Closed-captioning/ Text Superimposition Technology for 8K Broadcasting

摘要

The closed-captioning service of digital broadcasting separately transmits textual data describing a program's audio content, and the receiver superimposes it over the broadcast video. This service serves a wide audience, not only those with hearing difficulties, wherein text superimposition is also used to deliver urgent information such as emergency earthquake news flashes. 8K Super Hi-Vision (8K) broadcasting will also provide this important service. Here, NHK has proposed coding and transmission schemes for closed-captioning and text superimposition in 8K broadcasting that are compatible with MPEG Media Transport (MMT), and the Association of Radio Industries and Businesses (ARIB) has standardized them in Japan. The 8K satellite broadcasting experiment conducted during the STRL Open House in May 2015 displayed closed-captions (text superimposition) over 8K video on a standard-compliant transmission and reception system.