1、BRITISH STANDARD BS EN 61883-7:2003 Consumer audio/video equipment Digital interface Part 7: Transmission of ITU-R BO.1294 System B The European Standard EN 61883-7:2003 has the status of a British Standard ICS 33.160.01; 35.200 BS EN 61883-7:2003 This British Standard was published under the author
2、ity of the Standards Policy and Strategy Committee on 15 May 2003 BSI 15 May 2003 ISBN 0 580 41827 8 National foreword This British Standard is the official English language version of EN 61883-7:2003. It is identical with IEC 61883-7:2003. The UK participation in its preparation was entrusted to Te
3、chnical Committee EPL/100, Audio, video and multimedia systems and equipment, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publicati
4、ons referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessa
5、ry provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpr
6、etation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 14, an inside back cover and a bac
7、k cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 61883-7 NORME EUROPENNE EUROPISCHE NORM April 2003 CENELEC European Committee for Electrotechnical Standardization Co
8、mit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61883-7:2003 E ICS 33.1
9、60.01; 35.200 English version Consumer audio/video equipment Digital interface Part 7: Transmission of ITU-R BO.1294 System B (IEC 61883-7:2003) Matriel audio/vido grand public - Interface numrique Partie 7: Transmission du Systme B de lUIT-R BO.1294 (CEI 61883-7:2003) Audio/Video-Gerte der Unterhal
10、tungselektronik Digitale Schnittstelle Teil 7: bertragung nach Rec. ITU-R BO.1294 System B (IEC 61883-7:2003) This European Standard was approved by CENELEC on 2003-03-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Eur
11、opean Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (En
12、glish, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria
13、, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. Foreword The text of document 100/558/FDIS, future edition 1 of IEC 61883-7, prepared by
14、technical area 4, Digital system interfaces, of IEC TC 100, Audio, video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61883-7 on 2003-03-01. The following dates were fixed: latest date by which the EN has to be implemented at
15、national level by publication of an identical national standard or by endorsement (dop) 2003-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2006-03-01 Annexes designated “normative“ are part of the body of the standard. In this standard, annexes
16、A and ZA are normative. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61883-7:2003 was approved by CENELEC as a European Standard without any modification. _ Page2 EN618837:2003 CONTENTS 1 Scope.4 2 Normative references.4 3 Terms, definitions and
17、 abbreviations 4 3.1 Terms and definitions 4 3.2 Abbreviations5 4 DSS transport stream .5 5 Construction of an IEEE 1394 packet .7 5.1 Source packets.7 5.2 Isochronous packets.9 6 Transmission of isochronous packets .10 6.1 Late packets10 Annex A (normative) Buffer size for DSS transmission11 Annex
18、ZA (normative) Normative references to international publications with their corresponding European publications .14 Figure 1 Steps in the transmission of transport stream.6 Figure 2 DSS stream processing block diagram .6 Figure 3 Structure of a source packet 7 Figure 4 DSS packet header structure .
19、7 Figure 5 Structure of the source packet header8 Figure 6 FDF structure.10 Table 1 Fields in the DSS packet header .8 Table 2 Fields in the CIP header9 Table A.1 Buffer for jitter example12 Table A.2 Buffer for MPEG smoothing example12 Page3 EN618837:2003 CONSUMER AUDIO/VIDEO EQUIPMENT DIGITAL INTE
20、RFACE Part 7: Transmission of ITU-R BO.1294 System B 1 Scope This specification defines packetization and transmission for transport streams of ITU-R BO.1294 system B (DirecTV system/DSS) over the IEEE 1394 Serial Bus. 2 Normative references The following referenced documents are indispensable for t
21、he application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 61883-1, Consumer audio/video equipment Digital interface Part 1: General ITU-R BO.1294:1997, Common fu
22、nctional requirements for the reception of digital multi- programme television emissions by satellites operating in the 11/12 GHz frequency range 1IEEE 1394:1995, Standard for a High Performance Serial Bus IEEE 1394a:2000, Standard for a High Performance Serial Bus Amendment 1 3 Terms, definitions a
23、nd abbreviations For the purposes of this part of IEC 61883, the following terms and definitions apply. 3.1 Terms and definitions For the purposes of this part of IEC 61883, the following terms and definitions apply. 3.1.1 byte eight bits of data, used as a synonym for octet NOTE The symbol for byte
24、 is B. 3.1.2 CSR architecture convenient abbreviation of the following reference: ISO/IEC 13213:1994, Information technology Microprocessor systems Control and status register (CSR) architecture for microcomputer buses 3.1.3 quadlet four bytes of data 1In this document, the name “DSS” is used instea
25、d of ITU-R BO.1294 system B. Page4 EN618837:2003 3.2 Abbreviations For the purpose of this part of IEC 61883, the following abbreviations used in IEEE 1394 apply: AV/C Audio Video Control CIP Common Isochronous Packet CTR Cycle Time Register HD High Definition IEEE The Institute of Electrical and El
26、ectronics Engineers, Inc. MPEG Motion Picture Expert Group TSP Transport Stream Package 4 DSS transport stream A DSS transport stream consists of transport stream packets with a length of 130 B. NOTE Refer to Annex 1 of ITU-R BO.1294: 1997 for more information. A stream may contain several programs.
27、 In Figure 1, an example is given of a transport stream, which consists of several programs. Often, only one or a few programs need to be transmitted. If a program selection is carried out, then only those transport stream packets from that particular transport stream are transmitted. In this situat
28、ion, the occupied bandwidth on the IEEE 1394 interface can be reduced. Reduction of the bit rate is carried in a smoothing buffer. As a result of the smoothing operation, the transport stream packets will be shifted in time. The transport stream packets at the output of the smoothing buffer are tran
29、smitted over the IEEE 1394 interface. During transmission, this interface will introduce some jitter on the arrival time of the transport stream packets in the receiver. In the DSS transport stream, there are strong requirements on the timing of the transport stream packets. The jitter introduced by
30、 the both the smoothing buffer and the transmitter of the interface has to be compensated. This is done by adding a time stamp to the transport stream packets: at the moment it arrives at the input of the smoothing buffer; or at the input of the digital interface, if smoothing is not applied. The re
31、ceiver of the interface contains a receiver buffer, which compensates for the introduced jitter. Page5 EN618837:2003 A B C A A B C D A D B a) b) c) d) e) f) A A A A DSS packet Source packet Overall delay (offset in timestamp)a) Complete transport stream with multiplex of programs (A,B,C,D) b) Transp
32、ort stream of the selected program A with DSS packet header (=DSS source packets) c) Source packets with source packet header d) Source packets at the output of the smoothing buffer e) Source packets at the input of the 1394 receiver f) Reconstructed timing for the transport stream NOTE The clock fr
33、equency for transferring the bytes of a transport stream packet may be different in every situation Figure 1 Steps in the transmission of transport stream Figure 2 shows how the DSS stream is processed between the original multiplex signal, the IEEE 1394 interface and the decoder. Transmitter Smooth
34、ing buffer Receiving buffer Timing recovery (de- smoother) 1394 DSS and source packet headers added Smoothing buffer evens the interval between packets Arbitrate for bus and transmit data Re- construction of original timing Original multiplex signal Demux Add headers a) c) d) e) T-STD f)Figure 2 DSS
35、 stream processing block diagram IEC 3100/02 IEC 3101/02 Page6 EN618837:2003 5 Construction of an IEEE 1394 packet 5.1 Source packets 5.1.1 Structure of a source packet The length of the source packet is 140 B as shown in Figure 3. The source packet consists of one DSS transport stream packet with a
36、 length of 130 B and a DSS packet header of 10 B. The source packet header is additionally added before transmission to the smoothing buffer. The source packet header contains a time stamp. Source packet header (4 B) DSS packet header (10 B) DSS source packet (140 B) DSS transport stream packet (130
37、 B)Figure 3 Structure of a source packet 5.1.2 DSS packet header Figure 4 shows the structure of a DSS packet header. m s b l s b MSB SIF System Clock Count (23 bit) EF Reserved (0000000 2) Reserved byte 0 (0016) Reserved byte 1 (0016) Reserved byte 2 (0016) Reserved byte 3 (0016) Reserved byte 4 (0
38、016) LSB Reserved byte 5 (0016) Figure 4 DSS packet header structure IEC 3102/02 IEC 3103/02 Page7 EN618837:2003 Table 1 shows the DSS packet header components. Table 1 Fields in the DSS packet header Field Definition SIF System clock count Invalid Flag (1: invalid, 0: valid) System clock count (23
39、bit) A 23 bit field that is set to the lowest 23 bit of the 27 MHz clock counter, which is synchronized with MPEG system clock. The value of this counter may be different from the byte time stamp counter used to generate the byte time stamp in the auxiliary data packet (defined in 4.1 of Appendix 1
40、to Annex 1 of ITU-R BO.1294: 1997. EF Error Flag (1: Error, 0: no Error) Set to value 1 when the associated transport stream packet is erroneous The system clock count is used by bit stream recorders, like D-VHS, to lock its system clock phase to the source stream without needing to look into the DS
41、S transport stream packet for clock information. If a stream contains video and/or audio application packets, then the stream shall contain packets with a valid system clock count. The maximum interval between valid system clock counts (or “ticks”) shall be 200 ms. Therefore many audio and video pac
42、kets in between may not contain a valid system clock count. If a stream does not contain video or audio application packets, then the system clock count is not required. 5.1.3 Source packet header Figure 5 shows the structure of the source packet header. m s b l s b MSB Reserved Cycle_count (13 bit)
43、 Cycle_offset (12 bit) LSB Figure 5 Structure of the source packet header The reserved bits are zero. The cycle_count and cycle_offset fields represent a time stamp. The time stamp is used by isochronous data receivers for reconstructing a correct timing of the transport stream packets at their outp
44、ut. The time stamp indicates the intended delivery time of the first bit/byte of the transport stream packets from the receiver output to the T-STD (Transport Stream Target Decoder). The time stamp represents the 25 bit of the IEEE 1394 CYCLE_TIME register (CTR) at the moment the first bit/byte of t
45、he transport stream packet arrives from the application, plus an offset which is equal to the constant overall delay of the transport stream packet between the moment of arriving (of the first bit) and the moment the transport stream packet (first bit) is delivered by the receiver to the application
46、. IEC 3104/02 Page8 EN618837:2003 5.1.4 Fractions A source packet is split into 4 data blocks with a length of 9 quadlets. Zero or more data blocks are packed in an IEEE 1394 isochronous packet. A receiver of the isochronous packets collects the data blocks of one source packet and combines them in
47、order to reconstruct the source packet before sending this source packet to the application. There are restrictions on the transmission of fractions (see 5.2.2). 5.2 Isochronous packets 5.2.1 CIP header for the DSS transport stream The structure of the CIP header for DSS transport stream conforms to
48、 the two quadlet CIP header format explained in IEC 61883-1, 6.2.1. Table 2 shows the values of the CIP header components. Table 2 Fields in the CIP header Field Value Description SID . Depends on configuration DBS 00001001 2 9 quadlets FN 10 2 4 data blocks in one source packet QPC 000 2 No padding
49、 SPH 1 Source packet header is present DBC 0 . 255 See 5.2.2 FMT 100001 2 Format type of DSS (ITU-R BO.1294 System B) FDF . See 5.2.3 5.2.2 DBC values The first data block of a source packet (data block containing the source packet header) corresponds to a DBC value from which the two LSBs are 00 2 . An isochronous packet contains 0, 1, or 2 data blocks, or an integer number of source packe
