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`12 Apr 95
`16 Sep 95
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`ATSC DIGITAL TELEVISION STANDARD
`
`ADVANCED TELEVISION SYSTEMS COMMITTEE
`James C. McKinney, Chairman
`Dr. Robert Hopkins, Executive Director
`
`IPR2016-01710
`UNIFIED EX1038
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`ATSC DIGITAL TELEVISION STANDARD
`Table of Contents
`
`LIST OF FIGURES
`
`LIST OF TABLES
`
`vi
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`vii
`
`FOREWORD................................ ................................ ................................ ................................ .............1
`
`1. SCOPE & DOCUMENTATION STRUCTURE................................ ................................ ........................ 1
`1.1 Scope
`1
`1.2 Documentation structure
`1
`
`2. REFERENCES................................ ................................ ................................ ................................ ......1
`
`3. DEFINITIONS................................ ................................ ................................ ................................ .......2
`3.1 Definitions
`2
`3.2 Compliance notation
`2
`3.3 Treatment of syntactic elements
`2
`3.4 Terms employed
`2
`3.5 Symbols, abbreviations, and mathematical operators
`9
`3.5.1 Introduction
`9
`3.5.2 Arithmetic operators
`10
`3.5.3 Logical operators
`10
`3.5.4 Relational operators
`11
`3.5.5 Bitwise operators
`11
`3.5.6 Assignment
`11
`3.5.7 Mnemonics
`11
`3.5.8 Constants
`11
`3.5.9 Method of describing bit stream syntax
`12
`3.5.9.1 Definition of bytealigned function
`13
`3.5.9.2 Definition of nextbits function
`13
`3.5.9.3 Definition of next_start_code function
`13
`4. BACKGROUND................................ ................................ ................................ ................................ ..13
`4.1 Advanced Television Systems Committee (ATSC)
`13
`4.2 Advisory Committee on Advanced Television Service (ACATS)
`14
`4.3 Digital HDTV Grand Alliance (Grand Alliance)
`15
`4.4 Organization for documenting the Digital Television Standard
`15
`4.5 Principles for documenting the Digital Television Standard
`16
`
`5. SYSTEM OVERVIEW................................ ................................ ................................ .......................... 17
`5.1 Objectives
`17
`5.2 System block diagram
`18
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`ANNEX A - VIDEO SYSTEMS CHARACTERISTICS (Normative) ................................ .......................... 21
`
`1. SCOPE................................ ................................ ................................ ................................ ............... 21
`
`2. REFERENCES................................ ................................ ................................ ................................ ....21
`2.1 Normative references
`21
`2.2 Informative references
`21
`
`3. COMPLIANCE NOTATION................................ ................................ ................................ ................. 21
`
`4. POSSIBLE VIDEO INPUTS................................ ................................ ................................ ................. 21
`
`5. SOURCE CODING SPECIFICATION................................ ................................ ................................ ..22
`5.1 Constraints with respect to ISO/IEC 13818-2 Main Profile
`22
`5.1.1 Sequence header constraints
`22
`5.1.2 Compression format constraints
`23
`5.1.3 Sequence extension constraints
`23
`5.1.4 Sequence display extension constraints
`24
`5.1.5 Picture header constraints
`24
`5.2 Bit stream specifications beyond MPEG-2
`24
`5.2.1 Picture extension and user data syntax
`24
`5.2.2 Picture user data syntax
`25
`5.2.3 Picture user data semantics
`25
`
`ANNEX B - AUDIO SYSTEMS CHARACTERISTICS (Normative)................................ .......................... 27
`
`1. SCOPE................................ ................................ ................................ ................................ ............... 27
`
`2. NORMATIVE REFERENCES................................ ................................ ................................ ..............27
`
`3. COMPLIANCE NOTATION................................ ................................ ................................ ................. 27
`
`4. SYSTEM OVERVIEW................................ ................................ ................................ .......................... 27
`
`5. SPECIFICATION................................ ................................ ................................ ................................ .28
`5.1 Constraints with respect to ATSC Standard A/52
`28
`5.2 Sampling frequency
`29
`5.3 Bit rate
`29
`5.4 Audio coding modes
`29
`5.5 Dialogue level
`29
`5.6 Dynamic range compression
`29
`
`6. MAIN AND ASSOCIATED SERVICES................................ ................................ ................................ 30
`6.1 Overview
`30
`6.2 Summary of service types
`30
`6.3 Complete main audio service (CM)
`30
`6.4 Main audio service, music and effects (ME)
`31
`6.5 Visually impaired (VI)
`31
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`6.6 Hearing impaired (HI)
`6.7 Dialogue (D)
`6.8 Commentary (C)
`6.9 Emergency (E)
`6.10 Voice-over (V0)
`
`31
`32
`32
`32
`33
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`7. AUDIO ENCODER INTERFACES................................ ................................ ................................ .......33
`7.1 Audio encoder input characteristics
`33
`7.2 Audio encoder output characteristics
`33
`
`
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`ANNEX C - SERVICE MULTIPLEX AND TRANSPORT SYSTEMS CHARACTERISTICS (Normative)...34
`
`1. SCOPE................................ ................................ ................................ ................................ ............... 34
`
`2. NORMATIVE REFERENCES................................ ................................ ................................ ..............34
`
`3. COMPLIANCE NOTATION................................ ................................ ................................ ................. 34
`
`4. SYSTEM OVERVIEW................................ ................................ ................................ .......................... 34
`
`5. SPECIFICATION................................ ................................ ................................ ................................ .36
`5.1 MPEG-2 Systems standard
`36
`5.1.1 Video T-STD
`36
`5.1.2 Audio T-STD
`36
`5.2 Registration descriptor
`36
`5.2.1 Program identifier
`36
`5.2.2 Audio elementary stream identifier
`36
`5.3 The program paradigm
`37
`5.4 Constraints on PSI
`37
`5.5 PES constraints
`38
`5.5.1 Video PES constraints
`39
`5.5.2 Audio PES constraints
`39
`5.6 Services and features
`39
`5.6.1 Program guide
`39
`5.6.1.1 Master program guide PID
`39
`5.6.1.2 Program guide STD model
`40
`5.6.2 System information
`40
`5.6.2.1 System information PID
`40
`5.6.2.2 System information STD model
`40
`5.6.3 Specification of private data services
`41
`5.6.3.1 Verification model
`41
`5.6.3.1.1 Syntax and semantics
`41
`5.6.3.1.2 Ancillary service target decoder (ASTD)
`41
`5.6.3.2 Stream type and PMT descriptors
`41
`5.6.3.2.1 Stream type
`42
`5.6.3.2.2 PMT descriptors
`42
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`42
`5.7 Assignment of identifiers
`42
`5.7.1 Stream type
`43
`5.7.2 Descriptors
`43
`5.7.2.1 AC-3 audio descriptor
`43
`5.7.2.2 Program smoothing buffer descriptor.
`43
`5.8 Extensions to the MPEG-2 Systems specification
`43
`5.8.1 Scrambling control
`6. FEATURES OF 13818-1 NOT SUPPORTED BY THIS STANDARD................................ .................... 44
`6.1 Program streams
`44
`6.2 Still pictures
`44
`
`7. TRANSPORT ENCODER INTERFACES AND BIT RATES................................ ................................ ..44
`7.1 Transport encoder input characteristics
`44
`7.2 Transport output characteristics
`44
`
`
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`ANNEX D - RF/TRANSMISSION SYSTEMS CHARACTERISTICS (Normative)................................ .....46
`
`1. SCOPE................................ ................................ ................................ ................................ ............... 46
`
`2. NORMATIVE REFERENCES................................ ................................ ................................ ..............46
`
`3. COMPLIANCE NOTATION................................ ................................ ................................ ................. 46
`
`4. TRANSMISSION CHARACTERISTICS FOR TERRESTRIAL BROADCAST................................ .......46
`4.1 Overview
`46
`4.2 Channel error protection and synchronization
`48
`4.2.1 Prioritization
`48
`4.2.2 Data randomizer
`48
`4.2.3 Reed-Solomon encoder
`49
`4.2.4 Interleaving
`49
`4.2.5 Trellis coding
`50
`4.2.6 Data segment sync
`54
`4.2.7 Data field sync
`54
`4.2.7.1 Sync
`55
`4.2.7.2 PN511
`55
`4.2.7.3 PN63
`55
`4.2.7.4 VSB mode
`56
`4.2.7.5 Reserved
`56
`4.2.7.6 Precode
`57
`4.3 Modulation
`57
`4.3.1 Bit-to-symbol mapping
`57
`4.3.2 Pilot addition
`57
`4.3.3 8 VSB modulation method
`57
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`5. TRANSMISSION CHARACTERISTICS FOR HIGH DATA RATE MODE................................ .............57
`5.1 Overview
`57
`5.2 Channel error protection and synchronization
`59
`5.2.1 Prioritization
`59
`5.2.2 Data randomizer
`59
`5.2.3 Reed-Solomon encoder
`59
`5.2.4 Interleaving
`59
`5.2.5 Data segment sync
`60
`5.2.6 Data field sync
`60
`5.3 Modulation
`60
`5.3.1 Bit-to-symbol mapping
`60
`5.3.2 Pilot addition
`60
`5.3.3 16 VSB modulation method
`60
`
`ANNEX E - RECEIVER CHARACTERISTICS (INFORMATIVE)................................ ............................... 61
`
`1. SCOPE................................ ................................ ................................ ................................ ............... 61
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`2. REFERENCES TO EXISTING OR EMERGING STANDARDS................................ ............................. 61
`
`3. COMPLIANCE NOTATION................................ ................................ ................................ ................. 61
`
`4. STATUS OF RECEIVER STANDARDIZATION ACTIVITIES................................ ................................ 62
`4.1 Tuner performance
`62
`4.1.1 Noise figure
`62
`4.1.2 Channelization plan for broadcast and cable
`62
`4.1.3 Direct pickup
`62
`4.2 Transport
`62
`4.3 Decoder interface
`62
`4.4 Digital data interface
`62
`4.5 Conditional access interface
`63
`4.6 Closed captioning
`63
`
`5. RECEIVER FUNCTIONALITY................................ ................................ ................................ .............63
`5.1 Video
`63
`5.2 Audio
`63
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`List of Figures
`
`Figure 5.1. ITU-R digital terrestrial television broadcasting model.
`Figure 5.2. High level view of encoding equipment.
`
`ANNEX A
`None
`
`ANNEX B
`Figure 1. Audio subsystem in the digital television system.
`
`ANNEX C
`Figure 1. Sample organization of functionality in a transmitter-receiver pair for a single
`program.
`Figure 2. Ancillary service target decoder.
`
`ANNEX D
`Figure 1. VSB transmitter.
`Figure 2. VSB data frame.
`Figure 3. VSB channel occupancy (nominal).
`Figure 4. Randomizer polynomial.
`Figure 5. Reed-Solomon (207,187) t=10 parity generator polynomial.
`Figure 6. Convolutional interleaver (byte shift register illustration).
`Figure 7. 8 VSB trellis encoder, precoder, and symbol mapper.
`Figure 8. Trellis code interleaver.
`Figure 9. 8 VSB data segment.
`Figure 10. VSB data field sync.
`Figure 11. Field sync PN sequence generators.
`Figure 12. Nominal VSB system channel response (linear phase raised cosine Nyquist
`filter).
`Figure 13. 16 VSB data segment.
`Figure 14. 16 VSB transmitter.
`Figure 15. 16 VSB mapper.
`
`18
`19
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`28
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`35
`42
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`47
`47
`48
`49
`50
`50
`51
`52
`54
`55
`56
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`58
`59
`59
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`ANNEX E
`None
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`List of Tables
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`Table 3.1 Next Start Code
`
`ANNEX A
`Table 1 Standardized Video Input Formats
`Table 2 Sequence Header Constraints
`Table 3 Compression Format Constraints
`Table 4 Sequence Extension Constraints
`Table 5 Sequence Display Extension Constraints
`Table 6 Picture Extension and User Data Syntax
`Table 7 Picture User Data Syntax
`
`ANNEX B
`Table 1 Audio Constraints
`Table 2 Audio Service Types
`
`ANNEX C
`Table 1 PID Assignment for the Constituent Elementary Streams of a Program
`Table 2 Transport Scrambling Control Field
`
`ANNEX D
`Table 1 Interleaving Sequence
`Table 2 Byte to Symbol Conversion, Multiplexing of Trellis Encoders
`
`ANNEX E
`None
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`13
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`22
`22
`23
`23
`24
`24
`25
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`28
`30
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`37
`43
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`ATSC DIGITAL TELEVISION STANDARD
`
`FOREWORD
`This Standard was prepared by the Advanced Television Systems Committee (ATSC)
`Technology Group on Distribution (T3). The document was approved by the members of T3
`on February 23, 1995 for submission by letter ballot to the membership of the full ATSC as an
`ATSC Standard. The document was approved by the Members of the ATSC on April 12,
`1995. Changes to Annex A, to include standard definition video formats, were approved by the
`members of T3 on August 4, 1995 and by the Members of the ATSC on September 15, 1995.
`This Standard consists of a cover document which provides background information
`and an overview of the digital television system defined by the Standard. The system consists of
`various subsystems that are described in the annexes.
`
`1. SCOPE & DOCUMENTATION STRUCTURE
`
`1.1 Scope
`The Digital Television Standard describes the system characteristics of the U. S.
`advanced television (ATV) system. The document and its normative annexes provide detailed
`specification of the parameters of the system including the video encoder input scanning
`formats and the pre-processing and compression parameters of the video encoder, the audio
`encoder input signal format and the pre-processing and compression parameters of the audio
`encoder, the service multiplex and transport layer characteristics and normative specifications,
`and the VSB RF/Transmission subsystem.
`
`1.2 Documentation structure
`The documentation of the Digital Television Standard consists of this document which
`provides a general system overview, a list of reference documents, and sections relating to the
`system as a whole. The system is modular in concept and the specifications for each of the
`modules are provided in the appropriate annex.
`
`2. REFERENCES
`Normative references may be found in each normative Annex. The Digital Television
`Standard is based on the ISO/IEC MPEG-2 Video Standard, the Digital Audio Compression
`(AC-3) Standard, and the ISO/IEC MPEG-2 Systems Standard. Those references are listed
`
`NOTE: The user’s attention is called to the possibility that compliance with this standard may require use
`of an invention covered by patent rights. By publication of this standard, no position is taken with respect
`to the validity of this claim, or of any patent rights in connection therewith. The patent holder has,
`however, filed a statement of willingness to grant a license under these rights on reasonable and
`nondiscriminatory terms and conditions to applicants desiring to obtain such a license. Details may be
`obtained from the publisher.
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`here for the convenience of the reader. In addition, a guide to the use of the Digital Television
`Standard is listed.
`ATSC Standard A/52 (1995), Digital Audio Compression (AC-3).
`ATSC Document A/54 (1995), Guide to the Use of the ATSC Digital Television Standard.
`ISO/IEC IS 13818-1, International Standard (1994), MPEG-2 Systems.
`ISO/IEC IS 13818-2, International Standard (1994), MPEG-2 Video.
`
`3. DEFINITIONS
`
`3.1 Definitions
`With respect to definition of terms, abbreviations and units, the practice of the Institute
`of Electrical and Electronics Engineers (IEEE) as outlined in the Institute’s published standards
`shall be used. Where an abbreviation is not covered by IEEE practice, or industry practice
`differs from IEEE practice, then the abbreviation in question will be described in Section 3.4 of
`this document. Many of the definitions included therein are derived from definitions adopted by
`MPEG.
`
`3.2 Compliance notation
`As used in this document, “shall” or “will” 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 implementor.
`
`3.3 Treatment of syntactic elements
`This document contains symbolic references to syntactic elements used in the
`audio, video, and transport coding subsystems. These references are typographically
`distinguished by the use of a different font (e.g., restricted), may contain the underscore
`character (e.g., sequence_end_code) and may consist of character strings that are not English
`words (e.g., dynrng).
`
`3.4 Terms employed
`For the purposes of the Digital Television Standard, the following definition of
`terms apply:
`ACATS: Advisory Committee on Advanced Television Service.
`access unit: A coded representation of a presentation unit. In the case of audio, an access
`unit is the coded representation of an audio frame. In the case of video, an access unit
`includes all the coded data for a picture, and any stuffing that follows it, up to but not
`including the start of the next access unit. If a picture is not preceded by a group_start_code
`or a sequence_header_code, the access unit begins with a the picture start code. If a picture
`is preceded by a group_start_code and/or a sequence_header_code, the access unit begins with
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`the first byte of the first of these start codes. If it is the last picture preceding a
`sequence_end_code in the bit stream all bytes between the last byte of the coded picture and
`the sequence_end_code (including the sequence_end_code) belong to the access unit.
`A/D: Analog to digital converter.
`AES: Audio Engineering Society.
`anchor frame: A video frame that is used for prediction. I-frames and P-frames are
`generally used as anchor frames, but B-frames are never anchor frames.
`ANSI: American National Standards Institute.
`Asynchronous Transfer Mode (ATM): A digital signal protocol for efficient transport
`of both constant-rate and bursty information in broadband digital networks. The ATM
`digital stream consists of fixed-length packets called “cells,” each containing 53 8-bit
`bytes—a 5-byte header and a 48-byte information payload.
`ATEL: Advanced Television Evaluation Laboratory.
`ATM: See asynchronous transfer mode.
`ATTC: Advanced Television Test Center.
`ATV: The U. S. advanced television system.
`bidirectional pictures or B-pictures or B-frames: Pictures that use both future and past
`pictures as a reference. This technique is termed bidirectional prediction. B-pictures
`provide the most compression. B-pictures do not propagate coding errors as they are
`never used as a reference.
`bit rate: The rate at which the compressed bit stream is delivered from the channel to the
`input of a decoder.
`block: A block is an 8-by-8 array of pel values or DCT coefficients representing
`luminance or chrominance information.
`bps: Bits per second.
`byte-aligned: A bit in a coded bit stream is byte-aligned if its position is a multiple of 8-
`bits from the first bit in the stream.
`CDTV: See conventional definition television.
`channel: A digital medium that stores or transports a digital television stream.
`coded representation: A data element as represented in its encoded form.
`compression: Reduction in the number of bits used to represent an item of data.
`constant bit rate: Operation where the bit rate is constant from start to finish of the
`compressed bit stream.
`conventional definition television (CDTV): This term is used to signify the analog
`NTSC television system as defined in ITU-R Recommendation 470. See also standard
`definition television and ITU-R Recommendation 1125.
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`CRC: The cyclic redundancy check to verify the correctness of the data.
`D-frame: Frame coded according to an MPEG-1 mode which uses DC coefficients only.
`data element: An item of data as represented before encoding and after decoding.
`DCT: See discrete cosine transform.
`decoded stream: The decoded reconstruction of a compressed bit stream.
`decoder: An embodiment of a decoding process.
`decoding (process): The process defined in the Digital Television Standard that reads an
`input coded bit stream and outputs decoded pictures or audio samples.
`decoding time-stamp (DTS): A field that may be present in a PES packet header that
`indicates the time that an access unit is decoded in the system target decoder.
`digital storage media (DSM): A digital storage or transmission device or system.
`discrete cosine transform: A mathematical transform that can be perfectly undone and
`which is useful in image compression.
`DSM-CC: Digital storage media command and control.
`DSM: Digital storage media.
`DTS: See decoding time-stamp.
`DVCR: Digital video cassette recorder
`ECM: See entitlement control message.
`editing: A process by which one or more compressed bit streams are manipulated to
`produce a new compressed bit stream. Conforming edited bit streams are understood to
`meet the requirements defined in the Digital Television Standard.
`elementary stream (ES): A generic term for one of the coded video, coded audio or
`other coded bit streams. One elementary stream is carried in a sequence of PES packets
`with one and only one stream_id.
`elementary stream clock reference (ESCR): A time stamp in the PES Stream from
`which decoders of PES streams may derive timing.
`EMM: See entitlement management message.
`encoder: An embodiment of an encoding process.
`encoding (process): A process that reads a stream of input pictures or audio samples and
`produces a valid coded bit stream as defined in the Digital Television Standard.
`entitlement control message (ECM): Entitlement control messages are private
`conditional access information which specify control words and possibly other stream-
`specific, scrambling, and/or control parameters.
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`entitlement management message (EMM): Entitlement management messages are
`private conditional access information which specify the authorization level or the services
`of specific decoders. They may be addressed to single decoders or groups of decoders.
`entropy coding: Variable length lossless coding of the digital representation of a signal to
`reduce redundancy.
`entry point: Refers to a point in a coded bit stream after which a decoder can become
`properly initialized and commence syntactically correct decoding. The first transmitted
`picture after an entry point is either an I-picture or a P-picture. If the first transmitted
`picture is not an I-picture, the decoder may produce one or more pictures during
`acquisition.
`ES: See elementary stream.
`ESCR: See elementary stream clock reference.
`event: An event is defined as a collection of elementary streams with a common time base,
`an associated start time, and an associated end time.
`field: For an interlaced video signal, a “field” is the assembly of alternate lines of a frame.
`Therefore, an interlaced frame is composed of two fields, a top field and a bottom field.
`forbidden: This term, when used in clauses defining the coded bit stream, indicates that
`the value shall never be used. This is usually to avoid emulation of start codes.
`FPLL: Frequency and phase locked loop.
`frame: A frame contains lines of spatial information of a video signal. For progressive
`video, these lines contain samples starting from one time instant and continuing through
`successive lines to the bottom of the frame. For interlaced video a frame consists of two
`fields, a top field and a bottom field. One of these fields will commence one field later than
`the other.
`GOP: See group of pictures.
`Group of pictures (GOP): A group of pictures consists of one or more pictures in
`sequence.
`HDTV: See high definition television.
`high definition television (HDTV): High definition television has a resolution of
`approximately twice that of conventional television in both the horizontal (H) and vertical
`(V) dimensions and a picture aspect ratio (HxV) of 16:9. ITU-R Recommendation 1125
`further defines “HDTV quality” as the delivery of a television picture which is subjectively
`identical with the interlaced HDTV studio standard.
`high level: A range of allowed picture parameters defined by the MPEG-2 video coding
`specification which corresponds to high definition television.
`Huffman coding: A type of source coding that uses codes of different lengths to
`represent symbols which have unequal likelihood of occurrence.
`IEC: International Electrotechnical Commission.
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`intra-coded pictures or I-pictures or I-frames: Pictures that are coded using
`information present only in the picture itself and not depending on information from other
`pictures. I-pictures provide a mechanism for random access into the compressed video
`data. I-pictures employ transform coding of the pel blocks and provide only moderate
`compression.
`ISO: International Organization for Standardization.
`ITU: International Telecommunication Union.
`JEC: Joint Engineering Committee of EIA and NCTA.
`layer: One of the levels in the data hierarchy of the video and system specification.
`level: A range of allowed picture parameters and combinations of picture parameters.
`macroblock: In the advanced television system a macroblock consists of four blocks of
`luminance and one each Cr and Cb block.
`main level: A range of allowed picture parameters defined by the MPEG-2 video coding
`specification with maximum resolution equivalent to ITU-R Recommendation 601.
`main profile: A subset of the syntax of the MPEG-2 video coding specification that is
`expected to be supported over a large range of applications.
`Mbps: 1,000,000 bits per second.
`motion vector: A pair of numbers which represent the vertical and horizontal
`displacement of a region of a reference picture for prediction.
`MP@HL: Main profile at high level.
`MP@ML: Main profile at main level.
`MPEG: Refers to standards developed by the ISO/IEC JTC1/SC29 WG11, Moving
`Picture Experts Group. MPEG may also refer to the Group.
`MPEG-1: Refers to ISO/IEC standards 11172-1 (Systems), 11172-2 (Video), 11172-3
`(Audio), 11172-4 (Compliance Testing), and 11172-5 (Technical Report).
`MPEG-2: Refers to ISO/IEC standards 13818-1 (Systems), 13818-2 (Video), 13818-3
`(Audio), 13818-4 (Compliance).
`pack: A pack consists of a pack header followed by zero or more packets. It is a layer in
`the system coding syntax.
`packet data: Contiguous bytes of data from an elementary data stream present in the
`packet.
`packet identifier (PID): A unique integer value used to associate elementary streams of a
`program in a single or multi-program transport stream.
`packet: A packet consists of a header followed by a number of contiguous bytes from an
`elementary data stream. It is a layer in the system coding syntax.
`
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`

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`ATSC
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`Digital Television Standard
`
`16 Sep 95
`
`padding: A method to adjust the average length of an audio frame in time to the duration
`of the corresponding PCM samples, by continuously adding a slot to the audio frame.
`payload: Payload refers to the bytes which follow the header byte in a packet. For
`example, the payload of a transport stream packet includes the PES_packet_header and its
`PES_packet_data_bytes or pointer_field and PSI sections, or private data. A PES_packet_payload,
`however, consists only of PES_packet_data_bytes. The transport stream packet header and
`adaptation fields are not payload.
`PCR: See program clock reference.
`pel: See pixel.
`PES packet header: The leading fields in a PES packet up to but not including the
`PES_packet_data_byte fields where the stream is not a padding stream. In the case of a
`padding stream, the PES packet header is defined as the leading fields in a PES packet up
`to but not including the padding_byte fields.
`PES packet: The data structure used to carry elementary stream data. It consists of a
`packet header followed by PES packet payload.
`PES Stream: A PES stream consists of PES packets, all of whose payloads consist of data
`from a single elementary stream, and all of which have the same stream_id.
`PES: An abbreviation for packetized elementary stream.
`picture: Source, coded or reconstructed image data. A source or reconstructed picture
`consists of three rectangular matrices representing the luminance and two chrominance
`signals.
`PID: See packet identifier.
`pixel: “Picture element” or “pel.” A pixel is a digital sample of the color intensity values
`of a picture at a single point.
`predicted pictures or P-pictures or P-frames: Pictures that are coded with respect to
`the nearest previous I or P-picture. This technique is termed forward prediction.
`P-pictures provide more compression than I-pictures and serve as a reference for future
`P-pictures or B-pictures. P-pictures can propagate coding errors when P-pictures (or
`B-pictures) are predicted from prior P-pictures where the prediction is flawed.
`presentation time-stamp (PTS): A field that may be present in a PES packet header that
`indicates the time that a presentation unit is presented in the system target decoder.
`presentation unit (PU): A decoded audio access unit or a decoded picture.
`profile: A defined subset of the syntax specified in the MPEG-2 video coding
`specification
`program clock reference (PCR): A time stamp in the transport stream from which
`decoder timing is derived.
`program element: A generic term for one of the elementary streams or other data
`streams that may be included in the program.
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`ATSC
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`Digital Television Standard
`
`16 Sep 95
`
`program specific information (PSI): PSI consists of normative data which is necessary
`for the demultiplexing of transport streams and the successful regeneration of programs.
`program: A program is a collection of program elements. Program elements may be
`elementary streams. Program elements need not have any defined time base; those that do
`have a common time base and are intended for synchronized presentation.
`PSI: See program specific information.
`PTS: See presentation time-stamp.
`PU: See presentation unit.
`quantizer: A processing step which intentionally reduces the precision of DCT
`coefficients
`random access: The process of beginning to read and decode the coded bit stream at an
`arbitrary point.
`reserved: This term, when used in clauses defining the coded bit stream, indicates that the
`value may be used in the future for Digital Television Standard extensions. Unless
`otherwise specified within this Standard, all reserved bits shall be set to “1”.
`SCR: See system clock reference.
`scrambling: The alteration of the characteristics of a video, audio or coded data stream in
`order to prevent unauthorized reception of the information in a clear form. This alteration
`is a specified process under the control of a conditional access system.
`SDTV: See standard definition television.
`slice: A series of consecutive macroblocks.
`SMPTE: Society of Motion Picture and Television Engineers.
`source stream: A single, non-multiplexed stream of samples before compression coding.
`splicing: The concatenation performed on the system level or two different elementary
`streams. It is understood that the resulting stream must conform totally to the Digital
`Television Standard.
`standard definition television (SDTV): This term is used to signify a digital television
`system in which the quality is approximately equivalent to that of NTSC. This equivalent
`quality may be achieved from pictures sourced at the 4:2:2 level of ITU-R
`Recommendation 601 and subjected to processing as part of the bit rate compression. The
`results should be such that when judged across a representative sample of program
`material, subjective equivalence with NTSC is achieved. Also called standard digital
`television. See also conventional definition television and ITU-R Recommendation 1125.
`start codes: 32-bit codes embedded in the coded bit stream that are unique. They are used
`for several purposes including identifying some of the layers in the coding syntax. Start
`codes consist of a 24 bit prefix (0x000001) and an 8 bit stream_id.
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`— 8 —
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`

`
`ATSC
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`Digital Television Standard
`
`16 Sep 95
`
`STD input buffer: A first-in, first-out buffer at the input of a system target decoder for
`storage of compressed data from elementary streams before decoding.
`STD: See system target decoder.
`still picture: A coded still picture consists of a video sequence containing exactly one
`coded picture which is intra-coded. This picture has an associated PTS and the
`presentation time of succeeding pictures, if any, is later than that of the still picture by at
`least two picture periods.
`system clock reference (SCR): A time stamp in the program st