Implementation of Closed Captioning System for Terrestrial UHD Based on ATSC 3.0
In South South Korea, terrestrial ultrahigh-definition (UHD) broadcasting using the ATSC 3.0 standard officially began at the end of May 2017. To provide closed captions for the UHD programs, we developed an ATSC 3.0 closed captioning system. The ATSC 3.0 closed caption standard is based on Internet Media Subtitles and Captions 1.0 (IMSC1), which is mainly used in online video streaming. Captions in the previous ATSC 1.0 standard were based on Consumer Electronics Association 708. The UHD programs broadcast on Korean UHD TV networks are simulcast on South Korea’s ATSC1 HD networks. Since the HD and UHD programs are the same except for their video quality, the UHD programs reuse captions from the HD programs, which are produced using live stenography. We implemented the ATSC3 closed captioning system, both for MPEG media transport and realtime object delivery over unidirectional transport, which are transport protocols in the ATSC 3.0 standard, and verified it by testing on commercial ATSC 3.0 UHD TV receivers. This is the world’s first development of the IMSC1 closed captioning system on terrestrial TV.
- Print ISSN
- 1545-0279
- Electronic ISSN
- 2160-2492
- Published
- 2018-05
- Content type
- Original Research
- Keywords
- IMSC1, TTML, UHD closed caption, UHD closed captioning system
- DOI
- 10.5594/JMI.2018.2806518