SMPTE Updates SMPTE-TT Standard, Recommended Practices to Assure Interoperability
The Society of Motion Picture and Television Engineers (SMPTE) announced that the standards and recommended practices governing the SMPTE Timed Text (SMPTE-TT) caption format have been updated with critical corrections and edits that improve clarity and assure interoperability. SMPTE also has released a new recommended practice that addresses Consumer Electronics Association 708 (CEA-708) mapping.
“The updates to ST 2052-1 and RP 2052-10 correct and clarify text that could potentially lead to interoperability issues,” said Peter Symes, director of standards and engineering at SMPTE. “It is important that anyone using the 2010 versions of these documents be aware of these changes to SMPTE-TT.”
Adopted by the FCC as a “safe harbor interchange and delivery format,” the SMPTE-TT standard provides a means by which closed-captioning may be made available to the greatest number of media consumers. The updated SMPTE-TT documents, available for free at www.smpte.org/standards as a public service, facilitate compliance with the Twenty-First Century Communications and Video Accessibility Act of 2010 (CVAA) that the FCC began implementing on Jan. 1, 2014.
For previously broadcast over-the-air programming, the CVAA mandates that consumers have access to closed captions via almost every type of device — including a smartphone, tablet, personal computer, and television set-top box — that is capable of receiving or playing back video programming. This mandate affects TV stations, cable systems, broadcast and cable networks, streaming online video services, and virtually every other professional video program producer that makes television programming available online.
SMPTE ST 2052-1, the standard governing SMPTE-TT, has been updated to allow tunneled data to be located in places other than in the head of the document and to include recommendations about timebase. Updates to SMPTE RP 2052-10, the recommended practice that addresses CEA-608 mapping for conversion to SMPTE-TT, include the addition of an extensive example of real-world caption translation and clarification of the XDS metadata. In both documents, XML schema has been separated from prose, which itself has been improved and made more precise.
The new document in the SMPTE-TT family is RP 2052-11, the recommended practice that specifies mapping of the enhanced captioning data defined by CEA-708 into the SMPTE-TT format.