ISO/IEC 13818-6:1998/Amd 3:2001

INTERNATIONAL ISO/IEC
STANDARD 13818-6
First edition
1998-09-01
AMENDMENT 3
2001-08-15
Information technology — Generic coding
of moving pictures and associated audio
information —
Part 6:
Extensions for DSM-CC
AMENDMENT 3: Transport buffer model in
support of synchronized user-to-network
download protocol
Technologies de l'information — Codage générique des images animées et
des informations sonores associées —
Partie 6: Extensions pour DSM-CC
AMENDEMENT 3: Modèle de tampon de transport en support du protocole
de chargement utilisateur-réseau synchronisé

Reference number
ISO/IEC 13818-6:1998/Amd.3:2001(E)
©
ISO/IEC 2001
ISO/IEC 13818-6:1998/Amd.3:2001(E)
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ISO/IEC 13818-6:1998/Amd.3:2001(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission)
form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC
participate in the development of International Standards through technical committees established by the
respective organization to deal with particular fields of technical activity. ISO and IEC technical committees
collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in
liaison with ISO and IEC, also take part in the work.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this Amendment may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
Amendment 3 to International Standard ISO/IEC 13818-6:1998 was prepared by Joint Technical Committee
ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and
hypermedia information.
© ISO/IEC 2001 – All rights reserved iii

ISO/IEC 13818-6:1998/Amd.3:2001(E)

Information technology — Generic coding of moving pictures and
associated audio information — Part 6: Extensions for DSM-CC

AMENDMENT 3: Transport buffer model in support of synchronized
user-to-network download protocol
Add the following new subclause:
9.2.9 T-STD buffer model for synchronized download protocol
9.2.9.1 Introduction
The MPEG-2 Transport System Target Decoder (T-STD) buffer model is defined for the Synchronized Download
protocol. The buffer model includes a secondary multiplexing stage based on the table_id_extension field of the DSM-
CC section structure. The secondary multiplexing stage allows multiple data modules of a single program element to be
independently synchronized.
A secondary channel is referenced as a data module channel. The table_id_extension field conveys a copy of the
moduleId of the data module. Each data module channel is identified by the moduleId value shared by all data modules
conveyed in this data module channel.
The primary, conventional multiplexing stage uses the MPEG-2 Transport Stream packet’s PID value to forward the
packet payloads to their respective smoothing buffer. The payloads of the Transport Stream packets are all portions of
DSM-CC sections of a program element of stream_type value 0x14. The DSM-CC sections convey Download Control
messages or Download Data messages. Download control messages are conveyed in sections with table_id value 0x3B
while Download Data messages are conveyed in sections with table_id value 0x3C. The section_number field identifies
the block number of the data module conveyed in the section. The payloads of the DSM-CC section sharing the same
table_id, table_id_extension and version_number field values are re-assembled in-order in the receiver to reconstruct
the synchronized data modules.
9.2.9.2 Definitions
Table 9-7 below defines the DSM-CC section payload as the bytes between the section header bytes and the CRC32 or
checksum bytes at the end of the section. The concept of DSM-CC section payload is used in the definition of the
T-STD for the Synchronized Download protocol.
© ISO/IEC 2001 – All rights reserved
ISO/IEC 13818-6:1998/Amd.3:2001(E)
Table 9-7 DSM-CC Section Format
Syntax No. of bits Mnemonic
DSMCC_section(){
table_id 8 uimsbf
section_syntax_indicator 1 bslbf
complement_indicator 1 bslbf
reserved 2 bslbf
section_length 12 uimsbf
table_id_extension 16 uimsbf
reserved 2 bslbf
version_number 5 uimsbf
current_next_indicator 1 bslbf
section_number 8 uimsbf
last_section_number 8 uimsbf
DSM-CC section payload
if(section_syntax_indicator == ‘0’) {
checksum 32 uimsbf
}
else {
CRC_32 32 rpchof
}
}
DSM-CC section header bytes shall correspond to the first 8 bytes of the DSM-CC section (from the table_id field to
the last_section_number field included) and the last 4 bytes of the section (checksum or CRC_32 field). The section
payload bytes are the bytes starting immediately following the last_section_number field and up to the field
immediately preceding the checksum or CRC_32 field.
A DSM-CC section payload includes a Download message header and a Download message. In the case of a Download
Control message (table_id 0x3B), the message header is a dsmccMessageHeader structure. In the case of a Download
Data message (table_id 0x3C), the message header is a dsmccDownloadDataHeader structure and the Download
message is a DownloadDataBlock message. The payload of a DownloadDataBlock message shall be referenced as the
Download data message payload. The payload of the DownloadDataBlock message shall not include the moduleId,
moduleVersion, reserved and blockNumber fields at the beginning of the message. The Download Data Message
payload represents a portion of a synchronized data module.
9.2.9.3 Data module channels
The secondary multiplexing/de-multiplexing stage operates on the table_id_extension fields of DSM-CC sections with
tab
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