Michael Borthwick CC BY-SA
Michael Borthwick, former Technical Director at RealTime Health, recounts the journey to closed caption 400 online video clips on the RealTime Health website using the W3C Timed Text format (also known as DXFP). A workflow was developed to convert colour information in the XML DFXP files between broadcast and web colour spaces.
The dialogue of different speakers can be distinguished by using different colours namely white, yellow, cyan and green. This is particularly important for off-screen dialogue. However direct conversion of text specified as 'broadcast' green will not yield text of sufficient contrast in the HTML/CSS specification as understood by web browsers.
The case study examines the resolution of the following four challenges.
SMPTE OTT Closed Captioning Presentation Transcript Page 1