Report ITU-R BT.2448-1 (09/2025) Technical realisation of signing in digital television
Foreword
Policy on Intellectual Property Right (IPR)
TABLE OF CONTENTS
1 Introduction
2 Open signing versus closed signing
3 Methods of providing closed signing
     3.1 Delivery of video streams of signers (real persons or avatars)
          3.1.1 Selection of an alternative video signal
          3.1.2 Reception of the signer video only (parallel to the TV broadcasting signal)
          3.1.3 Technical realisation of a virtual signer using video glasses
     3.2 Generation of avatars
     3.3 Generation of avatars at receiver side
          3.3.1 Closed caption streaming for automatic translation and adaptation to sign language
          3.3.2 Sign language gloss stream
          3.3.3 Sign language motion stream
     3.4 Sign-language Computer Graphic system using mobile devices in Hybridcast service
     3.5 Single screen closed signing using IBB
     3.6 Conclusions on methods of providing closed signing
References
Annex  Representation of the signer video on the main TV screen (example Japan)
1 Introduction
2 Size and position of a signer
3 Frame rate to reproduce signer’s motion
4 Speed and synchronization of signing with main video
5 Example of signing information service through the Internet
6 Conclusion