1、 Rec. ITU-R BT.1366-2 1 RECOMMENDATION ITU-R BT.1366-2 Transmission of time code and control code in the ancillary data space of a digital television stream according to Recommendations ITU-R BT.656*, ITU-R BT.799*and ITU-R BT.1120*(Question ITU-R 42/6) (1998-2007-2008) Compliance with this Recommen
2、dation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall” or some other obligatory language such as
3、“must” and the negative equivalents are used to express requirements. The use of such words shall in no way be construed to imply partial or total compliance with this Recommendation. Scope This Recommendation defines a transmission format for conveyance of linear (LTC) or vertical interval (VITC) t
4、ime-code data formatted according to Recommendation ITU-R BR.780-2 in 8- or 10-bit digital television data interfaces according to Recommendations ITU-R BT.656, ITU-R BT.799 and ITU-R BT.1120. The ITU Radiocommunication Assembly, considering a) that the use of time-code signals is well-established i
5、n the area of post-production; b) that many countries have installed digital television production facilities based on the use of digital video components conforming to Recommendations ITU-R BT.601, ITU-R BT.656 or ITU-R BT.1120; c) that there exists the capacity within a signal conforming to Recomm
6、endations ITU-R BT.656, ITU-R BT.799 and ITU-R BT.1120 for additional ancillary data signals to be multiplexed with the video data signal; d) that there are operational and economic benefits to be achieved by the multiplexing of ancillary data signals with the video data signal; e) that the operatio
7、nal benefits are increased if a minimum of different formats are used for ancillary data signals; f) that the exchange of programme material between and within organizations is facilitated if a common format of time-code signal is used; *Recommendation ITU-R BT.656 Interface for digital component vi
8、deo signals in 525-line and 625-line television systems operating at the 4:2:2 level of Recommendation ITU-R BT.601. *Recommendation ITU-R BT.799 Interface for digital component video signals in 525-line and 625-line television systems operating at the 4:4:4 level of Recommendation ITU-R BT.601. *Re
9、commendation ITU-R BT.1120 Digital interfaces for HDTV studio signals. 2 Rec. ITU-R BT.1366-2 g) that extension of the capacity of the time-code signal to carry additional information is desirable; h) that progressive image production beyond 30 Hz requires the use of ancillary time-code packets, rec
10、ommends 1 that the time-code ancillary data signal format described in Annex 1 to this Recommendation should be used for the interfaces defined in Recommendations ITU-R BT.656, ITU-R BT.799 and ITU-R BT.1120. Annex 1 1 Introduction This Recommendation defines a transmission format for conveyance of
11、linear (LTC) or vertical interval (VITC) time-code data formatted according to ITU-R BR.780-2 in 8- or 10-bit digital television data interfaces according to ITU-R BT.656, ITU-R BT.799 and ITU-R BT.1120. Time-code information is transmitted in the ancillary data space as defined in Recommendation IT
12、U-R BT.1364. Multiple codes can be transmitted within a single digital video data stream. Other time information, such as real-time clock, DTTR tape timer information, and other user-defined information, may also be carried in the ancillary time-code packet instead of time code. The actual informati
13、on transmitted through the interface is identified by the coding of a distributed binary bit. 2 Normative references 2.1 Normative provisions The following Recommendations contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of the publi
14、cation, the editions indicated were valid. All standards and Recommendations are subject to revision, and parties to agreements based on this practice are encouraged to investigate the possibility of applying the most recent edition of the standards and Recommendations indicated below. 2.2 Normative
15、 references Recommendation ITU-R BR.780-2 Time and control code standards, for production applications in order to facilitate the international exchange of television programmes on magnetic tapes. Recommendation ITU-R BT.1364 Format of ancillary data signals carried in digital component studio inter
16、faces. 3 Ancillary time-code format (ATC)13.1 One ancillary data packet of constant length excluding ancillary data flag shall fully represent an ancillary time-code (ATC) word. 1ATC is used to convey time-code data formatted as LTC, VITC, or both. Rec. ITU-R BT.1366-2 3 3.2 The ancillary time-code
17、packet shall be type 2, having a data identification (DID) and a secondary data identification (SDID). The DID and SDID shall be set to: DID = 60h SDID = 60h 3.3 The data count (DC) value for ancillary time code shall be set to: DC = 10h 4 Format of user data words in ancillary time-code packet 4.1
18、All user data words in the ancillary time-code packets are formatted as shown in Table 1. NOTE 1 References to user data word (UDW) bits in this Recommendation are for a 10-bit UDW word. Correspondence between an 8-bit word and a 10-bit word is shown in Table 1. TABLE 1 User data words format UDW10b
19、it (10-bit words) UDW8bit (8-bit words) Assignment b0 (LSB) N/A Set to “0” in 10-bit words. N/A in 8-bit words b1 N/A Set to “0” in 10-bit words. N/A in 8-bit words b2 b0 Set to “0” in 10-bit and 8-bit words b3 b1 Distributed binary bit (DBB) b4 b2 ANC binary group LSB b5 b3 ANC binary group b6 b4 A
20、NC binary group b7 b5 ANC binary group MSB b8 b6 10 bit systems: Even parity for data contained in UDW bit 7 through bit 0 8 bit systems: Even parity for data contained in UDW bit 5 through bit 0 b9 (MSB) b7 10 bit: Not bit 8, 8 bit: Not bit 6 4.1.1 Bit b7 through bit b4 of the UDW10-1 through UDW10
21、-16 shall contain the time-code information and additional information as per Recommendation ITU-R BR.780-2. 4.2 Bit b3 of the UDW10-1 through UDW10-16 form two groups of distributed binary bits DBB 1 and DBB 2 (see Table 3). 4.2.1 The first group of distributed binary bits (DBB 1) is formed by bit
22、3 of UDW10-1 through UDW10-8, where UDW10-1 (b3) represents the LSB and UDW10-8 (b3) represents the MSB. 4.2.2 The second group of distributed binary bits (DBB 2) is formed by bit 3 of UDW10-9 through UDW10-16, where UDW10-9 (b3) represents the LSB and UDW10-16 (b3) represents the MSB. 4.3 Bits b7 t
23、hrough b4 form an ancillary binary group into which the time code is mapped. Bits b4 of the UDW10represents the LSB of this group. 4.4 Information coded in the distributed binary bit group is defined in Table 3. 4 Rec. ITU-R BT.1366-2 4.4.1 Bits b4 through b0 of the distributed binary bit group DBB
24、2 convey VITC line number location indicating the position of VITC data on the output digital video signal interface within the vertical blanking interval. The line select number depends on the television system and shall be constrained to a range as shown in Table 2. TABLE 2 Line select number VITC
25、 line select 525/60I 625/50I bit b5 = x bit b5 = 1 bit b5 = x bit b5 = 1 DBB 2 bits b4 through b0 VITC on line N Repeated VITC on line (N+2) VITC on line N Repeated VITC on line (N+2) B4 b3 b2 b1 b0 field 1 (odd) field 2 (even) field 1 (odd) field 2 (even) field 1 (odd) field 2 (even) field 1 (odd)
26、field 2 (even) 0 0 1 1 0 6/319 8/321 0 0 1 1 1 7/320 9/322 0 1 0 0 0 8/321 10/323 0 1 0 0 1 9/322 11/324 0 1 0 1 0 10/273 12/275 10/323 12/325 0 1 0 1 1 11/274 13/276 11/324 13/326 0 1 1 0 0 12/275 14/277 12/325 14/327 0 1 1 0 1 13/276 15/278 13/326 15/328 0 1 1 1 0 14/277 16/279 14/327 16/329 0 1 1
27、 1 1 15/278 17/280 15/328 17/330 1 0 0 0 0 16/279 18/281 16/329 18/331 1 0 0 0 1 17/280 19/282 17/330 19/332 1 0 0 1 0 18/281 20/283 18/331 20/333 1 0 0 1 1 19/282 19/332 21/334 1 0 1 0 0 20/283 20/333 22/335 1 0 1 0 1 21/334 1 0 1 1 0 22/335 NOTE x = irrelevant. 4.4.2 Bit b5 of DBB 2 when set to “1
28、” shall signify that the VITC word carried in the ancillary time-code word, when converted to an analogue video output signal, shall be inserted on the selected line number and shall be repeated again on the selected line number +2 (see Table 2, bit b5 = 1). 4.4.3 Bits b7 and b6 of the DBB 2 word re
29、present different time-code condition bits (see Table 3). Data errors indicated by the error detection system of the received time-code signal at the input receiving interface to the ancillary time-code formatter and the type of processing of receiving user bits shall be signalled by these bits in t
30、he transmitted ATC word. The coding of these two bits is shown in Table 4. Rec. ITU-R BT.1366-2 5 TABLE 3 Distributed binary bit group coding DBB group Bit 3 of UDW Distributed binary bit (DBB) MSB LSB Definition 0 0 0 0 0 0 0 0 Longitudinal time code 0 0 0 0 0 0 0 1 Vertical interval time code No.
31、1 0 0 0 0 0 0 1 0 Vertical interval time code No. 2 DBB 1 UDW10-1 through UDW10-8 0 0 0 0 0 0 1 1 through 0 0 0 0 0 1 1 1 User defined 0 0 0 0 1 0 0 0 through 0 1 1 1 1 1 1 1 Locally generated time address and user data (user defined) 1 0 0 0 0 0 0 0 through 1 1 1 1 1 1 1 1 Reserved UDW10-9 b0 VITC
32、line select (LSB) (Note) UDW10-10 b1 VITC line select (Note) UDW10-11 b2 VITC line select (Note) DBB 2 UDW10-12 b3 VITC line select (Note) UDW10-13 b4 VITC line select (MSB) (Note) UDW10-14 b5 VITC line duplication (Note) UDW10-15 b6 Time-code validity UDW10-16 b7 (User bits) process bit NOTE 1 Thes
33、e bits are not used in interfaces which are in accordance with Recommendation ITU-R BT.1120, and shall be set to logical zero. 4.5 Mapping of the time-code data into the UDW 1 thorough UDW 16 of the ancillary time-code data packet is shown in Table 5. TABLE 4 Coding of validity and process bits VITC
34、 validity bit (b6) and process bit (b7) Definition b6 = 0 No time-code error received or locally generated time-code address b6 = 1 Transmitted time code interpolated from previous time code (received a time-code error) b7 = 0 Binary group of user bits in time-code data stream are processed to compe
35、nsate for latency b7 = 1 Binary groups of user bits in time-code data stream are only retransmitted (no delay compensation) 6 Rec. ITU-R BT.1366-2 TABLE 5 Mapping of time-code data into UDW UDW Time-code bit Time-code definitions (as per Rec. ITU-R BR.780-2) 1 b4 b5 b6 b7 0 1 2 3 Units of frames 1 U
36、nits of frames 2 Units of frames 4 Units of frames 8 2 b4 b5 b6 b7 4 5 6 7 LSB binary group 1 xxx binary group 1 xxx binary group 1 MSB binary group 1 3 b4 b5 b6 b7 8 9 10 11 Tens of frames 10 Tens of frames 20 Flag Flag 4 b4 b5 b6 b7 12 13 14 15 LSB binary group 2 xxx binary group 2 xxx binary grou
37、p 2 MSB binary group 2 5 b4 b5 b6 b7 16 17 18 19 Units of seconds 1 Units of seconds 2 Units of seconds 4 Units of seconds 8 6 b4 b5 b6 b7 20 21 22 23 LSB binary group 3 xxx binary group 3 xxx binary group 3 MSB binary group 3 7 b4 b5 b6 b7 24 25 26 27 Tens of seconds 10 Tens of seconds 20 Tens of s
38、econds 40 Flag 8 b4 b5 b6 b7 28 29 30 31 LSB binary group 4 xxx binary group 4 xxx binary group 4 MSB binary group 4 9 b4 b5 b6 b7 32 33 34 35 Units of minutes 1 Units of minutes 2 Units of minutes 4 Units of minutes 8 10 b4 b5 b6 b7 36 37 38 39 LSB binary group 5 xxx binary group 5 xxx binary group
39、 5 MSB binary group 5 11 b4 b5 b6 b7 40 41 42 43 Tens of minutes 10 Tens of minutes 20 Tens of minutes 40 Flag Rec. ITU-R BT.1366-2 7 TABLE 5 (end) UDW Time-code bit Time-code definitions (as per Rec. ITU-R BR.780-2) 12 b4 b5 b6 b7 44 45 46 47 LSB binary group 6 xxx binary group 6 xxx binary group 6
40、 MSB binary group 6 13 b4 b5 b6 b7 48 49 50 51 Units of hours 1 Units of hours 2 Units of hours 4 Units of hours 8 14 b4 b5 b6 b7 52 53 54 55 LSB binary group 7 xxx binary group 7 xxx binary group 7 MSB binary group 7 15 b4 b5 b6 b7 56 57 58 59 Tens of hours 10 Tens of hours 20 Flag Flag 16 b4 b5 b6
41、 b7 60 61 62 63 LSB binary group 8 xxx binary group 8 xxx binary group 8 MSB binary group 8 NOTE 1 Appropriate flag information for each television system as per Recommendation ITU-R BR.780-2 is inserted into the corresponding positions of Table 5 marked as “flag.” 5 Transmission of ancillary time-c
42、ode packets 5.1 Multiple transmissions of ancillary time-code packets per video frame code information are permissible under the provisions of this Recommendation. NOTE 1 This Recommendation permits transmission of different ATC packets within a single video frame; as for example an ATC packet conta
43、ining LTC information and a second ATC packet containing VITC information. The time-code information in these two ATC packets shall correspond to the relevant video frame (see 6.2). 5.2 Transmission of ancillary time-code packets should be at least once per frame for LTC data word and once per field
44、 for VITC data word. 5.2.1 Only the 64 information bits of time code are transferred to the ATC. The LTC sync word (bits 64-79) and the VITC (“1”/”0”) sync bit pairs and CRC word are omitted from the ancillary time-code packets. 6 Ancillary time-code packets location 6.1 Insertion of ancillary time-
45、code (ATC) packets into any available location in the digital data stream is permitted under the provisions of this recommendation, but it is recommended that packet insertion occurs within the vertical blanking interval as defined by the line standard in use (prior) (see Note 1) to the normal verti
46、cal switching point defined in SMPTE RP 168-2002 (Definition of vertical Interval Switching Point for Synchronous Switching). 8 Rec. ITU-R BT.1366-2 NOTE 1 ATC information should correspond directly to the video after the vertical switching point. For that reason the insertion of the ATC after the n
47、ormal vertical switching point should be considered as the preferred location. 6.1.1 For systems implementing ITU-R BT.1120 the following ATC insertion points should be considered as the preferred location. ATC packets shall be inserted into the Y channel of the interface. Type of time code Location
48、 for multiplexing in 1125-line interlace systems Location for multiplexing in 1125-line progressive and PsF systems Packet for LTC Horizontal ancillary data space of line 10 Packet for VITC #1 Horizontal ancillary data space of line 9 Packet for VITC #2 Horizontal ancillary data space of line 571 Ho
49、rizontal ancillary data space of line 11 Packet for others Available any horizontal ancillary data space except lines 9, 10 and 571 Any lines except lines 9 and 10 6.1.2 When dual link ITU-R BT.1120 interfaces are used for a 1125 line progressive system, the locations of embedded time-code packets in each link are the same as for 1125-line interlaced formats. 6.1.3 When ITU-R BT.656 or ITU-R BT.799 interfaces are used for SDTV signals the preferred location for insertion of ATC packets is in vertical ancillary data space, f
