ITU-T T.701.25 PDF

This Recommendation provides recommendations on the audio presentation of captions/subtitles and other on-screen text for use in all types of videos regardless of the language and technology being used to transmit and present the recorded or live video.

This Recommendation 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 nonnative 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.

This Recommendation 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 [b-ITU-T T.701.21].

This Recommendation 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, digital versatile disk (DVD) and home cinema equipment, cinema equipment and other forms of user interface technology. Therefore, this Recommendation does not consider transcoding files for the various video and audio outputs.

NOTE 2 – Technical matters of transmission and distribution are covered by other international standards (e.g., MPEG standards and other technical international standards such as [b-IEC 62731]).

This Recommendation 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.