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/main/jmc-storage/docs/SCTE/ANSI SCTE 043 Digital Video Systems Characteristics Standard for Cable Television (2005).pdf Like all conversions the text below should be fully readable as UTF-8 unicode text. --------------------------------------------------------------- ENGINEERING COMMITTEE Digital Video Subcommittee AMERICAN NATIONAL STANDARD ANSI/SCTE 43 2005 Digital Video Systems Characteristics Standard for Cable Television i 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 nonmember 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 or Recommended Practices, and accepts full responsibility for any damage and/or claims arising from the adoption of such Standards or Recommended Practices. Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights. By publication of this standard, no position is taken with respect to the existence or validity of any patent rights in connection therewith. SCTE shall not be responsible for identifying patents for which a license may be required or for conducting inquires into the legal validity or scope of those patents that are brought to its attention. Patent holders who believe that they hold patents which are essential to the implementation of this standard have been requested to provide information about those patents and any related licensing terms and conditions. Any such declarations made before or after publication of this document are available on the SCTE web site at http://www.scte.org. All Rights Reserved © Society of Cable Telecommunications Engineers, Inc. 140 Philips Road Exton, PA 19341 ii TABLE OF CONTENTS 1. SCOPE........................................................................................................................................................1 2. REFERENCES............................................................................................................................................1 2.1 Normative references 1 2.2 Informative references 1 3. COMPLIANCE NOTATION.........................................................................................................................1 4. POSSIBLE VIDEO INPUTS........................................................................................................................2 5. SOURCE CODING SPECIFICATION .........................................................................................................2 5.1 Constraints with respect to ISO/IEC 13818-2 Main Profile 2 5.1.1 Sequence header constraints 2 5.1.2 Compression format constraints 3 5.1.3 Sequence extension constraints 4 5.1.4 Sequence display extension constraints 4 5.1.5 Picture header constraints 5 5.1.6 Picture coding constraints 5 5.2 Bit stream specifications beyond MPEG-2 5 5.2.1 Encoding and transport of advanced DTV captions 5 5.2.2 Encoding and transport of NTSC closed captions 5 5.2.3 Encoding of other NTSC VBI data 5 5.2.4 Encoding and transport of bar data 5 5.2.5 Encoding and transport of active format description data 6 LIST OF TABLES TABLE 1 STANDARDIZED VIDEO INPUT FORMATS ..........................................................................................................2 TABLE 2 SEQUENCE HEADER CONSTRAINTS ..................................................................................................................3 TABLE 3 COMPRESSION FORMAT CONSTRAINTS ............................................................................................................3 TABLE 4 SEQUENCE EXTENSION CONSTRAINTS..............................................................................................................4 TABLE 5 SEQUENCE DISPLAY EXTENSION CONSTRAINTS ...............................................................................................4 iii DIGITAL VIDEO SYSTEMS CHARACTERISTICS STANDARD FOR CABLE TELEVISION 1. SCOPE This document describes the characteristics and normative specifications for the Video Subsystem Standard for Cable Television. 2. REFERENCES 2.1 Normative references The following documents contain provisions that 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 parties to agreement based on this standard are encouraged to investigate the possibility of applying the most recent editions of the documents listed below. 1. ISO/IEC IS 13818-1, International Standard (2000), MPEG-2 Systems. 2. ISO/IEC IS 13818-2, International Standard (2000), MPEG-2 Video. 3. ISO/IEC 13818-2: 1996/Cor. 1: 2000 (E) MPEG 2 Video Technical Corrigendum 1. 4. CEA-608-B (2000), Line 21 Data Services 5. CEA-708-B (1999), Digital Television (DTV) Closed Captioning. 6. ANSI/SCTE 21(2001) (Formerly DVS 053), Standard for Carriage of NTSC VBI Data in Cable Digital Transport Streams. 7. ANSI/SCTE 20 (2004) (Formerly DVS 157), SCTE Proposed Standard Methods for Carriage of Closed Captions and Non-Real Time Sampled Video. 8. ATSC Standard: Digital Television Standard (A/53), Revision C with Amendment 1, 13 July 2004. 9. SMPTE 170M (1999), Television – Composite Analog Video Signal – NTSC for Studio Applications. 2.2 Informative references 11. SMPTE 274M (2003), Standard for television, 1920 x 1080 Scanning and Interface. 12. SMPTE 296M (2001), Standard for television, 1280 x 720 Scanning, Analog and Digital Representation, and Analog Interface. 13. ITU-R BT.601-5 (1995), Encoding parameters of digital television for studios. 14. ITU-R BT.709-4 (2000), Basic Parameter Values for the HDTV Standard for the Studio and for International Programme Exchange. 15. ITU-T J.83B Digital Video Transmission Standard for Cable Television. 16. ANSI/SCTE 07 (2000) (Formerly DVS 031), Digital Video Transmission System for Cable Television. 17. ANSI/SCTE 54 (2004), Digital Video Service Multiplex and Transport System Standard for Cable Television. 18. CEA-CEB10-A (2002), EIA-708-B Implementation Guidance. 3. 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 implementer. 1 4. POSSIBLE VIDEO INPUTS While not required by this standard, there are certain television production standards, shown in Table 1, that define video formats that relate to compression formats specified by this standard. Table 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 4831 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. 5. SOURCE CODING SPECIFICATION The video compression algorithm shall conform to the Main Profile syntax of ISO/IEC 13818-2 including Technical Corrigendum 1 and Technical Corrigendum 2. The allowable parameters shall be bounded by the upper limits specified for the Main Profile at High Level. Additionally, bit streams shall meet the constraints and extensions described in Sections 5.1 and 5.2. 5.1 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 syntactic elements that are restricted beyond the limits imposed 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. 5.1.1 Sequence header constraints Table 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. 1 Footnote: The number of active lines is not specified in ITU-R.601-5. “483” is the original number of lines specified in the NTSC standard. However current accepted practice in North America allows the line count to be anywhere from 480 to 486. 2 Table 2 Sequence Header Constraints Sequence Header Syntactic Element Allowed Value horizontal_size_value See Table 3 vertical_size_value See Table 3 aspect_ratio_information See Table 3 frame_rate_code See Table 3 bit_rate_value (64 QAM) ≤ 67500 bit_rate_value (256 QAM) ≤ 97000 vbv_buffer_size_value ≤ 488 The allowable values for the field bit_rate_value are application dependent. In the application of 64 QAM transmission, this field shall correspond to a bit rate which is less than or equal to 27.0 Mbps. In the higher data rate application of 256 QAM transmission, the corresponding bit rate is less than or equal to 38.8 Mbps. 5.1.2 Compression format constraints Table 3 lists the allowed compression formats. Table 3 Compression Format Constraints vertical_size_ horizontal_size_ aspect_ratio_ frame_rate_ progressive value value information code _sequence 10801 1920 1, 3 1, 2, 4, 5 1 10801 1920 1, 3 4, 5 0 10801 1440 3 1, 2, 4, 5 1 10801 1440 3 4, 5 0 720 1280 1, 3 1, 2, 4, 5, 7, 8 1 480 720 2, 3 1, 2, 4, 5, 7, 8 1 480 720 2, 3 4, 5 0 480 704 2, 3 1, 2, 4, 5, 7, 8 1 480 704 2, 3 4, 5 0 480 640 1, 2 1, 2, 4, 5, 7, 8 1 480 640 1, 2 4, 5 0 480 544 2 1 1 480 544 2 4 0 480 528 2 1 1 480 528 2 4 0 480 352 2 1 1 480 352 2 4 0 1 Note that 1088 lines are actually coded in order to satisfy the MPEG-2 requirement that the coded vertical size be a multiple of 16 (progressive scan) or 32 (interlaced scan). The bottom 8 lines are black, per MPEG rules. 3 Legend for MPEG-2 coded values in Table 3 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_sequence 0 = interlaced scan 1 = progressive scan 5.1.3 Sequence extension constraints A sequence_extension structure is required to be present after every sequence_header structure. This means that video shall be encoded in accordance with MPEG-2. Table 4 identifies parameters in the sequence extension part of a bit stream that shall be constrained by the video subsystem and lists the allowed values for each. Table 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, Section 8 that is consistent with the parameters of the video elementary stream. 5.1.4 Sequence display extension constraints Table 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 5 Sequence Display Extension Constraints Sequence display extension syntactic element Allowed values video_format ‘000’ 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 are allowed in the transmitted bit stream, it is noted that ITU-R BT.709 and SMPTE 170M are the most likely to be in common use. The preferred values for color_primaries, transfer_characteristics and matrix_coefficients are defined to be ITU-R BT.709 (value 0x01 in all three cases) for all compression formats in Table 3. Except for those Table 3 formats having vertical_size value = 480, frame_rate_code = 4 and progressive_sequence = 0 (the so-called "NTSC formats"), the colorimetry shall be explicitly indicated in the sequence_display_extension. If the so-called "NTSC formats" do not have the colorimetry explicitly indicated in the sequence_display_extension, they shall be encoded in accordance with SMPTE 170M. Note: If the original signal source is an ATSC stream and the colorimetry is not explicitly indicated in the sequence_display_extension, the signal may have been encoded in accordance with ITU-R BT.709. 4 5.1.5 Picture header constraints In all cases other than when vbv_delay has been set to the value 0xFFFF (see [1]), the value of vbv_delay shall be vbv_delay <= 45000. Informative note: In conformance with [1] decoders are expected to use vbv_delay for buffer management only when the STD descriptor is present in the Transport Stream for the program being decoded and the leak_valid flag in the descriptor is set to ‘0’. The majority of the broadcast systems currently deployed do not include the STD descriptor and, therefore, decoders are expected to manage the buffer using the time stamps (i.e., PCR and PTS) in the Transport Stream applicable to the program being decoded. If vbv_delay is used for buffer size management, the video ES bit rate is limited to 16 Mbps because of the constraint on the size of receiver buffer, which 8 MB (see Table 2 where vbv_buffer_size <=488). 5.1.6 Picture coding constraints Use of progressive_frame in [2] is constrained as follows: If progressive_frame is set to ‘1’, frame_pred_frame_dct shall be ‘1’. 5.2 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. 5.2.1 Encoding and transport of advanced DTV captions Advanced DTV closed captions, when present, shall be encoded in accordance with EIA-708-B and shall be transported in accordance with ATSC A/53-B as modified by Amendment 1 to ATSC A/53-B (note that advanced DTV captions are signaled in A/53B by setting the cc_type field to '10' or '11'). 5.2.2 Encoding and transport of NTSC closed captions Line 21 caption data, encoded in accordance with CEA-608-B, when present shall be transported in accordance with ANSI/SCTE 20 or ATSC A/53B as modified by Amendment 1 to ATSC A/53B or both. (Note that such Line 21 caption data is signaled in A/53B by setting the cc_type field to '00' or '01'.). In addition, the interleaving of the sequence SHALL be as follows: After the first user_data_start_code for SCTE 20 user data is sent (followed by the line 21 caption data per SCTE 20), then the second user_data_start_code is sent (followed by the ATSC A/53B user data which may include both CEA-608-B and CEA-708-B formats). Note that other data may be present in Line 21. 5.2.3 Encoding of other NTSC VBI data For transport of other NTSC VBI data please see references [6] and [7]. 5.2.4 Encoding and transport of bar data Bar data, when present, shall be encoded and transported in accordance with ATSC A/53-B as modified by Amendment 1 to ATSC A/53-B. 5 5.2.5 Encoding and transport of active format description data Active format description data, when present, shall be encoded and transported in accordance with ATSC A/53-B as modified by Amendment 1 to ATSC A/53-B. 6