1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationText-to-speech for television General requirementsBS EN 62731:2013National forewordThis British Standard is the UK implementation of EN 62731:2013. It is identical to IEC 62731:2
2、013.The UK participation in its preparation was entrusted to Technical CommitteeEPL/100, Audio, video and multimedia systems and equipment.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary p
3、rovisions of acontract. Users are responsible for its correct application. The British Standards Institution 2013Published by BSI Standards Limited 2013ISBN 978 0 580 78588 7ICS 33.160.25; 33.160.99Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard
4、was published under the authority of the StandardsPolicy and Strategy Committee on 31 May 2013.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 62731:2013EUROPEAN STANDARD EN 62731 NORME EUROPENNE EUROPISCHE NORM April 2013 CENELEC European Committee for Electrotec
5、hnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 62
6、731:2013 E ICS 33.160.25; 33.160.99 English version Text-to-speech for television - General requirements (IEC 62731:2013) Synthse vocale pour tlvision - Exigences gnrales (CEI 62731:2013) Text-zu-Sprache fr Fernsehen - Allgemeine Anforderungen (IEC 62731:2013) This European Standard was approved by
7、CENELEC on 2013-03-05. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national sta
8、ndards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own langu
9、age and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, Franc
10、e, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 62731:2013EN 62731:2013 - 2 - Foreword The text of document 100/2070/FD
11、IS, future edition 1 of IEC 62731, prepared by IEC/TC 100 “Audio, video and multimedia systems and equipment“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 62731:2013. The following dates are fixed: latest date by which the document has to be implemented at national le
12、vel by publication of an identical national standard or by endorsement (dop) 2013-12-05 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2016-03-05 Attention is drawn to the possibility that some of the elements of this document may be the subject
13、of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 62731:2013 was approved by CENELEC as a European Standard without any modification. BS EN 62731:2013 2 62731 IEC:2013 CONTEN
14、TS 1 Scope . 5 2 Normative references . 5 3 Terms, definitions and abbreviations 5 3.1 Terms and definitions 5 3.2 Abbreviations 7 4 Guiding principles and conventions 7 5 User requirements of visually impaired people 7 5.1 Users needs . 7 5.2 Navigating channels 8 5.3 Navigating TV inputs . 8 5.4 A
15、dditional data services 8 5.5 Operating the TV . 8 5.6 TV use 9 6 Functional requirements . 9 6.1 Functionality for TV, TTS device combination 9 6.2 Functionality: TTS device/engine . 10 6.3 Functionality: TV . 10 6.4 Setting up: TV, TTS device combination 10 7 TV events and TTS data . 11 7.1 TV con
16、text and events . 11 7.2 TTS data per event 12 7.2.1 Details . 12 7.2.2 Channel change 12 7.2.3 Additional information 13 7.2.4 Navigation and selection 13 7.2.5 Context switch . 14 7.2.6 Pop-up message 15 8 TTS profiles 16 8.1 Basic profile 16 8.2 Main profile . 16 8.3 Enhanced profile . 17 8.4 Sum
17、mary . 17 Bibliography 19 Figure 1 TV TTS device system diagram . 9 Figure 2 Context event state diagram . 12 Table 1 Overview of profiles . 18 BS EN 62731:201362731 IEC:2013 5 TEXT-TO-SPEECH FOR TELEVISION GENERAL REQUIREMENTS 1 Scope This International Standard specifies the text-to-speech functio
18、nality for a (broadcast) receiver with a text-to-speech system. Such a system may be one device, i.e. a receiver with an integrated text-to-speech generator, or may be two devices, i.e. a receiver interfacing with an external text-to-speech device. This International Standard applies only to complet
19、ely functional stationary (or semi-stationary) digital TV receivers such as set top boxes, integrated digital TVs, recorders and other products whose primary function is to receive TV content. Where this standard refers to TV, this will be shorthand for all such receivers. This International Standar
20、d does not apply to products that are capable of receiving TV as a secondary function (e.g. PCs or game consoles with digital television receivers). It also does not apply to sub-assemblies (e.g. PC tuner cards). 2 Normative references The following documents, in whole or in part, are normatively re
21、ferenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. (void) 3 Terms, definitions and abbreviations 3.1 Terms and definitions
22、 For the purposes of this document, the following terms and definitions apply. 3.1.1 context one specific function of a TV EXAMPLE Watching TV, EPG, etc. 3.1.2 DTV broadcast event set of related broadcast streams with a defined start and end time, commonly referred to as a TV programme Note 1 to ent
23、ry: DTV events have typically the following properties associated with them: start time, end time or duration, content synopsis, additional content information, parental rating and availability of subtitles or audio description. 3.1.3 DTV service information metadata describing broadcasting content
24、and its scheduling and timing details Note 1 to entry: The purpose of DTV service information is to aid the end user to select and schedule viewing and recording, and also to select the equipment configuration. BS EN 62731:2013 6 62731 IEC:2013 3.1.4 DTV broadcast event classification general catego
25、ry of programme/event content, or its classification EXAMPLES Movie (drama), news/current affairs, talk show, sports (football), etc. 3.1.5 EPG filter filter that organises or reduces the list of displayed EPG items according to certain criteria EXAMPLES Of criteria are to show only: programmes with
26、 a certain content type; favourites; programmes that are audio described; programmes for a given time period (for instance “today“, “tomorrow“, “next 7 days“). 3.1.6 event trigger to start an action 3.1.7 list collection of items 3.1.8 menu subsequent order of items 3.1.9 receiver device capable of
27、receiving or handling digital television signals 3.1.10 service sequence of programs under the control of a broadcaster which can be broadcast as part of a schedule 3.1.11 subtitle textual representation of the dialogue (and frequently additional auditory information), typically shown at the bottom
28、of the screen Note 1 to entry: Subtitles can be a textual rendering in the same language as the spoken dialogue, or can provide a written translation in a different language. Note 2 to entry: In some parts of the world subtitles are called “(closed) captions“, and subtitling is referred to as “(clos
29、ed) captioning“. Note 3 to entry: This standard uses the term subtitles throughout. 3.1.12 TTS audio audio output by the TTS engine in correspondence with TTS data Note 1 to entry: If the TV uses an external TTS converter, TTS audio is interpreted as TTS data. 3.1.13 TTS data (text) data converted i
30、nto TTS audio information by the text-to-speech engine BS EN 62731:201362731 IEC:2013 7 3.2 Abbreviations For the purposes of this document, the following abbreviations apply. DTV digital television EPG electronic programme guide STB set top box TTS text-to-speech TV television UI user interface 4 G
31、uiding principles and conventions This standard describes the required basic behaviour for a TV text-to-speech combination in a basic profile, but also provides for enhanced profiles. It also gives a short introduction into the basic problems of visually impaired people: i.e. what are the problems v
32、isually impaired people experience when using and watching TV? Providing text-to-speech functionality for a broadcast receiver, e.g. TV or STB can be of great help to (visually) disabled people. Such speech functionality may be integrated in the receiver or may be external to the receiver in a separ
33、ate device. In general as the guiding principle, when building a TTS interface in the context of this standard, implementers should aspire to achieve functional equivalence of the user experience. This means that a person operating the device using the speech interface should have access to similar
34、information and be able to accomplish similar tasks as with a graphical UI. The main features of this International Standard are: basic functional description for a TV-TTS device combination or TV with integrated TTS; profiles for different levels of TV-TTS functionality; targeted towards the digita
35、l TV application. In this standard mandatory requirements are specified; optional and informative features are also included. A claim of conformity with this standard requires conformity with all mandatory requirements. A TV-TTS device combination or a TV with a TTS that is integrated may provide op
36、tions for a user to enable or disable product features. 5 User requirements of visually impaired people 5.1 Users needs This subclause 5.1 explains the needs of visually impaired people as the primary target users for a TV with TTS. Unless these needs are met, the system is not accessible to this us
37、er group. Visually impaired people experience access barriers in the course of the following activities when watching TV: a) following TV programming, e.g. the TV series; b) using a remote control; c) not being able to see subtitles; d) navigating channels; BS EN 62731:2013 8 62731 IEC:2013 e) navig
38、ating TV inputs; f) using additional data (text) services provided by the broadcaster, e.g. an EPG; g) daily operation of the TV and initial setup of the TV for use. Items a), b) and c) are outside the scope of this standard. Item c) further relates to the fact that in some countries foreign languag
39、e programmes are being translated via subtitles. For users who cannot see the subtitles, supplementary audio services are sometimes used to deliver an audio version of the subtitles. This standard elaborates on the remaining four items, i.e. d), e), f) and g), in 5.2 to 5.6. NOTE 1 For DVB systems,
40、item a) is already solved by audio description. Also, the use case of providing supplementary audio services to deliver an audio version of the subtitles is covered in the DVB-SI specification ETSI EN 300 468. NOTE 2 For ATSC systems, the audio system includes a visually impaired (VI) associate serv
41、ice which allows a complete programme mix containing music, effects, dialogue, and additionally a narrative description of the picture content, see ATSC A/53 part 5 and part 6. 5.2 Navigating channels The problem is a user does not know which channel the TV displays, i.e. the user gets “lost during
42、navigation”. The TV is displaying navigation data on the screen but the user is unable to see it. Such data are for example: channel number, service name, (DTV broadcast) event name. 5.3 Navigating TV inputs The problem is that a user is unable to select the required input to the TV, e.g. the user w
43、ishes to select DTV or a specific external input linked to a recording or other device. The choice is shown on the screen but the user is unable to see it. 5.4 Additional data services With digital TV a broadcaster may transmit additional data (text) services to augment TV programming, provide addit
44、ional information on programming, or provide news. Such additional data are: information about whether audio description, subtitling is available, (next) (DTV broadcast) event name, (DVB-) event information (enhanced description of the (DTV broadcast) event), EPG data. The items above are listed in
45、order of importance with the most important item appearing first. It is noted that this data provides additional convenience in using the TV, but that is non-essential for the primary function of watching TV, and selecting channels. 5.5 Operating the TV User settings are another needed function besi
46、des navigation. This can be done through buttons on the remote control (out of scope for this specification), but also via on-screen menus. For visually impaired people on-screen menus are typically of little use. A distinction exists between initial setup and daily operation of the TV. Initial setu
47、p is typically a onetime operation during the lifetime of a TV. Daily operation is more frequent and more important. Consequently a distinction among menu items for daily operation exists, those addressing specific accessibility functions, and TV setup menu items. However, the most frequently used k
48、eys are “volume”, “channel up/down”, and number keys. BS EN 62731:201362731 IEC:2013 9 5.6 TV use Use characterization of a TV helps in determining implementation profiles. Navigating channels, for example, is done most often when watching TV, as well as commands like volume up and down. This may be
49、 supported by additional data services, but does not affect the primary functions of the TV. Changing the TVs system settings is not done very often, except perhaps for changing sound or video settings or switching audio description on and off. Such settings may have an easy access mode through a special menu. TV installation is typically performed only once during the lifetime of the TV. Often, visually impaired people can benefit from specialized support for installing the TV,
