By Authority Of

THE UNITED STATES OF AMERICA

Legally Binding Document
By the Authority Vested By Part 5 of the United States Code § 552(a) and
Part 1 of the Code of Regulations § 51 the attached document has been duly
INCORPORATED BY REFERENCE and shall be considered legally
binding upon all citizens and residents of the United States of America.
HEED THIS NOTICE: Criminal penalties may apply for noncompliance.

e
Document Name: SCTE 54: Digital Video Service Multiplex and Transport
System Standard for Cable Television
CFR Section(s): 47 CFR 15.123(b)(3)

Standards Body: Society of Cable Telecommunications Engineers

Official Incorporator:
THE EXECUTIVE DIRECTOR
OFFICE OF THE FEDERAL REGISTER
WASHINGTON, D.C.
 ENGINEERING COMMITTEE
Digital Video Subcommittee

AMERICAN NATIONAL STANDARD

ANSI/SCTE 54 2009

Digital Video Service Multiplex

and Transport System Standard
for Cable Television
 NOTICE

The Society of Cable Telecommunications Engineers (SCTE) Standards are intended to serve the
public interest by providing specifications, test methods and procedures that promote uniformity
of product, interchangeability and ultimately the long term reliability of broadband
communications facilities. These documents shall not in any way preclude any member or non-
member of SCTE from manufacturing or selling products not conforming to such documents, nor
shall the existence of such standards preclude their voluntary use by those other than SCTE
members, whether used domestically or internationally.

SCTE assumes no obligations or liability whatsoever to any party who may adopt the Standards.
Such adopting party assumes all risks associated with adoption of these Standards, and accepts
full responsibility for any damage and/or claims arising from the adoption of such Standards.

Attention is called to the possibility that implementation of this standard may require the use of
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this standard have been requested to provide information about those patents and any related
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All Rights Reserved

© Society of Cable Telecommunications Engineers, Inc. 2009

140 Philips Road
Exton, PA 19341

i
 DIGITAL VIDEO SERVICE MULTIPLEX AND TRANSPORT
SUBSYSTEM STANDARD FOR CABLE TELEVISION
Table of Contents
1. SCOPE .............................................................................................................................................1

2. NORMATIVE REFERENCES ......................................................................................................1

3. DEFINITIONS ................................................................................................................................2

3.1 Compliance notation 2

3.2 Acronyms and Abbreviations 2

4. SYSTEM OVERVIEW ...................................................................................................................3

5. SPECIFICATION ...........................................................................................................................4

5.1 MPEG-2 Systems standard 4

5.1.1 Video T-STD 4
5.1.2 Audio T-STD 5
5.2 Identification of MPEG-2 Private Ranges 5
5.2.1 MPEG-2 Registration Descriptor 5
5.2.2 Program Identifier 5
5.2.3 Audio Elementary Stream Identifier 5
5.2.4 Other Program Element Identifiers 6
5.3 Audio Constraints 6
5.4 Video Constraints 6
5.5 Constraints on PSI 6
5.6 PES constraints 7
5.6.1 Audio PES constraints 7
5.7 Services and features 8
5.7.1 System information and program guide 8
5.7.2 Emergency alerts 10
5.7.3 Specification of private data services 10
5.7.4 MPEG-2 Still Pictures 10
5.8 Assignment of identifiers 10
5.8.1 Table IDs 10
5.8.2 Stream Types 11
5.8.3 Descriptors 12
5.9 Extensions to the MPEG-2 Systems specification 17
5.9.1 Scrambling control 17
5.10 Service Acquisition Considerations (Informative) 17

ii
6. FEATURES OF ISO/IEC 13818-1 NOT SUPPORTED BY THIS STANDARD ....................18

6.1 Program streams 18

7. TRANSPORT ENCODER OUTPUT BIT RATES....................................................................18

List of Figures
Figure 4.1 Sample organization of functionality in a transmitter-receiver pair for a single
program. 4

List of Tables
Table 5.1 Maximum cycle time for the STT, MGT, CVCT and RRT 9
Table 5.2 Maximum rate for each PSIP packet stream 9
Table 5.3 Table ID Ranges and Values (Informative) 11
Table 5.4 Stream Type Codes 12
Table 5.5 Descriptors 13
Table 5.6 – ATSC Private Information Descriptor 16
Table 5.7 PID Assignment 17
Table 5.8 Transport Scrambling Control Field 17

iii
 DIGITAL VIDEO SERVICE MULTIPLEX AND TRANSPORT
SUBSYSTEM STANDARD FOR CABLE TELEVISION

1. SCOPE
This document describes the transport subsystem characteristics and normative
specifications of the in-band Service Multiplex and Transport Subsystem Standard for Cable
Television.1

2. NORMATIVE REFERENCES
The following documents contain provisions which in whole or in part, through reference
in this text, constitute provisions of this Standard. At the time of publication, the editions
indicated were valid. All standards are subject to revision and amendment, and parties to
agreements based on this Standard are encouraged to investigate the possibility of applying the
most recent editions of the documents listed below.
1. ANSI/SCTE 07 2006 , Digital Video Transmission Standard for Cable Television.
2. ATSC A/52A (2001), Digital Audio Compression (AC-3).
3. ATSC A/53B (2001), ATSC Digital Television Standard.
4. ATSC A/65A (2000), Program and System Information Protocol (PSIP) for
Terrestrial Broadcast and Cable.
5. ATSC A/90 Data Broadcast Standard (2000).
6. CEA-708-B, Digital Television (DTV) Closed Captioning (1999)
7. EIA/CEA-766-A (2000), U.S. and Canadian Rating Region Tables (RRT) and
Content Advisory Descriptors for Transport of Content Advisory Information Using
ATSC A/65A Program and System Information Protocol (PSIP).
8. ISO/IEC IS 13818-1, (2000), “Information Technology—Generic coding of moving
pictures and associated audio—Part1: Systems.”
9. ISO/IEC IS 13818-2, (2000), “Information Technology—Generic coding of moving
pictures and associated audio—Part 2: Video.”
10. ISO/IEC 13818-6, (1998), “Information Technology—Generic coding of moving
pictures and associated audio—Part 6: Digital Storage Media Command & Control,”
Chapter 2, 4-7, 9, 11.
11. ANSI-J-STD-042-2002, Emergency Alert Message for Cable.
12. ANSI/SCTE 19 2006 , Standard Methods for Isochronous Data Services Transport.
13. ANSI/SCTE 27 2003 , Subtitling Methods for Broadcast Cable.

1
Informative note: This standard applies only to Transport Streams transmitted on cable using 64- or 256-QAM
modulation in accordance with ANSI/SCTE 07 2000 Digital Video Transmission Standard for Cable Television.

1
 14. ANSI/SCTE 53 2008 , Methods for Asynchronous Data Services Transport.
15. ANSI/SCTE 42 2008, IP Multicast for Digital MPEG Networks.

3. DEFINITIONS

3.1 Compliance notation

As used in this document, “shall” denotes a mandatory provision of the standard.
“Should” denotes a provision that is recommended but not mandatory. “May” denotes a feature
whose presence does not preclude compliance that may or may not be present at the option of the
implementer.

3.2 Acronyms and Abbreviations

The following acronyms and abbreviations are used within this specification:
ASTD Ancillary Service Target Decoder
ATSC Advanced Television Systems Committee
CA Conditional Access
CAT Conditional Access Table
CRC Cyclic Redundancy Check
CVCT Cable Virtual Channel Table
DET Data Event Table
DOCSIS Data Over Cable Service Interface Specification2
DSM-CC Digital Storage Media Command and Control
DST Data Service Table
DTS Decoding Time Stamp
DVB Digital Video Broadcasting
DVS Digital Video Subcommittee
EA Emergency Alert
ECM Entitlement Control Message
EIT Event Information Table
ES Elementary Stream
ETT Extended Text Table
IEC International Electrotechnical Commission
ISO International Organization for Standardization
MGT Master Guide Table
MPEG Moving Picture Experts Group
MRD MPEG-2 Registration Descriptor
PAT Program Association Table
PES Packetized Elementary Stream
PID Packet Identifier
PMT Program Map Table

2
See http://www.cablemodem.com/ or ANSI/SCTE 22-1 2002.

—2—
PSI Program Specific Information
PSIP Program and System Information Protocol
PTS Presentation Time Stamp
QAM Quadrature Amplitude Modulation
RRT Rating Region Table
SI Service Information
STT System Time Table
TS Transport Stream
T-STD Transport Stream System Target Decoder
TVCT Terrestrial Virtual Channel Table
VBV Video Buffering Verifier

4. SYSTEM OVERVIEW
The transport format and protocol for the Service Multiplex and Transport Subsystem
Standard for Cable Television is a compatible subset of the MPEG-2 Systems specification
defined in ISO/IEC 13818-1. It is based on a fixed-length packet Transport Stream approach
which has been defined and optimized for digital television delivery applications.
As illustrated in Figure 4.1, the transport function resides between the application (e.g.,
audio or video) encoding and decoding functions and the transmission subsystem. The encoder’s
transport subsystem is responsible for formatting the coded elementary streams and multiplexing
the different components of the program for transmission. The receiver is responsible for
recovering the elementary streams for the individual application decoders and for the
corresponding error signaling. The transport subsystem also incorporates other higher protocol
layer functionality related to synchronization of the receiver.
One approach to system multiplexing approach may be to consider it a combination of
multiplexing at two different layers. In the first layer, single program Transport Streams are
formed by multiplexing Transport Stream (TS) packets from one or more Packetized Elementary
Stream (PES) and/or private section (ISO/IEC 13818-1 [8] Table 2-30) sources. In the second
layer, a single program Transport Stream forms (or two or more may be are combined to form) a
service multiplex (also known as a multi-program Transport Stream in the MPEG-2 Systems
standard, and a digital television standard multiplexed bit stream in this SCTE standard).
Program Specific Information (PSI) identifies programs and the components of programs.
Not shown explicitly in Figure 4.1, but essential to the practical implementation of this
Standard, is a control system that manages the transfer and processing of the elementary streams
from the application encoders. The rules followed by this control system are not a part of this
Standard. The output of the control system implementation shall conform to the MPEG-2
Transport Stream coding as specified in ISO/IEC 13818-1 [8] with the additional constraints
specified in this Standard.

—3—
 Transmitter

(video, audio, data, etc.)

Sources for encoding

packetization and
multiplexing
Application

Transport
Encoders
* Mod-
* ulator
*
* Transport
Stream
elementary
streams, private
sections, or PES
System Time

Transmission
Clock

Format
Receiver

depacketization and
demultiplexing
Presentation

Application

Transport
Decoders

Demod-
*
* ulator
* Transport
*
elementary Stream with
streams, private error
sections, or PES signaling
with error
signaling

clock
System Time Clock control

Figure 4.1 Sample organization of functionality in a transmitter-receiver pair for a single

program.

5. SPECIFICATION
This Section constitutes the normative specification for the transport subsystem of the
Service Multiplex and Transport Subsystem Standard for Cable Television. The syntax and
semantics of the specification conform to ISO/IEC 13818-1, subject to the constraints and
conditions specified in this Standard. This Section of the Standard describes the coding
constraints that apply to the use of the MPEG-2 systems specification in the digital television
system.

5.1 MPEG-2 Systems standard

The Transport Stream shall comply with all normative elements of ISO/IEC 13818-1 [8].
Certain constraints against the MPEG-2 Systems standard apply as defined in this document.

5.1.1 Video T-STD

The video Transport Stream System Target Decoder (T-STD) shall be based on Section
2.4.2.3 of ISO/IEC 13818-1 and follows the constraints for the level encoded in the video
elementary stream.

—4—
5.1.2 Audio T-STD
The audio T-STD shall be defined as specified in Section 3.6 of Annex A of ATSC
Standard A/52, and as further constrained in Annex B of ATSC Standard A/53.

5.2 Identification of MPEG-2 Private Ranges

ATSC coordinates code point assignments in the MPEG-2 user-private range and SCTE
may define code points within this coordinated range.

5.2.1 MPEG-2 Registration Descriptor

Under circumstances as defined below, this Standard uses the MPEG-2 Registration
Descriptor described in Section 2.6.8 and 2.6.9 of ISO/IEC 13818-1 [8] to identify the contents
of programs and program elements to decoding equipment. No more than one MPEG-2
Registration Descriptor shall appear in any given descriptor loop.

5.2.2 Program Identifier

Subject to the restriction in Sec. 5.2.1 against multiple MPEG-2 Registration Descriptors
(MRD), as defined in Section 2.6.8 and 2.6.9 of ISO/IEC 13818-1 [8], in a given descriptor loop,
an MRD with any registered value of format_identifier may be present in the descriptor loop
immediately following the program_info_length field of the TS_program_map_section(). The element(s)
scoped by the MRD are described by the owner of the registered value in the format_identifier field.
When an MRD with format identifier values 0x5343 5445 (“SCTE” in ASCII), or 0x4741
3934 (“GA94” in ASCII), is present in the descriptor loop immediately following the
program_info_length field of the TS_program_map_section() describing the program, the program elements
are as described by SCTE or ATSC standards respectively.
Informative note: The absence of an MPEG-2 Registration Descriptor having a value of
0x5343 5445 or 0x4741 3934 should not be taken as an indication that the corresponding
program does or does not conform to ATSC and/or SCTE standards.

5.2.3 Audio Elementary Stream Identifier

Presence of audio program elements that conform to ATSC and SCTE standards may be
indicated by use of an MPEG-2 Registration Descriptor (as defined in Section 2.6.8 and 2.6.9 of
ISO/IEC 13818-1 [8]) placed in the descriptor loop immediately following the ES_info_length field
in the TS_program_map_section() for each such audio program element. The format_identifier field of this
MPEG-2 Registration Descriptor, when used, shall have a format_identifier field value of 0x4143
2D33 (“AC-3” in ASCII).
Informative note: The absence of an MPEG-2 Registration Descriptor having a value of
0x4143 2D33 should not be taken as an indication that the corresponding program does or does
not conform to ATSC and/or SCTE standards.

—5—
5.2.4 Other Program Element Identifiers

Any program element carrying content not described by an approved ATSC or SCTE
standard shall be identified with an MPEG-2 Registration Descriptor (as defined in Section 2.6.8
and 2.6.9 of ISO/IEC 13818-1 [8]). The format_identifier field of the MPEG-2 Registration
Descriptor shall be registered with the SMPTE Registration Authority, LLC2. The descriptor
shall be placed in the descriptor loop immediately following the ES_info_length field in the
TS_program_map_section() for each such non-standard program element.
The presence of an MPEG-2 Registration Descriptor in any descriptor loop shall not affect
the meaning of any other descriptor(s) in the same descriptor loop. The ATSC Private
Information Descriptor (defined in section 5.8.3.8) shall be the standard method to carry
descriptor-based information associated with a private entity.
An MPEG-2 Registration Descriptor shall be placed in the descriptor loop immediately
following the ES_info_length field in the TS_program_map_section() for each program element having a
stream_type value in the user private range, 0xC4 to 0xFF, to establish the private entity associated
with that program element.
An MPEG-2 Registration Descriptor present in the program information descriptor loop
in the TS_program_map_section() (the descriptor loop immediately following the program_info_length field)
shall apply to all program elements described in the TS_program_map_section(). An MPEG-2
Registration Descriptor may be present in the program information descriptor loop of the
TS_program_map_section() only if it is applicable to all program elements described in that
TS_program_map_section().

5.3 Audio Constraints

If a program contains one or more audio components, at least one shall be a complete
main audio service (CM) as defined by ATSC Standard A/52A, including all voice-overs and
emergency messages, when these are present in the Transport Stream.

5.4 Video Constraints

MPEG-2 programs shall be constrained to carry at most one MPEG-2 video Elementary
Stream component.

5.5 Constraints on PSI

The program constituents for all programs are described in the PSI according to ISO/IEC
13818-1 [8]. The following constraints shall apply to the PSI information:
• Transport Stream packets identified by a particular PMT_PID value shall be constrained to
carry only one program definition, as described by a single TS_program_map_section().
• The Transport Stream shall be constructed such that the time interval between the byte
containing the last bit of the TS_program_map_section() containing television program
information and successive occurrences of the same TS_program_map_section() shall be less
than or equal to 400 milliseconds.

2
The ISO/IEC-designated registration authority for the format_identifier is SMPTE Registration Authority,
LLC. See (http://www.smpte-ra.org/html).

—6—
 • The program_number values shall be associated with the corresponding PMT_PIDs in the
Program Association Table (PAT). The Transport Stream shall be constructed such that
the time interval between the byte containing the last bit of the program_association_section()
and successive occurrences of the program_association_section() shall be less than or equal to
100 milliseconds. However, when program_association_section()s, CA_section()s, and
TS_program_map_section()s are approaching their maximum allowed sizes, the potential exists
to exceed the 80,000 bps rate specified in ISO/IEC 13818-1 Sec. 2.4.2.3. In cases where
the table section sizes are such that the 100 millisecond repetition rate of the
program_association_section() would cause the 80,000 bps maximum rate to be exceeded, the
time interval between the byte containing the last bit of the program_association_section() may
be increased but in no event shall exceed 140 milliseconds, so that under no
circumstances the limit of 80,000 bps is exceeded.
• Adaptation headers shall not occur in TS packets identified by a program_map_PID value for
purposes other than for signaling with the discontinuity_indictor that the version_number (Section
2.4.4.5 of ISO/IEC 13818-1 [8]) may be discontinuous.
• Adaptation headers shall not occur in TS packets identified by PID 0x0000 (the PAT
PID) for purposes other than for signaling with the discontinuity_indicator that the version_number
(Section 2.4.4.5 of ISO/IEC 13818-1 [8]) may be discontinuous.
• Private table sections in addition to Program Map Tables may be present in TS packets
PMT_PID identified by a program_map_PID value.

5.6 PES constraints

Packetized Elementary Stream syntax and semantics shall be used to encapsulate the
audio and video elementary stream information according to ISO/IEC 13818-1. The Packetized
Elementary Stream syntax is used to convey the Presentation Time-Stamp (PTS) and Decoding
Time-Stamp (DTS) information required for decoding audio and video information with
synchronism. This Section describes the coding constraints for this system layer.
Within the PES packet header, the following restrictions shall apply:
• PES_scrambling_control shall be coded as ‘00’.
• ESCR_flag shall be coded as ‘0’.
• ES_rate_flag shall be coded as ‘0’.
• PES_CRC_flag shall be coded as ‘0’.
Within the PES packet extension, the following restrictions shall apply.
• PES_private_data_flag shall be coded as ‘0’.
• pack_header_field_flag shall be coded as ‘0’.
• program_packet_sequence_counter_flag shall be coded as ‘0’.
• P-STD_buffer_flag shall be coded as ‘0’.

5.6.1 Audio PES constraints

The audio decoder may be capable of simultaneously decoding more than one elementary
stream containing different program elements, and then combining the program elements into a
complete program. In this case, the audio decoder may sequentially decode audio frames (or
audio blocks) from each elementary stream and do the combining (mixing together) on a frame

—7—
(or block) basis. In order to have the audio from the two elementary streams reproduced in exact
sample synchronism, it shall be required for the original audio elementary stream encoders to
have encoded the two audio program elements frame synchronously; i.e., if audio program 1 has
sample 0 of frame n at time t0, then audio program 2 should also have frame n beginning with its
sample 0 at the identical time t0. If the encoding is done frame synchronously, then matching
audio frames should have identical values of PTS.
If PES packets from two audio services that are to be decoded simultaneously contain
identical values of PTS then the corresponding encoded audio frames contained in the PES packets
should be presented to the audio decoder for simultaneous synchronous decoding. If the PTS
values do not match (indicating that the audio encoding was not frame synchronous) then the
audio frames which are closest in time may be presented to the audio decoder for simultaneous
decoding. In this case the two services may be reproduced out-of-sync by as much as 1/2 of a
frame time (which is often satisfactory, e.g., a voice-over does not require precise timing).
The value of stream_id for AC-3 audio shall be 1011 1101 (private_stream_1).

5.7 Services and features

5.7.1 System information and program guide

Transport Streams containing one or more unscrambled programs that include navigation
data shall include service information defined in 5.7.1.1 below, describing the unscrambled
programs. Timing aspects of the delivery of service information tables are defined in Sec.
5.7.1.2. The policy question of who is responsible for creating this service information (and its
accuracy, completeness, formatting, and compliance with A/65A) is outside the scope of this
standard.
Informative note: In the absence of a functioning POD module, receivers are expected to
support navigation only to unscrambled services that are referenced in an in-band Virtual
Channel Table present in the Transport Stream that carries the program.
When present, system information shall be formatted according to the structure and
syntax described in ATSC A/65A [4]. System information data, when present, shall be
transported in TS packets of PID 0x1FFB (the base_PID per [4]). PID 0x1FFB shall be reserved
exclusively for this purpose.
At the option of the cable operator, data supporting construction of an Electronic
Program Guide in the receiver in conformance with [4] may also be present.
Informative note: The following sub-sections describe the structure and syntax for system
information, when present.

5.7.1.1 Service information tables

When present, the service information shall include the following tables at a minimum:
the Master Guide Table (MGT), System Time Table (STT), and the Cable Virtual Channel Table
(CVCT) or the Terrestrial Virtual Channel Table (TVCT). If any Program Map Table or Event
Information Table on the Transport Stream includes a content_advisory_descriptor() quoting a
rating_region other than region 0x01 (U.S. plus possessions), the Rating Region Table (RRT)

—8—
describing that region shall be transmitted. Delivery of the RRT corresponding to region 0x01
(U.S. and possessions) is optional because this table is standardized in EIA/CEA-766-A [7].
Those transmitted tables shall describe the unscrambled digital services multiplexed in
the Transport Stream carrying those tables. The tables may optionally include information about
analog channels, scrambled channels, as well as other digital channels available in different
Transport Streams.
The 10-bit major_channel_number and minor_channel_number fields in the Cable Virtual Channel
table represent either a two-part or a one-part virtual channel number associated with the virtual
channel being defined. The one- or two-part number acts as the user’s reference number for the
virtual channel. Some channels in the CVCT may be represented with a one-part number while
others are represented with two-part numbers.
To specify a two-part channel number both the major_channel_number and the
minor_channel_number fields shall be below 1000. To specify a one-part channel number, the six most
significant bits of major_channel_number shall be ‘11 1111’. Values and combinations of
major_channel_number and minor_channel_number falling outside these ranges are reserved.

The one-part channel number is a 14-bit quantity that shall be computed by the following
formula, represented in C syntax:

one_part_number = (major_channel_number & 0x00F) << 10 + minor_channel_number

Any given cable programming service may be represented either by a two-part channel
number in a CVCT or a TVCT, or by a one-part channel number in the CVCT.

5.7.1.2 System information and program guide T-STD model

Table 5.1 lists the maximum cycle time for the SI tables required for in-band cable.

Table 5.1 Maximum cycle time for the STT, MGT, CVCT and RRT

Table STT MGT CVCT RRT (when present)

Cycle time (ms) 10000 150 400 60000

Table 5.2 lists the maximum transmission rate for SI streams according to their PIDs. The
recommended maximum cycle time for EIT-0, if present, shall be 500 ms.

Table 5.2 Maximum rate for each PSIP packet stream

PID base_PID EIT_PID ETT_PID

Rate (bps) 250,000 250,000 250,000

—9—
 In cable applications, the SI streams identified by Transport Stream packets with PID
0x1FFB (base_PID) and EIT PIDs and ETT PIDs (if present) shall adhere to an T-STD model with
the following parameters:
• sb_leak_rate shall be 625 (indicating a leak rate of 250,000 bps)
• sb_size shall be 1024 (indicating a smoothing buffer size of 1024 bytes)

5.7.2 Emergency alerts

Transport Streams may include Emergency Alert information. When present, Emergency
Alert information shall conform to ANSI-J-STD-042-2002, Emergency Alert Message for Cable
[Error! Reference source not found.]. When present, the cable_emergency_alert() table section shall
be carried in TS packets with PID 0x1FFB (base_PID).

5.7.3 Specification of private data services

Private data may be transported by various means:
1. Data services—Carriage of data services including system information shall be as
documented in applicable ATSC or SCTE Standards.
2. Private program elements—The stream_type codes in the range 0xC4 to 0xFF shall be
available for stream types defined privately (not described by ATSC or SCTE Standards).
Such privately-defined program elements shall include an MPEG-2 Registration
Descriptor (see Sec. 5.2.4).
3. Adaptation fields— Private data may be transmitted within the adaptation field headers
of TS packets (Sections 2.4.3.4 and 2.4.3.5 of ISO/IEC 13818-1 [8]). Program elements
that include private data in the adaptation fields of their TS packets shall include an
MPEG-2 Registration Descriptor (see Sec. 5.2.4).

5.7.4 MPEG-2 Still Pictures

Certain services may include video elementary streams conforming to the ISO/IEC
13818-1 Still Picture Model. Any elementary stream containing still picture data shall include a
video_stream_descriptor() in accordance with ISO/IEC 13818-1 Sec. 2.6.2.

5.8 Assignment of identifiers

In this section, those identifiers and codes that shall have a fixed value are summarized.
These include stream_type values and descriptor tags. Stream_type codes for program element types
managed by the ATSC Code Points Registrar (currently assigned or available for future
assignment) shall be in the range 0x80 to 0xC3. Descriptor_tag codes managed by the ATSC Code
Points Registrar (currently assigned or available for future assignment) shall be in the range 0x40
to 0xEF.

5.8.1 Table IDs

Informative Table 5.3 lists table ID values applicable to this standard.

— 10 —
 Table 5.3 Table ID Ranges and Values (Informative)
Table ID
Value (hex) Tables PID Reference
ISO/IEC 13818-1 Sections:
0x00 PROGRAM ASSOCIATION TABLE (PAT) 0 Ref. [8]
0x01 CONDITIONAL ACCESS TABLE (CAT) 1 Ref. [8]
0x02 TS PROGRAM MAP TABLE (PMT) per PAT Ref. [8]
0x03-0x3F [ISO assigned or reserved]
User Private Sections:
0x80-0xBF [User Private]
A/65A Sections:
0xC7 MASTER GUIDE TABLE (MGT) 0x1FFB Ref. [4]
0xC8 TERRESTRIAL VIRTUAL CHANNEL TABLE (TVCT) 0x1FFB Ref. [4]
0xC9 CABLE VIRTUAL CHANNEL TABLE (CVCT) 0x1FFB Ref. [4]
0xCA RATING REGION TABLE (RRT) 0x1FFB Ref. [4]
0xCB EVENT INFORMATION TABLE (EIT) per MGT Ref. [4]
0xCC EXTENDED TEXT TABLE (ETT) per MGT Ref. [4]
0xCD SYSTEM TIME TABLE (STT) 0x1FFB Ref. [4]
Data Broadcasting Tables:
0xCE DATA EVENT TABLE (DET) per MGT Ref. [5]
0xCF DATA SERVICE TABLE (DST) per PMT Ref. [5]
0xD1 NETWORK RESOURCES TABLE (NRT) per PMT Ref. [5]
0xD2 LONG TERM SERVICE TABLE (LTST) per PMT Ref. [5]
SCTE 18 2001:
0xD8 CABLE EMERGENCY ALERT 0x1FFB Ref. [Error!
Reference
source not
found.]
0xFF ISO/IEC 13818-1 Forbidden Ref. [8]

5.8.2 Stream Types

Stream type code values shall be as indicated in Table 5.4.

— 11 —
 Table 5.4 Stream Type Codes
Value Description
0x01 ISO/IEC 11172 Video
0x02 ITU-T Rec. H.262 | ISO/IEC 13818-2 Video
0x03 ISO/IEC 11172 Audio
0x04 ISO/IEC 13818-3 Audio
0x05 ITU-T Rec. H.222.0 | ISO/IEC 13818-1 private sections
0x06 ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing private data
0x07 ISO/IEC 13522 MHEG
0x08 ITU-T Rec. H.222.0 | ISO/IEC 13818-1 DSM-CC
0x09 ITU-T Rec. H.222.0 | ISO/IEC 13818-1/11172-1 auxiliary
0x0A ISO/IEC 13818-6 type A (Multi-protocol Encapsulation)
0x0B ISO/IEC 13818-6 type B (DSM-CC U-N Messages)
0x0C ISO/IEC 13818-6 type C (DSM-CC Stream Descriptors)
0x0D ISO/IEC 13818-6 type D (DSM-CC Sections – any type, including private data)
0x0E ISO/IEC 13818-1 auxiliary
0x014 Non-streaming, synchronized data stream (Ref. [5])
0x80 Identical to ITU-T Rec. H.262 | ISO/IEC 13818-2 Video
0x81 ATSC A/53B audio (Ref. [3])
0x82 Standard subtitle (Ref. [13])
0x83 Isochronous data (Ref. [12])
0x95 Data Service Table, Network Resources Table (Ref. [5])
0xC2 Streaming, synchronized data stream (Ref. [5])
0xC3 Asynchronous data (Ref. [14])
0xC4-0xFF User Private

5.8.2.1 Video Stream Type

The stream_type codes 0x02 or 0x80 shall be used for compressed MPEG-2 video
elementary streams carried in transport packets defined by this standard. No other stream_type
codes shall be used for this purpose.

5.8.2.2 Audio Stream Type

The stream_type code 0x81 shall be used for compressed ATSC A/53B [3] audio elementary
streams carried in transport packets defined by this standard. No other stream_type codes shall be
used for this purpose.

5.8.3 Descriptors
Descriptor tag values shall be as indicated in Table 5.5.

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 Table 5.5 Descriptors
Tag Descriptor Name Where Used Reference

0x00-0x01 ISO reserved

0x02 video_stream_descriptor() PMT Ref. [8]
0x03x04 ISO defined Ref. [8]
0x05 registration_descriptor() PMT Ref. [8]
0x06-0x08 ISO defined Ref. [8]
0x09 CA_descriptor() PMT, CAT Ref. [8]
0x0A ISO_639_language_descriptor() PMT Ref. [8]
0x0B-0x0F ISO defined Ref. [8]
0x10 smoothing_buffer_descriptor() PMT Ref. [8]
0x11-0x13 ISO defined Ref. [8]
0x14 association_tag_descriptor() PMT Ref. [5]
0x15-0x3F ISO reserved
0x80 stuffing_descriptor() Anywhere Ref. [2]
0x81 AC3_audio_descriptor() PMT Ref. [2]
0x86 caption_service_descriptor() PMT, EIT Ref. [4]
0x87 content_advisory_descriptor() PMT, EIT Ref. [4]
0xA0 extended_channel_name_descriptor() VCT Ref. [4]
0xA1 service_location_descriptor() VCT Ref. [4]
0xA2 time_shifted_service_descriptor() VCT Ref. [4]
0xA3 component_name_descriptor() PMT Ref. [4]
0xA4 data_broadcast_descriptor() DET, EIT Ref. [4]
0xA5 PID_count_descriptor() DET, EIT Ref. [4]
0xA6 download_descriptor() DST Ref. [4]
0xA7 multiprotocol_encapsulation_descriptor() DST Ref. [4]
0xA8 dcc_departing_request_descriptor() DCCT Ref. [4] Amd. 1
0xA9 dcc_arriving_request_descriptor() DCCT Ref. [4] Amd. 1
0xAA rc_descriptor() PMT, EIT Ref. [4] Amd. 3
0xAC MAC_Address_List_descriptor() PMT Ref. [15]
0xAD ATSC_private_information_descriptor() Misc. Sec. 5.8.3.8
0xF0-0xFF User Private

5.8.3.1 AC-3 audio descriptor

When an Elementary Stream of stream_type 0x81 (AC-3 audio) is present in the digital
television transport stream, an AC-3 Audio Descriptor (audio_stream_descriptor()) shall be included in
the descriptor loop immediately following the ES_info_length field in the TS_program_map_section()
describing that Elementary Stream. The syntax shall be as given in Table A2 of Annex A of
ATSC Standard A/52A [2]. The following constraints shall apply to the AC-3 Audio Descriptor:
1. The value of the descriptor_tag shall be 0x81.
2. The num_channels field shall have a value in the range 1 to 13.
3. The langcod field is a reserved field. Audio language shall be indicated using an ISO 639
Language Descriptor (see Sec. 5.8.3.2 below).
4. The descriptor shall identify the type of the audio service in the bsmod field, which shall
be the same as the bsmod field in the elementary stream associated with this descriptor.

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 5. The descriptor may terminate at one of two places:
a. if describing a main audio service for which no associated services are available,
immediately following full_svc; otherwise
b. immediately prior to textlen.

Informative note: The recent ATSC A/53: 2007 Standard requires language signaling to be
placed in the extended AC-3 Audio Descriptor and changed the insertion in the PMT of the ISO
639 language descriptor from required to optional, effective March 2008. While some
broadcasters may include the ISO 639 language descriptor in addition to the extended AC-3
Audio Descriptor to signal the language of each audio service, some may not. The policy
question of who is responsible for making the PMT conform to the requirements of Section
5.8.3.2 below is outside the scope of this standard.”

5.8.3.2 ISO 639 language descriptor

The ISO 639 Language Descriptor defined in ISO/IEC 13818-1 [8] Section 2.6.18 is used
to indicate the language of audio Elementary Stream components. The ISO 639 Language
Descriptor shall be included in the descriptor loop immediately following the ES_info_length field
in the TS_program_map_section() for each Elementary Stream of stream_type 0x81 (AC-3 audio) when
the number of audio Elementary Streams in the TS_program_map_section() having the same value of
bit stream mode (bsmod in the AC-3 Audio Descriptor) is two or more.
Informative note: As an example, consider an MPEG-2 program that includes two audio
ES components: a Complete Main (CM) audio track (bsmod = 0) and a Visually Impaired (VI)
audio track (bsmod = 2). Inclusion of the ISO 639 Language Descriptor is optional for this
program. If a second CM track were to be added, however, it would then be necessary to include
ISO 639 Language Descriptors in the TS_program_map_section().
The audio_type field in any ISO 639 Language Descriptor used in this Standard shall be set
to 0x00 (meaning “undefined”).
An ISO 639 Language Descriptor may be present in the TS_program_map_section() in other
positions as well, for example to indicate the language or languages of a textual data service
program element.

5.8.3.3 Program smoothing buffer descriptor.

The Program Map Table of each program may contain a smoothing buffer descriptor
pertaining to that program in accordance with Section 2.6.30 of ISO/IEC 13818-1. During the
continuous existence of a program, the value of the elements of the smoothing buffer descriptor,
if present, shall not change.
If present the fields of the smoothing buffer descriptor shall meet the following
constraints:
• The field sb_leak_rate shall be allowed to range up to the maximum transport rates specified
in Section 7.

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 • The field sb_size shall have a value less than or equal to 2048. The size of the smoothing
buffer is thus 2048 bytes.

5.8.3.4 Video stream descriptor

Any elementary stream containing still picture data shall include a video_stream_descriptor()
in accordance with ISO/IEC 13818-1 Sec. 2.6.2 in the TS_program_map_section() describing that
elementary stream.

5.8.3.5 Component name descriptor

Whenever a service includes two or more audio components labelled with the same
ISO_639_language_code (in the ISO 639 Language Descriptor) and bsmod (in the AC-3 Audio
Descriptor), a unique component_name_descriptor() (as defined in Sec. 6.7.8 of ATSC A/65A [4]) shall
be placed into the descriptor loop immediately following the ES_info_length field in the
TS_program_map_section() to describe each such audio component.

Whenever a service includes an audio component whose bit stream mode (bsmod, as
indicated in the AC-3 Audio Descriptor) is music and effects (ME) (bsmod = 1), and the
component is a full service suitable for presentation (as indicated by the full_svc flag in the AC-3
Audio Descriptor being set) a unique component_name_descriptor() should be placed into the
Elementary Stream information (inner) loop of the TS_program_map_section() to describe that
component.

5.8.3.6 Caption service descriptor

When caption services are delivered within the picture user_data() construct defined in
ATSC A/53B [3] Annex A, the caption_service_descriptor(), as defined in Sec. 6.7.3 of ATSC A/65A
[4], shall be present in:
• the TS_program_map_section() (as defined in ISO/IEC 13818-1 sections 2.4.4.8 and 2.4.4.9 [8])
in the ES_info descriptor loop for the video program element; and
• the EIT-0 for that program, when EIT-0 is present in the Transport Stream.

5.8.3.7 Content advisory descriptor

For current programs, the content_advisory_descriptor(), as defined in ATSC A/65-A [4] section
6.7.4, when present, shall be carried in the TS_program_map_section() (as defined in ISO/IEC 13818-1
sections 2.4.4.8 and 2.4.4.9 [8]) in the descriptor loop immediately following the program_info_length
field. When content advisories are present for a current program and EIT-0 is present in the
Transport Stream, the content_advisory_descriptor() shall be present in EIT-0 for that program. Content
advisories for future programs may be carried in the appropriate EIT, if EIT data is present in the
Transport Stream. The only rating regions currently defined for cable use are Region One, the
US plus possessions (value 0x01 for the rating_region field) and Region Two, Canada (value 0x02
for the rating_region field).

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5.8.3.8 ATSC private information descriptor

The ATSC_private_information_descriptor() provides a method to carry and unambiguously label

private information. More than one ATSC_private_information_descriptor() may appear within a single
descriptor loop. Table 5.6 defines the bit-stream syntax of the ATSC_private_information_descriptor().

Table 5.6 – ATSC Private Information Descriptor

Syntax Bits Format
ATSC_private_information_descriptor() {
descriptor_tag 8 0xAD
descriptor_length 8 uimsbf
format_identifier 32 uimsbf
for (i = 0; i < N; i++) {
private_data_byte 8 bslbf
}
}

descriptor_tag – This 8-bit field is set to 0xAD.

– This 8-bit field specifies the number of bytes of the descriptor immediately
descriptor_length
following the descriptor_length field.

– The format_identifier is a 32-bit field as defined in ISO/IEC 13818-1 [8], section

format_identifier
2.6.8 and 2.6.9 for the registration_descriptor(). Only format_identifier values registered and recognized by
the SMPTE Registration Authority, LLC shall be used (see http://www.smpte-ra.org/mpegreg.html). Its
use in this descriptor shall scope and identify only the private information contained within this
descriptor.

private_data_byte – The syntax and semantics of this field is defined by the assignee of the
format_identifier value.

5.8.3.9 Other A/65A descriptors

Inclusion in the Transport Stream of descriptors defined in ATSC A/65A [4] shall
conform to the requirements specified in [4] for table sections carried on cable.

5.8.4 PID Assignments

The following table defines PID assignments. Values not indicated in the table are
managed within the ATSC Code Point Registry.

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 Table 5.7 PID Assignment
PID Range Description
0x0000 ISO/IEC 13818-1 Program Association Table
0x0001 ISO/IEC 13818-1 Conditional Access Table
0x0002 ISO/IEC 13818-1 Transport Stream Description Table
0x0003-0x000F ISO/IEC 13818-1 Reserved
0x0010-0x001F Used by other International standards (DVB)
0x0020-0x002F Used by other International standards (ARIB)
0x0030-0x1FEF May be used for elementary streams, private data, or Program
Map Table data
0x1FFB PSIP and EA data (Ref. [4] and [5])
0x1FFE Reserved for DOCSIS
0x1FFF ISO/IEC 13818-1 Null packet

PID values used to identify Transport Stream packets carrying TS_program_map_section() or

program elements shall not be set less than 0x0010 or greater than 0x1FEF.
Beginning not later that January 1, 2006, in order to avoid collisions with fixed PID
values and ranges already established in this and other international standard, PID values used to
identify Transport Stream packets carrying TS_program_map_section() or program elements shall not
be set below 0x0030.

5.9 Extensions to the MPEG-2 Systems specification

This Section covers extensions to the MPEG-2 Systems specification.

5.9.1 Scrambling control

The scrambling control field within the TS packet header allows all states to exist in the
digital television system as defined in Table 5.8.

Table 5.8 Transport Scrambling Control Field

transport_
scrambling_ Function
control
00 packet payload not scrambled
01 not scrambled, state may be used as a flag for private use defined by the service provider.
10 packet payload scrambled with “even” key
11 packet payload scrambled with “odd” key

Elementary Streams for which the transport_scrambling_control field does not exclusively have
the value of ‘00’ for the duration of the program, shall carry a CA_descriptor in accordance with
Section 2.6.16 of ISO/IEC 13818-1.

5.10 Service Acquisition Considerations (Informative)

The ISO/IEC 13818-1 (MPEG-2 Systems) [8] and 13818-2 (MPEG-2 Video) standards
specify minimum rates for inclusion of PTS indicators in the bit stream (at least every 700

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milliseconds). These standards also require inclusion of a video sequence_header just once per
sequence, where a sequence could be several hours long. Service providers may (and often will)
choose rates for delivery of data critical to fast acquisition of the service that exceed the
minimum rates mandated by MPEG.
Care in creation of the multiplex can optimize service acquisition time within the same
multiplex, acquisition time to a new multiplex, acquisition of scrambled services, changes
between film and video modes (both directions), and change from video to still pictures mode.
Service providers may choose to send PTS values more often, such as once per picture. They
may repeat sequence_header information frequently, for example once every 0.5 seconds, and for
scrambled services, repeat relevant ECMs at a similar rate. These provisions can result in
improved acquisition performance at the expense incurring a small increase in bandwidth usage.

6. FEATURES OF ISO/IEC 13818-1 NOT SUPPORTED BY THIS STANDARD

The transport definition is based on the MPEG-2 Systems standard, ISO/IEC 13818-1;
however, it does not implement all parts of the standard. This Section describes those elements
which are omitted from this Standard.

6.1 Program streams

This Standard does not include those portions of ISO/IEC 13818-1 [8] and Annex A of
ATSC Standard A/52A [2] which pertain exclusively to Program Stream specifications.

7. TRANSPORT ENCODER OUTPUT BIT RATES

Conceptually, the output from the transport subsystem is a continuous MPEG-2
Transport Stream as defined in this Standard at a constant rate of T64 Mbps when transmitted in
an 64 QAM system and T256 when transmitted in a 256 QAM system where:
T64 = 26.97035 Mbps
and
T256 = 38.81070 Mbps.

The symbol rates in Msymbols per second for the transmission subsystem (see Table 3 of
Ref. [1]) are:
S64 = 5.056941 Msps
and
S256 = 5.360537 Msps.

T64 and S64 are locked to each other in frequency. Also T256 and S256 are locked to each
other in frequency.
All Transport Streams conforming to this Standard shall conform to the ISO/IEC 13818-1
model.

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