ANSI SCTE 19-2018 pdf free download.Methods for Isochronous Data Services Transport
1.0 SCOPE
This document is identical to SCTE 19 2013 except for informative components which may have
been updated such as the title page, NOTICE text, headers and footers. No normative changes
have been made to this document.
This document defines a transmission format for the carriage of isochronous data services
compatible with digital multiplex bitstreams constructed in accordance with ISO/IEC 13818-1
(MPEG-2 Systems). Bit rates for the data services extend from 19.2 kbps to 9.0 Mbps.
2.0 NORMATIVE REFERENCES
2.1 The following documents contain provisions, which, through reference in this text,
constitute provisions of the standard. At the time of Subcommittee approval, the
editions indicated were valid. All standards are subject to revision; and while parties
to any agreement based on this standard are encouraged to investigate the possibility
of applying the most recent editions of the documents listed below, they are reminded
that newer editions of those documents may not be compatible with the referenced
version.
[1] ITU-T Rec. H. 222.0 | ISO/IEC 13818-1:2007, Information TechnologyCoding of moving
pictures and associated audio-Part 1: Systems.
3.0 COMPLIANCE NOTATION
“SHALL” This word or the adjective “REQUIRED” means that the item is an absolute requirement of this specification. “SHALL NOT” This phrase means that the item is an absolute prohibition of this specification. “SHOULD” This word or the adjective “RECOMMENDED” means that there may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood and the case carefully weighted before choosing a different course. “SHOULD NOT” This phrase means that there may exist valid reasons in particular circumstances when the listed behavior is acceptable or even useful, but the full implications should be understood and the case carefully weighed before implementing any behavior described with this label. “MAY” This word or the adjective “OPTIONAL” means that this item is truly optional. One vendor may choose to include the item because a particular marketplace requires it or because it enhances the product, for example; another vendor may omit the same item.
5.2 Syntax Conventions and Definitions
5.2.1 Methods of Describing Bitstream Syntax
The method of describing isochronous data bitstream syntax is the same as that used in IEC/ISO 13818-1. [1] The bitstream retrieved by the decoder is specified by the syntax definitions given in Section 5.3 of this standard. As exemplified in Table 1, each data item in the bitstream appears in bold type.
5.3 Isochronous
Data Bitstream Syntax Isochronous data is carried as a Packetized Elementary Stream (PES). The PES payload, which follows the PES header specified by MPEG-2, begins with an isochronous data header, which is followed by isochronous data access units. The isochronous data header is present even when the PES header does not include a Presentation Time Stamp (PTS). Each isochronous data access unit is 16 bits (2 bytes; 1 word). Additionally, isochronous data access units are aligned with the PES syntax in that the first byte of the isochronous data header immediately follows the last byte of the PES header. Finally, isochronous data access units are aligned with transport packet payloads such that the first payload byte of an isochronous data transport packet is the first byte of an isochronous data access unit (following any adaptation, PES header, and isochronous data header fields), and the last byte of an isochronous data transport packet is the last byte of an isochronous data access unit. Stuffing bytes in the adaptation or PES header may be included to accomplish this. The syntax of isochronous data is as specified in the following paragraphs.
