicate that the string which starts with the byte
41、 order mark is in UTF-16. Terminals shall recognise the byte-order mark in this byte order; they are not required to recognise byte-reversed UTF-16, indicated by a byte-reversed byte-order mark. 5.2 Bytes, Characters, and Glyphs This clause uses these terms carefully. Since multi-byte characters are
42、 permitted (i.e. 16-bit Unicode characters), the number of characters in a string may not be the number of bytes. Also, a byte-order-mark is not a character at all, though it occupies two bytes. So, for example, storage lengths are specified as byte-counts, whereas highlighting is specified using ch
43、aracter offsets. It should also be noted that in some writing systems the number of glyphs rendered might be different again. For example, in English, the characters fi are sometimes rendered as a single ligature glyph. In this specification, the first character is at offset 0 in the string. In reco
44、rds specifying both a start and end offset, the end offset shall be greater than or equal to the start offset. In cases where several offset specifications occur in sequence, the start offset of an element shall be greater than or equal to the end offset of the preceding element. 5.3 Character Set S
45、upport All terminals shall be able to render Unicode characters in these ranges: a) basic ASCII and Latin-1 (u0000 to u00FF), though not all the control characters in this range are needed; ETSI ETSI TS 126 245 V15.0.0 (2018-07)73GPP TS 26.245 version 15.0.0 Release 15b) the Euro currency symbol (u2
46、0AC) c) telephone and ballot symbols (u260E through u2612) Support for the following characters is recommended but not required: a) miscellaneous technical symbols (u2300 through u2335) b) Zapf Dingbats: locations u2700 through u27AF, and the locations where some symbols have been relocated (e.g. u2
47、605, Black star). The private use characters u0091 and u0092, and the initial range of the private use area uE000 through uE0FF are reserved in this specification. For these Unicode values, and for control characters for which there is no defined graphical behaviour, the terminal shall not display a
48、ny result: neither a glyph is shown nor is the current rendering position changed. 5.4 Font Support Fonts are specified in this specification by name, size, and style. There are three special names which shall be recognized by the terminal: Serif, Sans-Serif, and Monospace. It is strongly recommende
49、d that these be different fonts for the required characters from ASCII and Latin-1. For many other characters, the terminal may have a limited set or only a single font. Terminals requested to render a character where the selected font does not support that character should substitute a suitable font. This ensures that languages with only one font (e.g. Asian languages) or symbols for which there is only one form are rendered. Fonts are requested by name, in an ordered list. Authors should normally specify one of the s
