1、 Copyright 2015 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved January 2, 2015 Table of Contents Page Foreword . 2 Intellectual Property 2 Introduction 2 1 Scope . 3 2 Conformance Notation . 3 3 Normative References . 3 4 Def
2、initions and Acronyms 4 5 Format of VANC Data Packets 4 6 UDW Data Format from MPEG-2 TS . 5 Annex A Bibliography (Informative) 7 Annex B Comments on the Preferred Location of VANC Packets (Informative) . 8 Page 1 of 8 pages SMPTE ST 2031:2015 Revision of SMPTE 2031-2007 SMPTE STANDARD Carriage of D
3、VB/SCTE VBI Data in VANC SMPTE ST 2031:2015 Page 2 of 8 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 count
4、ries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineering Guidelines, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other st
5、andards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with the rules given in its Standards Operations Manual. SMPTE ST 2031 was prepared by Technology Committee 24TB. Intellectual Property At the time of publication no notice had been re
6、ceived by SMPTE claiming patent rights essential to the implementation of this Standard. However, attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be held responsible for identifying any or all such patent rights. I
7、ntroduction This section is entirely informative and does not form an integral part of this Engineering Document. With the spread of “digital turnaround” systems worldwide, where MPEG-2, AVC, or VC-1 compressed video signals are returned to digital baseband before being re-compressed, the proper han
8、dling of analog VBI signals in the decoded SDI signal (as reconstructed digital samples of an analog waveform) presents issues, as the decoders reconstructed sampling instants does not always perfectly align with the downstream encoders sampling instants. In addition, it makes little sense to artifi
9、cially reconstruct digital representations of analog waveforms which themselves simply carry digital information. This Standard provides a standardized method of retrieving this VBI data from MPEG-2 TS and placing the base data into VANC. This Standard specifies how to carry the above data types in
10、VANC as binary values based on their root transport standards. SMPTE ST 2031:2015 Page 3 of 8 pages 1 Scope This Standard specifies how to carry the digital values resulting from defined standardized data streams carried in MPEG-2 Transport Streams (TS) as specified by either DVB/ETSI EN 301 775 or
11、ANSI/SCTE 127 (or both) as ancillary data packets in the vertical ancillary data space (VANC). 2 Conformance Notation Normative text is text that describes elements of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative text is te
12、xt that is potentially helpful to the user, but not indispensable, and can be removed, changed, or added editorially without affecting interoperability. Informative text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction, any sect
13、ion explicitly labeled as “Informative“ or individual paragraphs that start with “Note:” The keywords “shall“ and “shall not“ indicate requirements strictly to be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ indicate t
14、hat, among several possibilities, one is recommended as particularly suitable, without mentioning or excluding others; or that a certain course of action is preferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibit
15、ed. The keywords “may“ and “need not“ indicate courses of action permissible within the limits of the document. The keyword “reserved” indicates a provision that is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addi
16、tion indicates that the provision will never be defined in the future. A conformant implementation according to this document is one that includes all mandatory provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not implemen
17、t optional provisions (“may“) and need not implement them as described. Unless otherwise specified, the order of precedence of the types of normative information in this document shall be as follows: Normative prose shall be the authoritative definition; Tables shall be next; followed by formal lang
18、uages; then figures; and then any other language forms. 3 Normative References The following standards contain provisions which, 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 revisio
19、n, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. SMPTE ST 291-1:2011, Ancillary Data Packet and Space Formatting ETSI EN 301 775, v1.2.1 (2003-05): Specification for the Carriage of
20、 Vertical Blanking Information (VBI) Data in DVB Bitstreams ANSI/SCTE 127-2007, Carriage of Vertical Blanking Interval (VBI) Data in North American Digital Television Bitstreams SMPTE ST 2031:2015 Page 4 of 8 pages 4 Definitions and Acronyms NOT: The logical function NOT is the logical inverse of th
21、e bit or bits designated. TS: (MPEG-2) Transport Stream. UDW: “user data word.” See SMPTE ST 291-1. Uimsbf: Unsigned integer, most significant bit first. Note: The byte order of multi-byte uimsbf words is most significant byte first. 5 Format of VANC Data Packets Each data packet shall comply with t
22、he format defined in SMPTE ST 291-1 for a 10-bit type 2 ancillary space (ANC) packet. It consists of the ancillary data flag (ADF), the data ID (DID), the secondary data ID (SDID), the data count (DC), the user data words (UDW), and the checksum (CS). The UDW shall consist of the data_field( ) struc
23、tures from either EN 301 775 or ANSI/SCTE 127 as identified in Table 2 of this document, and shall be formatted into SMPTE ST 291-1 packets as shown in Table 1 below. The format of the VBI data contained within each data_field( ) structure shall be determined from the value of data_identifier and da
24、ta_unit_id (see Section 4.4.2 of EN 301 775). The DID word shall be set to the value 41h. The SDID word shall be set to the value of 08h. DC shall be the value of data_unit_length plus three (3). Note: data_unit_length is the size of the data_field( ) structure as defined in Section 4 of EN 301 775
25、or in Section 7 of ANSI/SCTE 127. Each VBI data_field( ) shall begin in a new VANC data packet. In the case where a single PES_data_field( ) contains multiple VBI data_field( ) types, a new VANC data packet shall be constructed for each VBI data_field( ) so contained. Each SMPTE ST 291-1 packet shal
26、l be placed into the Luma (Y) data stream within vertical ancillary data space (VANC) using the structure specified by Table 1. Table 1 UDW format Syntax No. of bits Format data_identifier 8 uimsbf data_unit_id 8 uimsbf data_unit_length 8 uimsbf data_field() variable Each byte of the TS data shall b
27、e placed into bits 0 to 7 of the 10-bit UDW, with the low order bit going into bit 0 of the 10-bit word. Bit b8 is the even parity for bits b7 through b0 and bit b9 is NOT b8. Stuffing bytes in the EN 301 775 PES_data_field () shall be ignored. Note: Each (VBI) data_field() structure contains a line
28、_offset and field_parity value which permits correct replacement of the analog VBI waveforms if required. SMPTE ST 2031:2015 Page 5 of 8 pages Note: Receiver designers need to recognize that some deployed equipment may not conform to the restrictions of the placement in the Luma (Y) data stream. Rec
29、eivers conforming to this document ought to receive data transmitted in any data stream within ancillary data space. Additional background information regarding placement in VANC is found in Annex B. 6 UDW Data Format from MPEG-2 TS Note: The VBI data to be carried in the UDW has been formatted into
30、 MPEG-2 PES packets as specified by sections 4.3 through 4.7 of EN 301 775, which resulted in one or more MPEG-2 TS packets in an MPEG-2 Transport Stream. The value of data_identifier shall be in the range 0x10 to 0x1F or 0x99 as defined in Table 2 of EN 301 775 or in ANSI/SCTE 127. The value of dat
31、a_unit_id shall be as shown in Table 2 of this document. The VBI data_field( ) structure which was used for each value of data_unit_id shall be as defined in Table 2. data_field( ) structures identified by data_unit_id values shown in Table 2 as “Not supported by this document,” “SCTE reserved ,”or
32、“DVB reserved” shall not be placed into VANC data packets and should be ignored. SMPTE ST 2031:2015 Page 6 of 8 pages Table 2 data_unit_id values data_unit_id Value Service data_field()1 0x00 to 0x01 DVB reserved 0x02 EBU Teletext non-subtitle data txt_data_field () 0x03 EBU Teletext subtitle data t
33、xt_data_field () 0x04 to 0x7F DVB reserved 0x80 to 0xBF User defined 0xC0 Inverted Teletext txt_data_field () 0xC1 DVB reserved 0xC2 DVB reserved 0xC3 VPS vps_data_field() 0xC4 WSS wss_data_field () 0xC5 CEA-608 data closed_captioning_data_field () 0xC6 Not supported by this document 0xC7 to 0xCF Us
34、er defined 0xD0 AMOL48 amol48_data_field () 0xD1 AMOL96 amol96_data_field () 0xD2 SCTE reserved 0xD3 Protected 12 0xD4 Protected 22 0xD5 NABTS nabts_data_field () 0xD6 TVG2X tvg2x_data_field () 0xD7 Copy Protection cp_data_field() 0xD8 Protected 32 0xD9 VITC vitc_data_field () 0xDA to 0xE5 SCTE rese
35、rved 0xE6 to 0xFE SCTE User defined 0xFF MPEG stuffing Note: data_unit_id values in the range 0x00 to 0xCF are DVB defined in EN 301 775, while those in the range 0xD0 to 0xFF are defined in ANSI/SCTE 127. Equipment should provide support of VBI data_field( ) structures identified by SCTE user defin
36、ed data_unit_id values 0xE6 to 0xFE, only if the internal structure of the VBI data_field( ) follows the pattern of those defined in ANSI/SCTE 127 and the total size of the VBI data_field( ) is less than or equal to 252 bytes. 1 data_field() name as specified by either EN 301 775 or ANSI/SCTE 127 as
37、 applicable. 2 In use by legacy equipment not supported by this document. SMPTE ST 2031:2015 Page 7 of 8 pages Annex A Bibliography (Informative) CEA-608-E (2008), Line 21 Data Services ETSI EN 300 472 V1.3.1 (2003-05): Specification for Conveying ITU-R System B Teletext in DVB Bitstreams SMPTE RP 2
38、91-2:2013, Ancillary Data Space Use 4:2:2 SDTV and HDTV Component Systems and 4:2:2 2048 x 1080 Production Image Formats SMPTE ST 2031:2015 Page 8 of 8 pages Annex B Comments on the Preferred Location of VANC Packets (Informative) Notwithstanding the possibility that the VANC packets can be placed o
39、n any line in the vertical blanking interval, it is desirable to further constrain the location to a preferred line to improve the probability of successful passage through the production process. Many devices in the studio processing chain will pass data on only a small subset of lines in the verti
40、cal ancillary space and some devices (e.g., production switchers, digital video effects units, and video servers) might not pass VANC packets at all. This will have to be taken into account in the distribution system design and choice of data location in VANC. Some recording devices record only one
41、line of data from the vertical blanking interval while others record up to 11 lines. These recorders select the lines that they record, or have other constraints. However, it is a common practice to set them to record three consecutive lines starting at the second line after the switching line. This
42、 constrains the available lines to the second line, the third line, and the fourth line after the switching line. Some devices do not test for existing ANC packets and consequently overwrite existing ANC packets. These devices might insert data on any line after the switching line. ANC packets containing VBI Data are typically embedded in the video signal late in the production process. There can be routing switchers downstream of the inserting device, and users will need to heed their capabilities.
