SMPTE 334-1-2007

The following suite of SMPTE Engineering Documents defines the carriage of Closed Caption data in production and distribution television systems:

SMPTE 334-1 Vertical Ancillary Data Mapping of Caption Data and Other Related Data
SMPTE 334-2 Caption Distribution Packet (CDP) Definition
SMPTE RP 2007 Closed-Caption CDP and "Grand Alliance" Serial Interfaces for DTV
SMPTE EG 43 System Implementation of CEA-708B and CEA-608-B Closed Captioning

Users should note that the data described in this standard may also be transported in KLV format according to SMPTE 336M, or via other means.

This standard defines a method of mapping closed captioning and certain other related data services into the 10-bit vertical ancillary ("VANC") data space. It specifies the structure of packets carrying CEA-708, as well as CEA-608 closed captioning data, time code data, and ATSC A/65 closed caption descriptor information, which may be carried in vertical ancillary data space, via serial data communications interfaces, or via other means.

The related data services include data broadcast services intended for the public as well as broadcaster internal control and communications.