信息技术.用户界面组件的可访问性.第25部分：视频中文本的音频表示指南，包括字幕、字幕和其他屏幕文本

[中文适用范围]： 本文件提供了关于视频中标字/字幕和其他屏幕文本的语音呈现的建议，适用于所有类型的视频，无论使用的语言和技术如何。这些标准针对需要辅助功能的用户，包括但不限于有学习或阅读障碍、认知障碍、盲人或视力低下、老年人以及非母语使用者。不适用于内容已经在音频轨道中以用户可访问的语言和方式提供的标字/字幕或其他屏幕文本。 [外文原描述]： ISO/IEC TS 20071-25:2017 provides recommendations on the audio presentation of captions/subtitles and other on-screen text for use in all type of videos regardless of the language and technology being used to transmit and present the recorded or live video. ISO/IEC TS 20071-25:2017 applies to making captions/subtitles and other on-screen text accessible to users with various needs, including but not limited to people with learning and reading disabilities, people with cognitive disabilities, people who are blind or have low vision, older people, and non-native language speakers. It does not apply to captions/subtitles or other on-screen text whose content is already provided in the soundtrack in a language and a way users can access. ISO/IEC TS 20071-25:2017 provides guidance on spoken captions/subtitles as a stand-alone access service but it also provides guidance on how to integrate spoken captions/subtitles, other spoken on-screen text and audio description, if needed, in different types of videos. NOTE 1 Extensive guidance on audio description is provided in ISO/IEC/TS 20071‑21. ISO/IEC TS 20071-25:2017 does not consider the devices or transmission mechanisms used to deliver and play the content or the audio presentation of text in videos. These devices include, but are not limited to televisions, computers, wireless devices, projection equipment, DVD and home cinema equipment, cinema equipment and other forms of user interfaces technology. Therefore, this document does not consider transcoding files for the various video and audio outputs. NOTE 2 Technical matters of transmission and distribution are covered by other documents (e.g. MPEG standards and other technical standards such as IEC 62731:2013). ISO/IEC TS 20071-25:2017 acknowledges the various needs and preferences of users, as well as the different approaches to the audio presentation of text in videos. It applies to audio presentations intended to be heard simultaneously along with the original video.