EG 43:2009 - SMPTE Engineering Guideline - System Implementation of CEA-708 and CEA-608 Closed Captioning and Program-Related Data

The primary purpose of this guideline is to provide guidance for system implementation of closed captioning for DTV as defined in CEA-708, concentrating on different techniques that are required for DTVCC implementation when compared to CEA-608 captioning systems for NTSC. It also provides guidance on distribution of certain program-related data carried in the CEA-608 data construct. It identifies the relevant standards that exist for different parts of the system and, where possible, indicates guidelines for areas that are not standardized. — This guideline describes methods that can be used to support the various links in the chain from caption creation through to emission. Consideration is given to systems that support captioning for SD and HD program material, which can originate and/or be distributed in standard formats as used in broadcasting and related facilities. While CEA-708 refers specifically to DTV implemented for mainstream ATSC broadcast systems, techniques described herein are applicable for programming for other DTV environments such as ATSC Mobile DTV and cable or satellite distribution. — In this guideline, transport for distribution of DTVCC within the broadcast plant is based primarily on the use of SMPTE 334-1, which define a method of embedding DTVCC and other data services in the vertical ancillary (VANC) data space of video signals conforming with SMPTE 292 high-definition serial digital interface (HD-SDI) or SMPTE 259M serial digital interface (SDI). HD-SDI in this guideline refers to bit-serial component 1080 or 720 line television signals. SDI in this guideline refers to bit-serial component 525-line television signals. The carriage of DTVCC over serial data links in accordance with SMPTE 333 or RP 2007 is also included, together with arrangements for distributing caption service information. Reference is made to alternative server-based methods of distributing and managing closed captioning. — A method for carriage of DTVCC caption data in an AES3 data stream is specified in SMPTE 337M. Further details of that arrangement are not described here.