This file is raw output from pdftotext and may not be ideal for distribution. If you are a maintainer for Hackipedia, please sit down when you have time and clean this text version up. Source PDF: /mnt/fw-js/docs/ATSC/A-81 ATSC Direct-to-Home Satellite Broadcast Standard.pdf Like all conversions the text below should be fully readable as UTF-8 unicode text. --------------------------------------------------------------- Doc. A/81 30 July 2003 ATSC Direct-to-Home Satellite Broadcast Standard Advanced Television Systems Committee 1750 K Street, N.W. Suite 1200 Washington, D.C. 20006 www.atsc.org ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 The Advanced Television Systems Committee, Inc., is an international, non-profit organization developing voluntary standards for digital television. The ATSC member organizations represent the broadcast, broadcast equipment, motion picture, consumer electronics, computer, cable, satellite, and semiconductor industries. Specifically, ATSC is working to coordinate television standards among different communications media focusing on digital television, interactive systems, and broadband multimedia communications. ATSC is also developing digital television implementation strategies and presenting educational seminars on the ATSC standards. ATSC was formed in 1982 by the member organizations of the Joint Committee on InterSociety Coordination (JCIC): the Electronic Industries Association (EIA), the Institute of Electrical and Electronic Engineers (IEEE), the National Association of Broadcasters (NAB), the National Cable Television Association (NCTA), and the Society of Motion Picture and Television Engineers (SMPTE). Currently, there are approximately 140 members representing the broadcast, broadcast equipment, motion picture, consumer electronics, computer, cable, satellite, and semiconductor industries. ATSC Digital TV Standards include digital high definition television (HDTV), standard definition television (SDTV), data broadcasting, multichannel surround-sound audio, and satellite direct-to-home broadcasting. 2 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 Table of Contents 1. SCOPE .....................................................................................................................................................6 2. REFERENCES .........................................................................................................................................6 2.1 Normative references 6 2.2 Informative References 7 3. DEFINITIONS ...........................................................................................................................................7 3.1 Compliance Notation 7 3.2 Acronyms and Abbreviations 7 4. SYSTEM OVERVIEW...............................................................................................................................9 4.1 Transmission System 9 4.2 Integrated Receiver Decoder System 11 5. TRANSMISSION SUBSYSTEM .............................................................................................................11 6. TRANSPORT SUBSYSTEM SPECIFICATION......................................................................................11 6.1 Video T-STD 12 6.2 Audio T-STD 12 6.3 Identification of MPEG-2 Private Ranges 12 6.3.1 MPEG-2 Registration Descriptor 12 6.3.2 Program Identifier 12 6.3.3 Audio Elementary Stream Identifier 12 6.3.4 Other Program Element Identifiers 12 6.4 Constraints on PSI 13 6.5 PES Constraints 13 6.5.1 Audio PES Constraints 14 6.6 Specification of ATSC Private Data 14 6.7 Descriptors 14 6.7.1 Video Stream Descriptor 15 6.8 Audio Constraints 15 7. VIDEO SUBSYSTEM SPECIFICATION.................................................................................................15 7.1 Possible Video Inputs 15 7.2 Source Coding Specification 15 7.3 Constraints with Respect to ISO/IEC 13818-2 Main Profile 15 7.3.1 Sequence Header Constraints 16 7.3.2 Compression Format Constraints 16 7.3.3 Sequence Extension Constraints 17 7.3.4 Sequence Display Extension Constraints 18 7.3.5 Picture Coding Constraints 18 3 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 7.3.6 MPEG-2 Still Pictures 18 7.4 Bit Stream Specifications Beyond MPEG-2 19 7.4.1 Encoding and Transport of Advanced DTV Captions 19 7.4.2 Encoding and Transport of NTSC Closed Captions 19 7.4.3 Encoding of Other NTSC VBI Data 19 7.4.4 Encoding and Transport of Bar Data 19 7.4.5 Encoding and Transport of Active Format Description Data 19 8. AUDIO SUBSYSTEM SPECIFICATION ................................................................................................19 8.1 Constraints with Respect to ATSC Standard A/52A 19 8.1.1 Sampling Frequency 19 8.1.2 Audio Coding Modes 19 8.2 MPEG-1 Layer II Audio 20 9. PSIP SYSTEM ........................................................................................................................................20 9.1 Overview 20 9.2 Data Structure 21 9.2.1 Table Format 21 9.3 Extensibility 23 9.4 User Private Ranges 23 9.4.1 table_id values in the range 0x40 through 0xBF 23 9.5 Reserved Fields 23 9.6 Table Hierarchy and Structure Requirements 24 9.7 Requirements for Satellite Broadcast 25 9.8 Code points defined in this Standard 26 9.9 Specifications 26 9.9.1 Satellite Virtual Channel Table (SVCT) 26 9.9.2 Aggregate Event Information Tables (AEIT) 31 9.9.3 Aggregate Extended Text Tables (AETT) 34 9.9.4 Master Guide Table (MGT) 36 9.9.5 Core Descriptors 37 9.9.6 PSIP STD Model Constraints 37 10. CONDITIONAL ACCESS SUBSYSTEM ................................................................................................38 4 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 Tables and Figures Table 7.1 Standardized Video Input Formats 15 Table 7.2 Sequence Header Constraints 16 Table 7.3 Compression Format Constraints 17 Table 7.4 Sequence Extension Constraints 18 Table 7.5 Sequence Display Extension Constraints 18 Table 8.1 Audio Coding Mode 20 Table 9.1 Generic Table format used in Satellite PSIP 21 Table 9.2 Table ID Ranges and Values (Informative) 22 Table 9.3 Bit Stream Syntax for the Satellite Virtual Channel Table 27 Table 9.4 Modulation Modes 29 Table 9.5 Polarization Coding 30 Table 9.6 FEC_inner Coding 30 Table 9.7 Aggregate Event Information Table format 32 Table 9.8 Aggregate Extended Text Table Format 35 Table 9.9 ETM ID 36 Table 9.10 MGT Table Types for Satellite Application 36 Table 9.11 List of Descriptors for Satellite PSIP Tables 37 Table 9.12 Maximum cycle time for the STT, MGT, SVCT and RRT 38 Table 9.13 Maximum Rate for Each PSIP Packet Stream 38 Figure 4.1 Overview of the Transmission System. 10 Figure 4.2 Functional block diagram of an IRD system. 11 Figure 9.1 Table hierarchy for Satellite PSIP 24 5 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 ATSC Direct-to-Home Satellite Broadcast Standard 1. SCOPE This document describes the emission system for ATSC Direct-to-Home (DTH) Satellite Broadcast System. This specification defines extensions to audio, video, transport, and PSIP subsystems as defined in ATSC Standards A/53B and A/65A. The emission system defined in this document includes carriage of data broadcasting as defined in ATSC Standard A/90 without requiring extensions. Furthermore, transmission and conditional access subsystems are not defined, allowing service providers to use existing subsystems. 2. REFERENCES 2.1 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 20 2001: Standard Methods for Carriage of Closed Captions and Non-Real Time Sampled Video. 2. ANSI/SCTE 21 2001: Standard for Carriage of NTSC VBI Data in Cable Digital Transport Streams. 3. ATSC A/52A (2001): “Digital Audio Compression (AC-3).” 4. ATSC A/53B with Amendment 1: “ATSC Digital Television Standard.” 5. ATSC A/63 (1997): “Standard for Coding 25/50 Hz Video.” 6. ATSC A/65B (2003): “Program and System Information Protocol (PSIP) for Terrestrial Broadcast and Cable.” 7. ATSC A/80 (2000): “Modulation and Coding Requirements for Digital TV (DTV) Applications Over Satellite.” 8. ATSC T3-580 (2002): “Proposed Standard: Amendment 2 to A/53B.” 9. EIA/CEA-608-B (2000): Line 21 Data Services. 10. ANSI/SCTE 54 2002A: Digital Video Service Multiplex and Transport System Standard for Cable Television. 11. 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/65- A Program and System Information Protocol (PSIP). 12. EIA-708-B (1999): Digital Television (DTV) Closed Captioning. 13. EN 300 421 V1.1.2 (1997-08): “Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for 11/12 GHz satellite services.” 14. ISO 639.2 (1998): Code for the representation of names of languages Part 2: Alpha-3 code. 6 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 15. ISO/IEC 10646-1: 2000: Information technology—Universal Multiple-Octet Coded Character Set (UCS)—Part 1: Architecture and Basic Multilingual Plane. 16. ISO/IEC 13818-2: 2000/Cor. 1: 2001 (E) MPEG-2 Video Technical Corrigendum. 17. ISO/IEC IS 13818-1 (2000): Information Technology—Generic coding of moving pictures and associated audio—Part1: Systems. 18. ISO/IEC IS 13818-2 (2000): Information Technology—Generic coding of moving pictures and associated audio—Part 2: Video. 19. The Unicode Standard, Version 3.0, The Unicode Consortium, Addison-Wesley Pub., ISBN 0201616335. 2.2 Informative References 20. ANSI/SCTE 07 2000: Digital Video Transmission System Standard for Cable Television. 21. ANSI/SCTE 43 2002: Digital Video Systems Characteristics Standard for Cable Television. 22. ANSI/SCTE 65 2002: Service Information Delivered Out-of-Band for Digital Cable Television. 23. ATSC A/56 (1996): “System Information for Digital Television,” 24. ATSC A/70 (2000): “Conditional Access System for Terrestrial Broadcast.” 25. ATSC A/90 (2000): “Data Broadcast Standard.” 26. ETSI EN 300 468 V1.4.1 (2000-11): “Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB systems.” 27. ISO/IEC 8859, Information Processing—8-bit Single-Octet Coded Character Sets, Parts 1 through 10. 28. ISO/IEC IS 11172-3, International Standard (1993), MPEG-1 Audio. 29. ITU-R BT.601-5: Encoding parameters of digital television for studios. 30. ITU-R BT.709: Basic Parameter Values for the HDTV Standard for the Studio and for International Programme Exchange. 31. ITU-T J.83B: Digital Video Transmission Standard for Cable Television. 32. SMPTE 274M (1995): Standard for television, 1920 x 1080 Scanning and Interface. 33. SMPTE 296M (1997): Standard for television, 1280 x 720 Scanning, Analog and Digital Representation, and Analog Interface. 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, which may or may not be present at the option of the implementor. 3.2 Acronyms and Abbreviations The following acronyms and abbreviations are used within this specification: 7 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 AEIT aggregate event information table AETT aggregate extended text table ASTD ancillary service target decoder ATSC Advanced Television Systems Committee BPSK binary phase shift keying bslbf bit serial, leftmost bit first CA conditional access CAT conditional access table CRC cyclic redundancy check CVCT cable virtual channel table DET data event table 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 ETM extended text message ETT extended text table GPS Global Positioning System IEC International Electrotechnical Commission ISO International Organization for Standardization MGT master guide table MPEG Moving Picture Experts Group MRD MPEG registration descriptor PAT program association table PES packetized elementary stream PID packet identifier PMT program map table PSI program specific information PSIP Program and System Information Protocol PTS presentation time stamp OQPSK offset quadrature phase shift keying QAM quadrature amplitude modulation QPSK quadrature phase shift keying 8 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 rpchof remainder polynomial coefficients, highest order first RRT rating region table SCTE Society of Cable Telecommunications Engineers SI service information STD system target decoder STT system time table TS transport stream T-STD transport stream system target decoder TVCT terrestrial virtual channel table uimsbf unsigned integer, most significant bit first UTC coordinated universal time1 VBV video buffering verifier 4. SYSTEM OVERVIEW The Satellite Broadcast System comprises of two major subsystems: 1) the Transmission System and 2) an Integrated Receiver Decoder, commonly referred as a Set Top Box (STB). 4.1 Transmission System The transmission system comprises an Emission Mux, a Modulator/Encoder, and a Transmitter. The Emission Mux requirements are discussed in this document. Specifications for the Modulator/Encoder and the Transmitter were deemed not necessary for the purposes of this standard, and are left for Service Provider to develop. 1 Because unanimous agreement could not be achieved by the ITU on using either the English word order, CUT, or the French word order, TUC, a compromise to use neither was reached. 9 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 Note : These stream s delivered by ASI, G.703, ATM, 10BT/100BT A/81 Ethernet. Com pliant ATSC Com pliant Transport Modulator Multiprogram ASI Transport Stream Broadcast Network Em ission Mux ATSC Com pliant A/81 Multiprogram Com pliant Transport Stream Transport ASI Modulator Optional Transport Stream s PSIP with Satellite Extensions Data Figure 4.1 Overview of the Transmission System. Figure 4.1 shows a functional block diagram of a transmission system. The Emission Mux accepts and combines: • ATSC multi-program transport streams (A/53B, A/65B, A/70, and A/90 protocols) from different sources • Satellite extensions to PSIP Additionally, the Emission Mux may accept: • MPEG Compliant (non-ATSC) transport streams • Data streams such as A/90 and DVB data broadcast Each multi-program transport stream output from the Emission Mux to a modulator shall conform with: • Transport, audio, and video format extensions defined for satellite delivery in this standard. • System Information with all the normative elements from A/65B (PSIP) and Satellite extensions such as the Satellite VCT defined in this standard. Transport Streams at the output of the Emission Mux may also carry additional information to support delivery system specific needs (such as DVB-SI [26], A/56 [23], control data, EIA- 10 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 608B captions using ANSI/SCTE 20 2001 [1], and MPEG-1 Layer 2 audio [28]). When present, such information shall not conflict with the code points used in this standard. 4.2 Integrated Receiver Decoder System A functional block diagram of an Integrated Receiver Decoder (IRD) system is depicted in Figure 4.2. This system demodulates and decodes audio, video, and data streams compatible with the transmission system described in Section 4.1. Tuner Demod Demux Descrambler Video Audio Data Control CA PSIP Figure 4.2 Functional block diagram of an IRD system. 5. TRANSMISSION SUBSYSTEM This Standard does not specify the transmission element of the delivery system. Service providers may use existing or future delivery systems for transmission. However, the transport, video, audio, and PSIP must comply with the specifications given in the following sections. 6. TRANSPORT SUBSYSTEM SPECIFICATION This section constitutes the normative specification for the transport system of the Service Multiplex and Transport System Standard for the ATSC DTH Satellite Specification. The transport sub-system shall comply with the transport stream definition of the MPEG-2 Systems standard as specified in ISO/IEC 13818-1 and shall be further constrained as specified herein. 11 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 6.1 Video T-STD The video Transport Stream System Target Decoder (T-STD) shall comply with Section 2.4.2.3 of ISO/IEC 13818-1 and shall follow the constraints for the level encoded in the video elementary stream. 6.2 Audio T-STD The audio T-STD shall comply with section 3.6 of Annex A of ATSC standard A/52A. 6.3 Identification of MPEG-2 Private Ranges ATSC defines code points in the MPEG-2 user private range and may define code points private to ATSC users within this range. 6.3.1 MPEG-2 Registration Descriptor Under circumstances as defined Section 6.3.2 – 6.3.4, this Standard uses the MPEG-2 Registration Descriptor described in Section 2.6.8 and 2.6.9 of ISO/IEC 13818-1 [17] 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. 6.3.2 Program Identifier Programs which conform to this specification may be identified by the format identifier carried in the registration_descriptor in the Program Map Table (PMT) detailed in Section 2.4.4.8 of ISO/IEC 13818-1 [17]. The identifier shall be coded according to Section 2.6.8 and when present shall have a value of 0x5331 3441 (“S14A” in ASCII) for programs that comply to ATSC Satellite Broadcast. Optionally, some of the programs may carry the registration_descriptor with format_identifier values of 0x4741 3934 (“GA94” in ASCII) for programs that comply to ATSC terrestrial broadcast, 0x5343 5445 (“SCTE” in ASCII) for programs that comply with ANSI/SCTE 54 [10], and identifiers for programs that comply to DVB standards. The MRD containing one of these format identifiers shall only be present in the outer loop of the PMT and shall apply to all the elementary streams within the program. Only one registration_descriptor shall be present in the outer loop even though a mix of registration descriptors can occur within a multi-program transport stream. 6.3.3 Audio Elementary Stream Identifier Audio elementary streams that conform to ATSC standards may use an MPEG-2 Registration Descriptor (as defined in Section 2.6.8 and 2.6.9 of ISO/IEC 13818-1 [17]). When present, the 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 of stream_type 0x81 (AC-3 audio). The format_identifier field of the MPEG-2 Registration Descriptor shall have a value of 0x4143 2D33 (“AC-3” in ASCII). 6.3.4 Other Program Element Identifiers Any program element carrying content not described by an approved ATSC 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 [17]). The format_identifier field of the MPEG-2 Registration Descriptor shall be registered with the SMPTE Registration Authority, LLC. The descriptor shall be placed in the 12 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 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 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 ATSC-user private range, 0xC4 to 0xFF, to establish the private entity associated with that program element. 6.4 Constraints on PSI The program constituents for all programs are described in the PSI according to ISO/IEC 13818- 1 [17]. 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. • 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_indicator that the version_number (Section 2.4.4.5 of ISO/IEC 13818-1 [17]) 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 [17]) 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. 6.5 PES Constraints Packetized Elementary Stream syntax and semantics as defined in [17] shall be used to encapsulate the audio and video elementary stream information defined in this specification. The 13 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 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’. 6.5.1 Audio PES Constraints The audio decoder may be capable of simultaneously decoding more than one audio elementary stream. 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 (or block) basis. In order to have the audio from the two elementary streams reproduced in exact sample synchronism, it is necessary 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). 6.6 Specification of ATSC Private Data Private Data shall be transported in accordance with Annex C of A/53B [4, 8]. 6.7 Descriptors Coding and transport of the AC-3 Audio Descriptor, Program Smoothing Buffer Descriptor, ISO-639 Language Descriptor, and ATSC Private Information Descriptor shall be in accordance with Annex C of A/53B [4, 8]. 14 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 6.7.1 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 [17] in the TS_program_map_section describing that elementary stream. 6.8 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 [3], including all voice-overs and emergency messages, when these are present in the Transport Stream. 7. VIDEO SUBSYSTEM SPECIFICATION This section describes the characteristics and normative specifications for the Video Subsystem Standard for ATSC Satellite Broadcast system. 7.1 Possible Video Inputs While not required by this standard, there are certain television production standards, shown in Table 7.1, that define video formats that relate to compression formats specified by this standard. Table 7.1 Standardized Video Input Formats Video Standard Active Lines Active Samples/Line SMPTE 274M 1080 1920 SMPTE 296M 720 1280 ITU-R BT.601-5 483 720 The compression formats may be derived from one or more appropriate video input formats. It may be anticipated that additional video production standards will be developed in the future that extend the number of possible input formats. 7.2 Source Coding Specification The video compression algorithm shall conform to the Main Profile syntax of ISO/IEC 13818-2 (2000) including Technical Corrigendum 1 [16, 18]. The allowable parameters shall be bounded by the upper limits specified for the Main Profile at High Level.2 Additionally, bit streams shall meet the constraints and extensions described in Sections 7.3 and 7.4. 7.3 Constraints with Respect to ISO/IEC 13818-2 Main Profile The following tables list the allowed values for each of the ISO/IEC 13818-2 [16, 18] syntactic elements. These values constrain what is specified by MP@HL. In these tables conventional numbers denote decimal values, numbers preceded by 0x are to be interpreted as hexadecimal values and numbers within single quotes (e.g., ‘10010100’) are to be interpreted as a string of binary digits. 2 See ISO/IEC 13818-2, Section 8 for more information regarding profiles and levels. 15 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 7.3.1 Sequence Header Constraints Table 7.2 identifies parameters in the sequence header of a bit stream that shall be constrained by the video subsystem and lists the allowed values for each. Table 7.2 Sequence Header Constraints Sequence Header Syntactic Element Allowed Value horizontal_size_value See Table 7.3 vertical_size_value See Table 7.3 aspect_ratio_information See Table 7.3 frame_rate_code See Table 7.3 bit_rate_value ≤ 200,000 Vbv_buffer_size_value ≤ 488 The allowable values for the field bit_rate_value are application-dependent. The maximum limit is 80 Mbps for MPEG-2 MP@HL. 7.3.2 Compression Format Constraints The allowed compression formats shall be as listed in Table 7.3, and for 25/50 Hz video Table 3 in ATSC A/63 [5]. 16 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 Table 7.3 Compression Format Constraints vertical_size_ horizontal_size_ aspect_ratio_ frame_rate_ Progressive value value information code /Interlaced 1080 1280 3 1,2,4,5,7,8 P 1080 1280 3 4,5,7,8 I 1080 1920 1, 3 1, 2, 4, 5,7,8 P 1080 1920 1, 3 4, 5,7,8 I 1080 1440 3 1, 2, 4, 5,7,8 P 1080 1440 3 4, 5,7,8 I 720 1280 1, 3 1, 2, 4, 5, 7, 8 P 480 720 2, 3 1, 2, 4, 5, 7, 8 P 480 720 2, 3 4, 5 I 480 704 2, 3 1, 2, 4, 5, 7, 8 P 480 704 2, 3 4, 5 I 480 640 1, 2 1, 2, 4, 5, 7, 8 P 480 640 1, 2 4, 5 I 480 544 2 1 P 480 544 2 4 I 480 480 2 4,5 I 480 528 2 1 P 480 528 2 4 I 480 352 2 1 P 480 352 2 4 I Legend for MPEG-2 Coded Values aspect_ratio_information: 1 = square samples, 2 = 4:3 display aspect ratio, 3 = 16:9 display aspect ratio frame_rate_code: 1 = 23.976 Hz, 2 = 24 Hz, 4 = 29.97 Hz, 5 = 30 Hz, 7 = 59.94 Hz, 8 = 60 Hz Progressive/Interlace: I= interlaced scan, P = progressive scan 7.3.3 Sequence Extension Constraints A sequence_extension shall be present immediately after each sequence_header. The sequence_extension shall conform to the constraints listed in Table 7.4. 17 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 Table 7.4 Sequence Extension Constraints Sequence Extension Syntactic Element Allowed Values Progressive_sequence See Table 3 Profile_and_level_indication See Note chroma_format ‘01’ horizontal_size_extension ‘00’ vertical_size_extension ‘00’ bit_rate_extension ‘0000 0000 0000’ Vbv_buffer_size_extension ‘0000 0000’ Frame_rate_extension_n ‘00’ Frame_rate_extension_d ‘0000 0’ Note: The profile_and_level_indication field shall indicate the lowest profile and level defined in ISO/IEC 13818-2 [16, 18], Section 8, that is consistent with the parameters of the video elementary stream. 7.3.4 Sequence Display Extension Constraints Table 7.5 identifies parameters in the sequence display extension part of a bit stream that shall be constrained by the video subsystem and lists the allowed values for each. Table 7.5 Sequence Display Extension Constraints Sequence Display Extension Syntactic Element Allowed Values video_format ‘000’ The values for color_primaries, transfer_characteristics, and matrix_coefficients shall be explicitly indicated in the sequence_display_extension. While all values for color_primaries, transfer_characteristics, and matrix_coefficients defined in Tables 6-7, 6-8, and 6-9 of ISO/IEC 13818-2 [16, 18] are allowed in the transmitted bit stream, it is noted that ITU-R BT.709 [27] and SMPTE 170M are the most likely to be in common use. Note: Some previously-encoded legacy material may not have the colorimetry (i.e., color_primaries, transfer_characteristics, and matrix_coefficients) explicitly indicated in the sequence_display_extension, in which case the colorimetry is most likely ITU-R BT.709 for all formats except those formats with vertical_size_value = 480, which are most likely to have colorimetry according to SMPTE 170M. 7.3.5 Picture Coding Constraints frame_pred_frame_dct shall be ‘1’ if progressive_frame is ‘1’. 7.3.6 MPEG-2 Still Pictures Certain services may include video elementary streams conforming to the ISO/IEC 13818-1 [17] 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. 18 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 7.4 Bit Stream Specifications Beyond MPEG-2 This section covers the extension and user data part of the video syntax. These data are inserted at the sequence, GOP, and picture level and are used to carry advanced DTV closed captions, as well as NTSC closed captions and other data that might be present in the VBI of an NTSC signal. 7.4.1 Encoding and Transport of Advanced DTV Captions Advanced DTV closed captions, when present, shall be encoded in accordance with EIA-708-B [12] and shall be transported in accordance with ATSC A/53B [4, 8] (note that advanced DTV captions are signaled in A/53B by setting the cc_type field to ’10’ or ’11’). 7.4.2 Encoding and Transport of NTSC Closed Captions NTSC captions, when present, shall be encoded in accordance with EIA-608-B [9] and shall be transported in accordance with ATSC A/53B as modified by Amendment 1 [4, 8] (note that NTSC captions are signaled in A/53B by setting the cc_type field to '00' or '01'.). NTSC captions may also be dual carried using the video_user data mechanism as defined in ANSI/SCTE 20 [1]. 7.4.3 Encoding of Other NTSC VBI Data For transport of other NTSC VBI data, see [1] and [2]. 7.4.4 Encoding and Transport of Bar Data Bar data, when present, shall be encoded and transported in accordance with ATSC A/53B [4] as modified by Amendment 1 to ATSC A/53B [8]. 7.4.5 Encoding and Transport of Active Format Description Data Active format description data, when present, shall be encoded and transported in accordance with ATSC A/53B [4, 8] as modified by Amendment 1 to ATSC A/53B. 8. AUDIO SUBSYSTEM SPECIFICATION This section describes the characteristics and normative specifications for the Audio Subsystem Standard for ATSC Satellite Broadcast system. 8.1 Constraints with Respect to ATSC Standard A/52A Audio compression shall conform with the Digital Audio Compression (AC-3) Standard, ATSC A/52A [3], subject to the constraints defined in A/53B with Amendment 1, Annex B [4, 8], except for the sampling frequency stipulated in Section 8.1.1. 8.1.1 Sampling Frequency The sample rate shall be constrained to either 48 kHz or 44.1 kHz, corresponding to fscod values of ‘00’ (48 kHz) and ‘01’ (44.1 kHz), respectively. 8.1.2 Audio Coding Modes This 3-bit audio coding mode, acmod, in A/52A [3], specified in Table 8.1, indicates which of the main service channels are in use. Note: the dual mono mode, acmod = 0, is not allowed. 19 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 Table 8.1 Audio Coding Mode acmod Audio Coding Mode nfchans Channel Array Ordering ‘000’ Not allowed ‘001’ 1/0 1 C ‘010’ 2/0 2 L, R ‘011’ 3/0 3 L, C, R ‘100’ 2/1 3 L, R, S ‘101’ 3/1 4 L, C, R, S ‘110’ 2/2 4 L, R, SL, SR ‘111’ 3/2 5 L, C, R, SL, SR 8.2 MPEG-1 Layer II Audio MPEG-1 Layer II audio may be optionally carried within the same program. If present, this audio shall be signaled with stream_type value 0x03 in the Program Map Table. 9. PSIP SYSTEM This section defines an extension to the A/65 Program and System Information Protocol standard [6] for satellite broadcasting applications. The syntax and semantics of [6] shall be followed unless otherwise constrained herein. Digital multiplex bit streams conformant to this specification are constructed in accordance with ISO/IEC 13818-1 (MPEG-2 Systems) [17]. The document defines the standard protocol for transmission of the relevant data tables contained within packets carried in the Transport Stream multiplex. 9.1 Overview These sections describes tables that shall be applicable to satellite transmission systems. Some tables may be used in common with terrestrial broadcast and/or cable systems. The following tables shall be included in all ATSC-compliant Transport Streams to be transmitted via satellite broadcast: • The Satellite Virtual Channel Table (SVCT) defining, at a minimum, the virtual channel structure for the collection of MPEG-2 programs embedded in the Transport Stream in which the SVCT is carried. • The Master Guide Table (MGT) defining the type, packet identifiers, and versions for all of the other Satellite PSIP tables included in this Transport Stream, except for the System Time Table (STT). • The Rating Region Table (RRT) defining the TV parental guideline system referenced by any content advisory descriptor carried within the Transport Stream, except the RRT 3 corresponding to rating_region 0x01 (US + possessions). 3 Note: Interpretation in a receiver of the rating_region 0x01 RRT requires prior knowledge of EIA/CEA-766-A [11]; therefore transmission is unnecessary. A future extension or replacement of the content advisory system for the US is possible by assignment of a new, different rating_region code and creation of new content for an RRT. 20 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 • The System Time Table (STT), defining the current date and time of day and daylight savings time transition timing. • The first four Aggregate Event Information Tables (AEIT-0, AEIT-1, AEIT-2, and AEIT-3). 9.2 Data Structure This section describes the data structure common to all satellite PSIP tables. 9.2.1 Table Format Tables defined in this Standard are derived from the “long” form of the MPEG-2 private_section defined in sections 2.4.4.10 and 2.4.4.11 of ISO/IEC 13818-1 [17]. The table format common to all satellite PSIP tables is given in Table 9.1. An additional field, protocol_version, has been added immediately following the long-form header portion of the table section. Table 9.1 Generic Table format used in Satellite PSIP Syntax No. of Bits Format PSIP_section( ) { table_id 8 uimsbf section_syntax_indicator 1 ‘1’ private_indicator 1 ‘1’ reserved 2 ‘11’ section_length 12 uimsbf table_id_extension 16 uimsbf reserved 2 ‘11’ version_number 5 uimsbf current_next_indicator 1 bslbf section_number 8 uimsbf last_section_number 8 uimsbf protocol_version 8 uimsbf PSIP_table_data() * CRC_32 32 rpchof } table_id —The value of this 8-bit field identifies the table this section belongs to. Tables defined in this Standard, and any created as user extensions to it are considered “private” with respect to ISO/IEC 13818-1. Informative Table 9.2 lists Table ID ranges and values. 21 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 Table 9.2 Table ID Ranges and Values (Informative) Table ID Tables PID Reference Value (hex) ISO/IEC 13818-1 Sections 0x00 program association table (PAT) 0 [17] 0x01 conditional access table (CAT) 1 [17] 0x02 TS program map table (PMT) per PAT [17] 0x03 TS description table (TSDT) 2 [17] 0x04-0x3F ISO Reserved or ISO Assigned User Private Sections 0x40-0xBF User private PSIP Tables 0xC7 master guide table (MGT) 0x1FFB Section 9.11.4 0xCA rating region table (RRT) 0x1FFB [6] 0xCD system time table (STT) 0x1FFB [6] 0xD6 aggregate event information table (AEIT) per MGT Section 9.11.2 0xD7 aggregate extended text table (AETT) per MGT Section 9.11.3 0xDA satellite virtual channel table (SVCT) per MGT Section 9.11.1 section_syntax_indicator — This 1-bit field shall be set to ‘1’ to always indicate the “long” form of the MPEG-2 private_section table. private_indicator — This 1-bit field shall be set to ‘1’. private_section_length — A 12-bit field. It specifies the number of remaining bytes in the private section immediately following this field up to and including the CRC_32 field. The value in this field shall not exceed 4093 (0xFFD). table_id_extension — This is a 16-bit field and is table-dependent. It shall be considered to be logically part of the table_id field providing the scope for the remaining fields. version_number — This 5-bit field is the version number of the PSIP_section. The version_number shall be incremented by 1 modulo 32 when a change in the information carried within the PSIP_section occurs. When the current_next_indicator is set to '0', then the version_number shall be that of the next applicable PSIP_section() with the same table_id, table_id_extension, section_number, and protocol_version. When the current_next_indicator is set to '1', then the version_number shall be that of the current PSIP_section() with the same table_id, table_id_extension, section_number, and protocol_version. current_next_indicator — A 1-bit field, which when set to ‘1’ indicates that the PSIP_section sent is currently applicable. When the current_next_indicator is set to '1', then the version_number shall be that of the currently applicable PSIP_section. When the bit is set to ’0’, it indicates that the PSIP_section sent is not yet applicable and shall be the next PSIP_section with the same section_number, table_id_extension, and table_id to become valid. section_number — This 8-bit field gives the number of the PSIP_section. The section_number of the first section in a PSIP table shall be 0x00. The section_number shall be incremented by 1 with each additional section in PSIP table. The scope of the section_number shall be defined by the 22 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 table_id and table_id_extension. That is, for each PSIP table and value of the table_id_extension field, there is the potential for the full range of section_number values. last_section_number — This 8-bit field specifies the number of the last section (that is, the section with the highest section_number) of the PSIP table of which this section is a part. Its scope is the same as for the section_number field. protocol_version — An 8-bit unsigned integer field whose function is to allow, in the future, this table type to carry parameters that may be structured differently than those defined in the current protocol. At present, the only valid value for protocol_version is zero, but non-zero values may appear in the TS as the result of future standards activities. Non-zero values of protocol_version may be used by a future version of this standard to indicate structurally different tables. CRC_32 — This is a 32-bit field that contains the CRC value that gives a zero output of the registers in the decoder defined in ISO/IEC 13818-1 [17], Annex A after processing the entire private section. Note that individual PSIP tables defined in this Standard may further constrain the above fields. But when not further constrained in each table, the above semantics shall apply. 9.3 Extensibility The PSIP protocol describes a number of tables conveying system information and content guide data structures. The Standard is designed to be extensible via the following mechanisms: • Reserved fields: Fields in this Standard marked reserved shall be reserved for use either when revising this Standard, or when another standard is issued that builds upon this one. • Standard table types: An extension or update to this Standard can define a new table type with a table_id value assigned by the ATSC registrar. • Protocol Version Field: Initially this field is set to 0, but after approval, future structural modifications shall be accommodated by defining different protocol version numbers. 9.4 User Private Ranges Certain fields in this Standard are defined to include “user private” ranges. 9.4.1 table_id values in the range 0x40 through 0xBF Table sections with table_id values in the user private range (0x40 through 0xBF) shall not appear in transport packets identified with the satellite base_PID PID value (0x1FFB). The MGT may refer to private table sections with any value of table_id including values in the user private range. 9.5 Reserved Fields Fields in this Satellite PSIP Standard marked “reserved” shall not be assigned by the user, but shall be available for future use. Decoders are expected to disregard reserved fields for which no definition exists that is known to that unit. Each bit in the fields marked “reserved” shall be set to one until such time as they are defined and supported. 23 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 9.6 Table Hierarchy and Structure Requirements The Program and System Information Protocol for satellite applications is a collection of hierarchically arranged tables for describing system information and program guide data. These tables are packetized and multiplexed according to the transport protocol detailed in ISO/IEC 13818-1 [17]. The base PID (base_PID) is an explicitly defined value (0x1FFB) used to identify the packets for the following tables: The System Time Table (STT), the Master Guide Table (MGT), and the Rating Region Table (RRT). The MGT gives PID values used to transport sections of the Satellite Virtual Channel Tables (SVCT), Aggregate Event Information Tables (AEITs), and Aggregate Extended Text Tables (AETTs). Figure 9.1 illustrates the relations between these elements. Figure 9.1 Table hierarchy for Satellite PSIP In Figure 9.1, multiple SVCTs are transmitted, labeled SVCT-0 through SVCT-r where the number following the dash is given by the SVCT_id parameter. As shown, each is carried in TS packets identified with a different value of PID. There is no restriction on PID values that prevents SVCT-m from appearing in TS packets with the same PID value as SVCT-n for any values of m and n. The figure also shows that one or more AEIT instances can appear in TS packets with the same PID value as other AEIT instances. The same applies for AETT instances. PID assignment for any AEIT or AEIT (any time slot) is totally flexible and unconstrained. 24 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 As the name indicates, the System Time Table (STT) carries time information needed for any application requiring synchronization. The Rating Region Table (RRT) defines rating tables valid for different regions or countries. The Master Guide Table (MGT) defines sizes, PIDs, and version numbers for all of the relevant tables. The purpose of the Satellite Virtual Channel Table (SVCT) is to tabulate virtual channel attributes required for navigation and tuning. The SVCT is similar in structure to the Cable and Terrestrial VCTs defined in ATSC Standard A/65 [6]. In the satellite application, more than one different SVCT may be present in the same Transport Stream. Any given receiver can make use of one or more of the available SVCTs for tuning and navigation. The mechanism for selection of relevant SVCTs is outside the scope of this standard. Each of the Aggregate Event Information Tables (AEITs) lists TV programs (events) for the virtual channels described in the SVCT. The AEITs are organized from AEIT-0 to AEIT-255. The first table (AEIT-0) corresponds to the currently valid list of events. The second table (AEIT-1) corresponds to the next 3-hour time window, and so on. During remultiplexing, AEIT tables which originally existed in separate Transport Streams may be multiplexed into a common Transport Stream or vice versa. For this reason, it is very convenient to synchronize the start times and durations of the AEITs. Consequently, the following three synchronization rules shall be followed when AEIT tables are prepared. • Requirement 1: Each AEIT shall have a duration of 3 hours. • Requirement 2: Start times for AEITs are restricted to 0:00 (midnight), 3:00, 6:00, 9:00, 12:00 (noon), 15:00, 18:00, and 21:00. All of these times are UTC. • Requirement 3: AEIT-0 lists all of the available events for the current 3-hour time segment. AEIT-1 lists all of the available events for the next 3-hour time segment, and likewise, non-overlapping sequential time windows are allocated for all of the other AEITs. For example, a broadcast group operating in the Eastern time zone of the U.S. at 15:30 EDT (19:30 UTC) is required to carry AEIT-0 describing events from 14:00 to 17:00 EDT (18:00 to 21:00 in UTC time) plus AEIT-1, AEIT-2, and AEIT-3 covering the next 9-hour interval between 17:00 to 2:00 EDT. At 17:00 EDT, the first table, AEIT-0, will be obsolete while AEIT- 1 will still be valid. At this time, simply by shifting the listed PID values in the MGT, AEIT-1 becomes AEIT-0 and AEIT-2 becomes AEIT-1. Updating tables then becomes a process of shifting the list of PIDs in the MGT and their corresponding version numbers. However, updates and/or corrections to the information in the AEITs may be performed at any time since the decoder monitors the MGT continuously, where the most current copy of the version number is maintained. Updates and/or corrections to the AEIT (other than shifting) shall be signaled by increasing the version number by one. Besides listing the PIDs for all of the AEITs, the Master Guide Table (MGT) also lists a set of PIDs for Aggregate Extended Text Tables (AETTs). These tables carry relatively long text messages for describing events and virtual channels. Each AEIT has either zero or one associated AETT. Similarly, The SVCT has either zero or one associated AETT. 9.7 Requirements for Satellite Broadcast The rules governing the transport of PSIP tables for satellite are: 25 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 • Requirement 4: Every digital Transport Stream delivered via satellite shall include the STT, one or more SVCTs, the MGT and the first four Aggregate Event Information Tables (AEIT-0, AEIT-1, AEIT-2 and AEIT-3). For any region that makes use of the capability to change the RRT, that RRT shall be included in the TS if any content_advisory_descriptor in use refers to that region. For regions (such as the U.S.) where the definition of the rating system involves more information than the RRT conveys, transmission of that region’s RRT is not required and is not recommended. • Requirement 5: The PSIP tables shall describe all of the digital channels multiplexed in the Transport Stream. For convenience, the tables may optionally include information about other digital channels available in different satellite Transport Streams. 9.8 Code points defined in this Standard The following code points are defined in this Standard: • table_id value 0xDA, identifying the Satellite Virtual Channel Table • MGT table_type values 0x1600 to 0x16FF used to reference instances of the SVCT 9.9 Specifications This section describes the bit stream syntax and semantics for the Satellite Virtual Channel Table (SVCT), the Aggregate Event Information Table (AEIT), and the Aggregate Extended Text Table (AETT). The syntax and semantics for the System Time Table (STT), Master Guide table (MGT), Rating Region Table (RRT), descriptors, and the Multiple String Structure can be found in [6]. An extension to the MGT to allow it to refer to instances of the SVCT is defined in Section 9.9.4. 9.9.1 Satellite Virtual Channel Table (SVCT) The Satellite Virtual Channel Table (SVCT), like its cable and terrestrial broadcast counterparts, contains a list of attributes for virtual channels carried in the Transport Stream. Any changes in the virtual channel structure shall be conveyed with a new version number. The basic information contained in the body of the SVCT includes Transport Stream ID, major and minor channel number, short channel name, carrier frequency, program number, location field for extended text messages, service type, and modulation parameters. Additional information may be carried by descriptors, which may be placed in the descriptor loop after the basic information. Unlike cable and terrestrial applications where just one Virtual Channel Table is present in any given Transport Stream, in the satellite application more than one may be present. Different SVCTs are distinguished from one another by the SVCT_id parameter in the MPEG header portion of the table section. A receiver is expected to capture and record one or more SVCTs for use in navigation and service acquisition. At least one SVCT in each Transport Stream (and maybe more than one) will be applicable to a given receiving device. The mechanism by which a receiver knows which SVCT_id values correspond to tables of interest and which are of no value is typically tied to the Conditional Access function and is outside the scope of this standard. The Satellite Virtual Channel Table may be segmented into as many as 256 sections. One section may contain information for several virtual channels, but the information for one virtual channel shall not be segmented and put into two or more sections. Thus for each section, the first field after protocol_version shall be num_channels_in_section. 26 ATSC Direct-to-Home Satellite Broadcast Standard 30 July 2003 The Satellite Virtual Channel Table is carried in private sections with table ID 0xDA, and obeys the syntax and semantics given in Section 4. The following constraints apply to the Transport Stream packets carrying the SVCT sections: • PID for a given instance of an SVCT shall have the value given by the MGT for that instance, as identified by its SVCT_id. • transport_scrambling_control bits shall have the value ‘00’ • adaptation_field_control bits shall have the value ‘01’ The bit stream syntax for the Satellite Virtual Channel Table is shown in Table 9.3. The semantics for the SVCT are the same as the TVCT in [6] except for those fields explicitly defined below. Table 9.3 Bit Stream Syntax for the Satellite Virtual Channel Table Syntax No. of Bits Format satellite_virtual_channel_table_section () { table_id 8 0xDA section_syntax_indicator 1 ‘1’ private_indicator 1 ‘1’ reserved 2 ‘11’ section_length 12 uimsbf SVCT_subtype 8 uimsbf SVCT_id 8 uimsbf reserved 2 ‘11’ version_number 5 uimsbf current_next_indicator 1 bslbf section_number 8 uimsbf last_section_number 8 uimsbf protocol_version 8 uimsbf num_channels_in_section 8 uimsbf for(i=0; i