This document specifies a mechanism for transporting analog vertical blanking interval (VBI) information in compressed digital television bitstreams that use the MPEG-2 Transport Stream format. The VBI data so conveyed is intended to be used to generate the appropriate waveforms for insertion into the VBI of SMPTE 170M (NTSC) video output, or acted upon directly by a receiving device. This mechanism is independent of the coding layer and therefore may be used for any coding technology where carriage in an MPEG-2 PES packet format has been defined (e.g., MPEG-2 Video, MPEG-4 AVC, or SMPTE VC-1).
This design is intended to address the carriage of legacy analog VBI in digital devices such as video encoders, consumer decoders (set-top boxes and televisions), and edge decoders. It is constrained to the output video format of NTSC. However, this does not preclude the carriage in combination with other intermediate video formats or frame rates (which may be present as a result of video format conversion by an encoder).
This document extends the syntax and semantics of ETSI EN 300 472 and ETSI EN 300 468. It adds data formats in the private data code point space.
This document does not define the carriage of CEA-608 Line 21 Services, CEA-708 DTV Closed Captioning, or generic analog VBI waveforms. For Cable Television systems, refer to ANSI/SCTE 20 (legacy closed captions) and ANSI/SCTE 21 (closed captions and Luma PAM waveform). For ATSC terrestrial broadcasting systems, refer to ATSC A/53, Part 4.