BS PD ISO/IEC TS 20071-21:2015提供了在听觉系统中描述视听内容的建议 用于录制视频演示、广播电视、电影、现场或录制戏剧的模式， 博物馆和美术馆的展品、遗产旅游、新闻和喜剧，无论语言和文化 用于传输和呈现录制或直播的视听内容的技术。注1:音频描述有许多次用户，但音频描述的主要用户和预期用户 描述为盲人或低视力者及其朋友和家人。ISO/IEC 20071的这一部分提供了有关创建音频描述的主观性质的指南。它还为音频描述开发人员（脚本编写者、语音叙述者和 负责提供音频描述（音频描述）的组织或团体 代表视听内容。注2:由于数量限制，可能并不总能提供同等的体验 音频描述的可用时间取决于所描述的内容。ISO/IEC 20071的这一部分适用于描述视听内容而不考虑设备。 或用于传递内容或音频描述的传输机制。这些设备包括:， 但不限于电视、电脑、无线设备、投影设备、DVD和家用设备 影院设备和其他形式的用户界面技术。因此，ISO/IEC 20071的这一部分 不考虑代码转换文件用于各种视频输出。注3:输电和配电的技术问题由其他国际标准涵盖（例如:。 MPEG标准和其他国际技术标准，如IEC 62731）。 ISO/IEC 20071的这一部分提供了如何接近用户偏好、可用样式的指南 以及音频描述方法的灵活性。它不适用于包含在电子文档中的静态图像（指南见ISO/IEC 20071-11） 关于图像的文本替换）。它适用于同时传送或传递给用户的听觉演示 原创视听内容。注4:广播公司或同步环境中的人员所经历的限制可能会减少 在线或异步环境。交叉引用:ISO/IEC 20071-11IEC 62731购买时可用的所有现行修订版均包含在本文件的购买中。

BS PD ISO/IEC TS 20071-21:2015 provides recommendations for describing audiovisual content in an auditory modality for use in recorded video presentations, broadcast television, cinema, live or recorded drama, museum and art gallery exhibits, heritage tours, news, and comedies, regardless of the language and technology being used to transmit and present the recorded or live audiovisual content.NOTE 1 There are many secondary users of audio description, but the primary and intended users of audio description are blind persons or persons with low vision and their friends and family.This part of ISO/IEC 20071 provides guidance on the subjective nature of creating audio description.It also provides guidance for audio description developers (script writers, voice narrators, and organizations or groups responsible for delivering audio description) in faithfully and accurately representing audiovisual content.NOTE 2 It might not always be possible to provide an equivalent experience due to limitations in the amount of time available for audio description depending on the content being described.This part of ISO/IEC 20071 applies to describing audiovisual content and does not consider the devices or transmission mechanisms used to deliver the content or the audio description. These devices include, but are not limited to, televisions, computers, wireless devices, projection equipment, DVD and home cinema equipment and other forms of user interface technology. Therefore, this part of ISO/IEC 20071 does not consider transcoding files for the various video outputs.NOTE 3 Technical matters of transmission and distribution are covered by other International Standards (e.g. MPEG standards and other technical international standards such as IEC 62731).This part of ISO/IEC 20071 provides guidance on how to approach user preferences, available styles and flexibility in approaches to audio description.It does not apply to static images contained in electronic documents (see ISO/IEC 20071-11 for guidance on text alternatives for images).It applies to auditory presentations intended to be transmitted or delivered simultaneously to the original audiovisual content.NOTE 4 Limitations experienced by broadcasters or people in synchronous environments might be reduced online or in asynchronous environments.Cross References:ISO/IEC 20071-11IEC 62731All current amendments available at time of purchase are included with the purchase of this document.