IEC 62731:2018 pdf download

IEC 62731:2018 pdf download.Text-to-speech for television – General requirements
1 Scope
This International Standard specifies the text-to-speech functionality 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 document applies only to completely 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 document refers to TV, this will be shorthand for all such receivers. This document 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
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
3.1 .9 subtitle textual representation of the dialogue (and frequently additional auditory information), typically shown at the bottom 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 “(closed) captioning”. Note 3 to entry: This document uses the term subtitles throughout. 3.1 .1 0 TTS audio audio generated by the TTS engine based on the TTS data Note 1 to entry: If the TV uses an external TTS converter, TTS audio is interpreted as TTS data. 3.1 .1 1 priority audio information audio information for immediate output typically related to emergency information 3.1 .1 2 TTS data (text) data converted into TTS audio information by the text-to-speech engine
4 Guiding principles and conventions
This document 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 visually impaired people experience when using and watching TV? Providing text-to-speech functionality for a broadcast receiver, for example a TV or an 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 separate device. In general as the guiding principle, when building a TTS interface in the context of this document, 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 information and be able to accomplish tasks similar to those they would with a graphical UI.A claim of conformity with this document requires conformity with all mandatory requirements. A TV-TTS device combination or a TV with a TTS that is integrated may provide options for a user to enable or disable each feature of a product. While options for user configurations may be provided, the product shall meet the mandatory requirements.
5 User requirements of visually impaired people
5.1 Users’ needs This subclause 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 user 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; e) navigating 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 document. Item c) further relates to the fact that, in some countries, foreign language programmes are 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 document elaborates on the remaining four items, i.e. d), e), f) and g), in 5.2 to 5.6.