1、 Rec. ITU-R BT.1381-3 1 RECOMMENDATION ITU-R BT.1381-3*Serial digital interface-based transport interface for compressed television signals and packetized data in networked television production based on Recommendation ITU-R BT.656*(Question ITU-R 5/6) (1998-2001-2006-2007) Scope This Recommendation
2、 specifies a data stream used to transport packetized data within a studio/production centre environment. The data packets and synchronizing signals are compatible with Recommendation ITU-R BT.656 (see Fig. 1). The ITU Radiocommunication Assembly, considering a) that the so-called serial digital int
3、erface (SDI) is in widespread use in television production studios and that it is documented in Recommendation ITU-R BT.656; b) that Recommendation ITU-R BR.1356 User requirements for application of compression in television production, already exists; c) that maintaining video signals in compressed
4、 form as far as possible throughout the production and post-production process offers the potential of increased operating efficiency; d) that programme data composed of audio, compressed video, metadata and other packetized data should be streamed in a single or multiple container(s); e) that a tra
5、nsport mechanism must be established which allows point-to-point and point-to-multipoint routing of these data through a digital production and post-production chain; f) that the transport should allow synchronous data transfer to alleviate absolute and relative timing between programme data; g) tha
6、t the transport mechanism should allow non-real time transfer of programme data, recommends 1 that for applications based on the SDI infrastructure in networked production and post-production based on Recommendation ITU-R BT.656, the serial data transport interface (SDTI) described in Annex 1 should
7、 be used. *This Recommendation should be brought to the attention of the International Electrotechnical Commission (IEC). *Recommendation ITU-R BT.656-4 Interfaces for digital component video signals in 525-line and 625-line television systems operating at the 4:2:2 level of Recommendation ITU-R BT.
8、601. 2 Rec. ITU-R BT.1381-3 Annex 1 SDI-based transport interface for compressed television signals and packetized data in networked television production 1 Introduction The carriage of packetized data utilizing the serial digital interface as defined by Recommendation ITU-R BT.656 is defined in thi
9、s Recommendation. The formatting of the packetized data and the assigned values is covered by this Recommendation. Specific applications are covered by other Recommendations. 1.1 Parameters of the protocol are compatible with the 4:2:2 component SDI format as shown in Fig. 2. 1.2 The data stream is
10、intended to transport any packetized data signal over the digital active lines that have a maximum data rate up to (approximately) 200 Mbit/s. 1.3 Additional texts will describe specific applications of this Recommendation and will include details of data formatting and other parameters, such as com
11、pression and error correction, if applicable. Rec. ITU-R BT.1381-3 3 2 Normative references Recommendation ITU-R BT.656 Interface for digital component video 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.1364
12、Format of ancillary data signals carried in digital component studio interfaces. 3 General specifications 3.1 This Recommendation describes the assembly of a stream of 10-bit words. The resulting word stream should be serialized, scrambled, coded, and interfaced according to Recommendation ITU-R BT.
13、656. 3.2 The word clock rate should be 27 MHz in accordance with Recommendation ITU-R BT.601. 3.3 The data word length should be 10 bits: B0 to B9. B9 is the most significant bit (MSB). The nominal data rate for the resulting serial data stream should be 270 Mbit/s. 3.4 The timing reference signals
14、(EAV and SAV) occur on every line, and should be as described in Recommendation ITU-R BT.656. 3.5 An ANC data packet forming the header data is placed after EAV, as specified in 4. All payload is placed between SAV and EAV. The space after the header data but before SAV is available for ANC data as
15、specified by Recommendation ITU-R BT.1364. 3.6 The signal levels and specifications should be as described in Recommendation ITU-R BT.656. 3.7 The connector shall have mechanical characteristics conforming to the standard BNC type (IEC 61169-8 (2007-2) Part 8: Sectional specification RF coaxial conn
16、ectors with inner diameter of outer conductor 6.5 mm (0.256 in) with bayonet lock-characteristic impedance 50 (type BNC). NOTE 1 IEC 61169-8 (2007-2) is available in electronic version at the following address: http:/www.itu.int/md/R03-WP6A-C-0142/en. 4 Header data The data structure for the header
17、data should conform to Recommendation ITU-R BT.1364 ancillary data packet (type 2). The header data should be located immediately after the EAV as shown in Fig. 3. Ancillary data flag (ADF) Data ID (DID) Secondary data ID (SDID) 53 words Data count (DC) Header data 46 words Checksum (CS) 4 Rec. ITU-
18、R BT.1381-3 The header data should include the following: Line number 2 words Line number CRC 2 words Code and authorized address identifier (AAI) 1 word Destination address 16 words Source address 16 words Block type 1 word CRC flag 1 word Reserved data 5 words Header CRC 2 words 4.1 Ancillary data
19、 formatting The ADF, DID, SDID, DC, and CS should conform to Recommendation ITU-R BT.1364. 4.1.1 Data ID (DID) The data ID should have the value of 40hfor B7 to B0. B8 is even parity for B7 to B0 B9 is the complement of B8. 4.1.2 Secondary data ID (SDID) The secondary data ID should have the value o
20、f 01hfor B7 to B0. B8 is even parity for B7 to B0 B9 is the complement of B8. 4.1.3 Data count (DC) The data count should represent 46 words for the header with the value 2Ehfor B7 to B0. B8 is even parity for B7 to B0 B9 is the complement of B8. Rec. ITU-R BT.1381-3 5 4.2 Line number 4.2.1 The line
21、 number should represent the number from 1 to 525 for 525-line systems, and 1 to 625 for 625-line systems in order to check the data continuity. 4.2.2 The line number should be contained within L9 to L0. R5 to R0 are reserved and set to zero (see Fig. 4). EP1 is even parity for L7 to L0 EP2 is even
22、parity for R5 to R0, L9, L8. 4.3 Line number CRC Following each line number, a line number CRC should be inserted. The line number CRC applies to the data ID through the line number for the entire ten bits (see Fig. 5). The generator polynomial for the line number CRC should be G(x) = x18+ x5+ x4+ 1
23、, which conforms to ITU-T Recommendation X.25 Interface between Data Terminal Equipment (DTE) and Data Circuit-Terminating Equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit (see Fig. 6). Line number CRC should be contained in C17 to
24、 C0, and the initial value should be set to all ones. 4.4 Code and AAI Both code and AAI should consist of four bits (see Fig. 7). Code: B3 to B0 AAI: B7 to B4 B8 is even parity for B7 to B0 B9 is the complement of B8. 6 Rec. ITU-R BT.1381-3 4.4.1 Code The code is intended to identify the length of
25、the payload with the following values. The payload should be contained in the area between SAV and EAV. B3 B2 B1 B0 Reserved for SDI: 0 0 0 0 1 440-word payload: 0 0 0 1 NOTE 1 Code = “0000” is used where uncompressed 4:2:2 data are transmitted in the following line. However, uncompressed and compre
26、ssed signals should not be mixed in the same signal. Other codes should be registered with SMPTE (see 7). NOTE 2 Code = “1000” is reserved for 143 Mbit/s applications. Rec. ITU-R BT.1381-3 7 4.4.2 AAI The AAI is intended to identify the format of the destination and source address words with 16 diff
27、erent states. B7 B6 B5 B4 Unspecified format: 0 0 0 0 IPv6 address*: 0 0 0 1 * IETF (Internet Engineering Task Force) Request for Comments (RFC-1883), IPv6, Internet Standard Track Protocol. Other AAIs should be registered with SMPTE (see 7). 4.5 Destination and source address The destination and so
28、urce address represents the address of the devices within the connection according to the AAI. Sixteen bytes are allocated for both destination and source address with the following structure (see Fig. 8): Address: B7 to B0 B8 is even parity for B7 to B0 B9 is the complement of B8. When all 16 bytes
29、 are zero filled in accordance with AAI = “0000”, it should indicate the universal address to all devices connected to the interface. Also, it is the default condition when no destination and source address is required. 8 Rec. ITU-R BT.1381-3 4.6 Block type The block type should consist of one word
30、and is intended to indicate the segmentation of the payload. Either fixed block size or variable block size may be selected. B7 or B6 is the prefix to define the fixed block data structure as follows: B7 B6 Fixed block size without ECC: 0 0 Fixed block size with ECC: 0 1 Unassigned: 1 0 Reserved*: 1
31、 1 * The reserved prefix (B7, B6) = (1, 1) can only be used with the variable block size whose value is 01hfor B5 to B0. NOTE 1 The error correction code (ECC) will be determined individually in accordance with each application. 4.6.1 Fixed block size The possible segmentation of the fixed block siz
32、e and the values for B5 to B0 are shown in Table 1. Each data packet (data type + data block) should be placed one right after the other. B8 is even parity for B7 to B0 B9 is the complement of B8. Other block types should be registered with SMPTE (see 7). Rec. ITU-R BT.1381-3 9 TABLE 1 Fixed block s
33、ize Block type (B5-B0) Block size 270 Mbit/s 01h1 438 (1 437) words 1 block 02h719 (718) words 2 blocks 03h479 (478) words 3 blocks 04h359 (358) words 4 blocks 09hReserved 0Ah959 (958) words 1 block 0Bh639 (638) words 2 blocks 11h766 (765) words 1 block 12h383 (382) words 3 blocks 13h255 (254) words
34、 5 blocks 14h191 (190) words 7 blocks 21h5 (4) words 287 blocks 22h9 (8) words 159 blocks 23h13 (12) words 110 blocks 24h17 (16) words 84 blocks 25h33 (32) words 43 blocks 26h49 (48) words 29 blocks 27h65 (64) words 22 blocks 28h97 (96) words 14 blocks 29h129 (128) words 11 blocks 2Ah193 (192) words
35、 7 blocks 2Bh257 (256) words 5 blocks 2Ch385 (384) words 3 blocks 2Dh513 (512) words 2 blocks 2Eh609 (608) words 2 blocks 31h62 (61) words 23 blocks 32h153 (152) words 9 blocks 33h171 (170) words 8 blocks 34h177 (176) words 8 blocks 35h199 (198) words 7 blocks 36h256 (255) words 5 blocks 37h144 (143
36、) words 10 blocks 38h160 (159) words 9 blocks 10 Rec. ITU-R BT.1381-3 4.6.2 Variable block size The variable block size should have the following value: B7 B6 B5 B4 B3 B2 B1 B0 Variable block size: 1 1 0 0 0 0 0 1 B8 is even parity for B7 to B0 B9 is the complement of B8. With the variable block siz
37、e, any size of consecutive block data words is permitted. The next data packet can be either placed immediately after the previous one, or on the next line. For block lengths exceeding the payload of one line, code and AAI through reserved 0 within the header data should be repeated for each line th
38、at carries part of the block. 4.7 Payload CRC flag The payload CRC flag should consist of one word. The payload CRC flag is intended to indicate the presence of the payload CRC with the following values: B7 to B0 01h: The CRC should be inserted at the end of the payload 00h: The CRC should not be in
39、serted at the end of the payload, the space may be used for data 02h-FFh: Reserved B8 is even parity for B7 to B0 B9 is the complement of B8. 4.8 Header expansion reserved data The header expansion reserved data should be positioned after the CRC flag. The default value for the reserved data is 200h
40、. 4.9 Header CRC Following each ancillary data header, the header CRC should be inserted. The header CRC applies to the code through the reserved data for the entire ten bits. The generator polynomial for the header CRC should be the same as the line number CRC. 5 User data signal format User data m
41、ay be present on any line in the area between SAV and EAV. Some applications may constrain the use of certain lines. Although data may exist on any line, it should be noted that data can be corrupted during a switch. 5.1 Data block The data block should consist of either 8-bit words plus even parity
42、 or 9-bit words contained in B8 to B0. B9 of the user data word should be set to the complement of B8 (see Fig. 9). Rec. ITU-R BT.1381-3 11 5.2 Data block header Each data block should be preceded by the data block header. The data structure for the data block header should be as shown in Fig. 10 fo
43、r the fixed block size, and Fig. 11 for the variable block size. 12 Rec. ITU-R BT.1381-3 5.2.1 Separator and endcode The separator, endcode, and wordcount should be inserted, if the block type is identified as variable block size. Each data block starts with the separator and ends with the endcode.
44、The values of separator and endcode should be as follows: Separator: 309hB9 B8 B7 B6 B5 B4 B3 B2 B1 B0 1 1 0 0 0 0 1 0 0 1 Endcode: 30AhB9 B8 B7 B6 B5 B4 B3 B2 B1 B0 1 1 0 0 0 0 1 0 1 0 5.2.2 Wordcount The wordcount should consist of four words as shown in Fig. 12. The wordcount represents the numbe
45、r of data block words. The wordcount should be contained in C31 to C0, and should be interpreted as a single 32-bit binary value. EP1 is even parity for C7 to C0 EP2 is even parity for C15 to C8 EP3 is even parity for C23 to C16 EP4 is even parity for C31 to C24. Rec. ITU-R BT.1381-3 13 When no word
46、count is indicated, the value of the wordcount should be set to all zeros for C0 to C31. It is the intent of this standard that all receiving equipment should attempt to decode data, even if the wordcounts are expected but not present. 5.2.3 Data type1The data type should consist of one word. The da
47、ta type identifies the type of data stream and may have 256 different states (see Table 2). Data type: B7 to B0 B8 is even parity for B7 to B0 B9 is the complement of B8. Other data types should be registered with SMPTE (see 7). 1Designers should be aware that a previous revision of Recommendation I
48、TU-R BT.1381 permitted as an “invalid data type” code value 100h. Receiving equipment should be able to process invalid data type 100h. 14 Rec. ITU-R BT.1381-3 TABLE 2 Data type Type Description Type Description 101h102h203h104h205h206h107h108h209h20Ah10Bh20Ch10Dh10Eh20Fh110hSXV(1)CP-System CP-Pictu
49、re CP-Audio CP-Data 241h242h143h244h145h146h247h248h149h14Ah24Bh14Ch24Dh24Eh14Fh250hDV CAM-1 HD CAM D-11 211h212h113h214h115h116h217h218h119h11Ah21Bh11Ch21Dh21Eh11Fh120hSDTI-PF 151h152h253h154h255h256h157h158h259h25Ah15Bh25Ch15Dh15Eh25Fh260hMPEG-2 P/S(2)MPEG-2 T/S(3)Rec. ITU-R BT.1381-3 15 TABLE 2 (continued) Type Description Type Description 221h222h123h224h125h126h227h228h129h12Ah22Bh12Ch22Dh22Eh12Fh230hDVCPRO1/Digital S DVCPRO2 161h162h263h164
