This standard defines the required technology for closed caption and subtitle tracks over ROUTE-DASH and MMT transports. This includes the content essence and the packaging and timing.
Download current version: A/343:2022-03, “Captions and Subtitles”, published 31 March 2022. This version of the Standard is normatively referenced in A/300:2022-04.
There are multiple versions of this document. Please be sure to download the desired version. For amendments, the text includes a list of changes, the rationale for the changes, and compatibility considerations.
Download A/343:2018, “Captions and Subtitles”, approved 10 October 2018. This version is referenced by A/300:2019 and A/300:2020.
Download A/343:2018 Amendment No. 1, “Safe Area”, Approved 8 February 2021.
Download A/343:2018 Amendment No. 2, “Font Names”, Approved 20 September 2021.
Download A/343:2018, “Captions and Subtitles with Amendment No. 1”. This document has Amendment No. 1 integrated into the standard. This version is referenced by A/300:2021.
Download A/343:2018, “Captions and Subtitles with Amendments No. 1 and No. 2”. This document has Amendments No. 1 and No. 2 integrated into the standard.
Download A/343:2022-02, “Captions and Subtitles”, approved 10 February 2022.
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The Advanced Television Systems Committee, Inc., is an international, non-profit organization developing voluntary standards and recommended practices for digital terrestrial broadcasting. ATSC member organizations represent the broadcast, broadcast equipment, motion picture, consumer electronics, computer, cable, satellite, and semiconductor industries. ATSC also develops digital terrestrial broadcasting implementation strategies and supports educational activities on ATSC standards.