GB/T 44882-2024Information technology - Closed captioning (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part

1.Structure and drafting rules for standardization documents" Drafting. Please note that some of the contents of this document may involve patents. The issuing organization of this document does not assume the responsibility for identifying patents. This document was proposed and coordinated by the National Information Technology Standardization Technical Committee (SAC/TC28). This document was drafted by: Beijing University of Technology, Shanghai University of Engineering Science, Shanghai Guomao Digital Technology Co., Ltd., Paco Video Technology (Hangzhou) Co., Ltd., Peking University, Shanghai Jiao Tong University, China Mobile (Hangzhou) Information Technology Co., Ltd., Beijing Subway Operation Co., Ltd. Zhejiang University, Tsinghua University, Qinghai University, Tencent Technology (Shenzhen) Co., Ltd., China International Television Corporation, CCTV International Network Co., Ltd. Company, Internet Society of China, China Electronics Technology Standardization Institute, iFLYTEK Co., Ltd., Anhui Tingjian Technology Co., Ltd., Beijing Boya Ruishi Technology Co., Ltd., Migu Culture Technology Co., Ltd., ZTE Corporation, and Yuyitong (Beijing) Intelligent Media Technology Development Co., Ltd., Beijing Mudan Electronics Group Co., Ltd., Beijing National Engineering Laboratory for Digital Television Co., Ltd., Hebei Broadcasting Wireless Media Co., Ltd., Guangdong Bohua Ultra High Definition Innovation Center Co., Ltd., Shandong Baimeng Information Technology Co., Ltd., Zhongguancun Video Listen to the Industrial Technology Innovation Alliance and Pengcheng Laboratory. The main drafters of this document are. Mou Luntian, Zhao Haiwu, Fu Qiang, Ma Siwei, Xu Yiling, Ma Nan, Hu Yongli, Luo Hong, Wei Yun, Zhang Kejun, Bu Jiajun, Zhang Yong, Shao Lei, Shi Yuanchun, Hu Ying, Luo Wei, Sheng Yao, Huang Chang, Li Jingxin, Liu Cong, Wang Wei, Cheng Ming, Xu Xiaozhong, Wang Tanshe, Li Lin, Xu Song, Shan Huaqi, Huang Cheng, Yu Jian, Mao Ke, Wang Wei, Yu Zhi, Zhou Sheng, Yang Yanjun, Wang Yu, Fan Tao, Hou Puyue, Jiang Zhiqian, Bai Yaxian, Li Qiuting, Liu Jianlong, Song Guodong, Bian Xiangguo, Jiang Yunxiong, Qiu Puye, Qu Wenyong, Yuan Yuan, Sui Kangni, Li Siyuan, Liu Yuhua, Jiao Lei, Lu Jinyu, Long Shiqiang, Xiao Tiejun, Chen Zhimin, Zhao Hongwei, Fu Qiang, Zhai Guangyao, Wei Jia, Han Wei, Jiang Donglai, Zhao Haiying, Yin Baocai, Wang Guozhong, Zhang Weimin, Huang Tiejun, Gao Wen. Information Technology Closed Captioning

1 Scope

GB/T 44882-2024 is the Chinese standard for closed captioning, the subtitle track a viewer can switch on and off. It matters for accessibility legislation and for every broadcaster, streaming platform and player vendor operating in China, because a caption track that is encoded or carried differently from what the receiver expects simply does not appear. The standard sets the protocol and the architecture of the captioning system, then the three things that have to be fixed for interoperability: the coding of the caption content, including the character repertoire, the styling and positioning attributes and the timing model; the storage of captions, that is how they are held in a file alongside the media; and the transmission of captions, principally within an MPEG-2 transport stream, with a normative annex covering carriage over non-MPEG-2 TS protocols, which is how captions travel over IP delivery. An informative annex gives the syntax structure of the caption description model. It takes effect on 1 June 2025.

This document proposes an architecture for closed captioning and specifies the encoding, storage and transmission of closed captions. This document applies to accessibility services for programs in online streaming, online TV, video on demand, TV broadcasting and emergency broadcasting. Subtitles and captions translation.

2 Normative references

The contents of the following documents constitute essential clauses of this document through normative references in this document. For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to This document.

GB/T 4880.3-2009 Language name codes Part

3 Terms and definitions

The following terms and definitions apply to this document.

3.1 closedcaptioning Text associated with audio or video content that can be turned on or off. Note 1 to entry. It is commonly used to provide a text transcription of speech or a text description of non-speech content on a video screen or other visual display device for the hearing-impaired. Note

2.Corresponding translation texts in the main language used locally can be provided for audiences in different language regions.

3.2 closedcaptioningfile Separate storage of text files for closed captions.

4 Abbreviations

The following abbreviations apply to this document.

6 Intelligent media transmission ISO / IEC 14496-

12 Information technology - Coding of audio and video objects - Part 12: ISO base media file format tions)