1、BRITISH STANDARD BS EN 61595-2:1998 IEC 61595-2: 1997 Multichannel digital audio tape recorder (DATR), reel-to-reel system, for professional use Part 2: Format B The European Standard EN61595-2:1997 has the status of a British Standard ICS33.160.30BSEN 61595-2:1998 This British Standard, having been
2、 prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 March 1998 BSI 03-1999 ISBN 0 580 28424 7 National foreword This British Standard is the English language version of EN61595-2:1998. It is identica
3、l with IEC61595-2:1997. The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment, to Subcommittee EPL/100/2, Recording, which has the responsibility to: aid enquirers to understand the text; present to the responsible int
4、ernational/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request t
5、o its secretary. From 1 January 1997, all IEC publications have the number 60000 added to the old number. For instance, IEC27-1 has been renumbered as IEC60027-1. For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both system
6、s. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement international or European publications may
7、be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British St
8、andards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i andii, theEN title page, pages2 to24, an inside back cover and a
9、 back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSEN 61595-2:1998 BSI 03-1999 i Contents Page National forewor
10、d Inside front cover Foreword 2 Text of EN 61595-2 5ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61595-2 January 1998 ICS 33.160.30 Descriptors: Sound recording, digital recording, recording apparatus, tape recorders, magnetic tapes, dimensions, numeric codes, recording tracks, mecha
11、nical properties, electrical properties, recording characteristics, interchangeability English version Multichannel digital audio tape recorder (DATR), reel-to-reel system, for professional use Part 2: Format B (IEC 61595-2:1997) Systme denregistrement bande audionumrique multivoie (DATR), bobine bo
12、bine, usage professionnel Partie 2: Format B (CEI 61595-2:1997) Digitales Mehrkanal-Tonbandgert (DATR), Spulensystem fr Studioanwendungen Teil 2: Format B (IEC 61595-2:1997) This European Standard was approved by CENELEC on 1997-07-01. CENELEC members are bound to comply with the CEN/CENELEC Interna
13、l Regulations which stipulate the conditions for giving this European 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 memb
14、er. This European Standard exists in three official versions (English, 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
15、 members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Sta
16、ndardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1998 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61595-2:1998
17、 EEN61595-2:1998 BSI 03-1999 2 Foreword The text of document 100B/49/FDIS, future edition1 of IEC61595-2, prepared by SC100B, Recording, of IEC TC100, Audio, video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN61595-2 on 1997-07
18、-01. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given for information only. In this standard, Annex ZA is normative and Annex A is informative. Annex ZA has been added by CENELEC. Endorsement notice The te
19、xt of the International Standard IEC61595-2:1997 was approved by CENELEC as a European Standard without any modification. In the official version, for Annex A, Bibliography, the following notes have to be added for the standards indicated: IEC 60094 NOTEHarmonized as HD311 series and as EN60094 seri
20、es. IEC 60268-12 NOTEHarmonized, together with its amendment 1:1991, as EN60268-12:1995 (not modified). IEC 60958 NOTEHarmonized as EN60958:1990 (not modified). IEC 61120-1 NOTEHarmonized as EN61120-1:1993 (not modified). IEC 61120-2 NOTEHarmonized as EN 61120-2:1993 (not modified). IEC 61120-3 NOTE
21、Harmonized as EN61120-3:1993 (not modified). IEC 61120-5 NOTEHarmonized as EN61120-5:1995 (not modified). Contents Page Foreword 2 1 Scope 5 2 Normative references 5 3 Definitions 5 3.1 Data flow of a digital audio tape recorder 5 4 Digital encoding 7 4.1 Sampling frequency 7 4.2 Sampling timing 7 4
22、.3 Quantization 7 5 Tape speed 7 6 Tape width and number of digital audio channels 7 7 Tape winding 7 8 Reel and hub 7 9 Allocation and dimension of magnetic tracks 7 10 Assignment of magnetic tracks 7 11 Emphasis 11 12 Main track recording 11 12.1 Recording modulation method 11 12.1.1 Rule 1 (centr
23、e transitions) 12 12.1.2 Rule 2 (edge transitions) 12 12.2 Signal block structure 14 12.2.1 The word format 14 12.2.2 The block structure 14 12.2.3 The sync/control word 14 12.3 Track-to-channel assignment 16 12.4 Error protection method 18 12.4.1 Interleaving and parity sums 18 12.4.2 The CRC word
24、20 12.5 Recording and reproducing characteristics 20 12.5.1 Reference tape 20 13 Subtrack recording 21 13.1 Time code channel (time code track) 21 13.2 Auxiliary data channel 21 13.2.1 Reference track 21 13.2.2 Auxiliary data channel (auxiliary data track) 23 13.3 Auxiliary analogue channel (cue aud
25、io-1 track and/or cue audio-2 track) 23 13.4 Alignment of digital audio signals and subtrack signals 24 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1998-07-01 latest date by which the national standards
26、conflicting with the EN have to be withdrawn (dow) 1998-07-01EN61595-2:1998 BSI 03-1999 3 Page 13.4.1 Alignment of cue audio-1 and cue audio-2 track signals 24 13.4.2 Alignment of time code track signal 24 13.4.3 Alignment of reference track signal 24 Annex A (informative) Bibliography Inside back c
27、over Annex ZA (normative) Normative references to international publications with their corresponding European publications Inside back cover Figure 1 Data flow of the main audio channels of a DATR (digital audio tape recorder) 5 Figure 2 Recording channels of a DATR (digital audio tape recorder) 6
28、Figure 3 Reproducing channels of a DATR (digital audio tape recorder) 6 Figure 4 Track pattern for DATR on magnetic tape (28 tracks with 12,7 mm tape width) 8 Figure 5 Track pattern for DATR on magnetic tape (52 tracks with 12,7 mm tape width) 9 Figure 6 Track pattern for DATR on magnetic tape (103
29、tracks with 25,4mm tape width) 10 Figure 7 Emphasis characteristics 11 Figure 8 Rule 1 (centre transitions) 12 Figure 9 Rule 2 (edge transitions) case 1 12 Figure 10 Rule 2 (edge transitions) case 2 13 Figure 11 Rule 2 (edge transitions) case 3 13 Figure 12 Block address 14 Figure 13 The total signa
30、l block structure 15 Figure 14 Time diagram of the sync/control word 16 Figure 15 Computation of P and Q check words 19 Figure 16 Contents of one block, referred to one track input sequence 20 Figure 17 Range of CRC word 20 Figure 18 Biphase-mark coding rules 21 Figure 19 Word format of the referenc
31、e track word 22 Figure 20 The synchronization pattern and definition of the beginning of a sector 22 Figure 21 Control word 23 Figure 22 Effective computation range of the CRC word 23 Table 1 Tape width and number of digital audio channels 7 Page Table 2 Track assignment 7 Table 3 Block structure 14
32、 Table 4 24-channel version 16 Table 5 48-channel version 17 Table 6 96-channel version 184 blankEN61595-2:1998 BSI 03-1999 5 1 Scope This part of IEC61595 applies to 24 to 96 channel digital audio recording on 12,7mm or 25,4mm wide tape (hereinafter called tape), with stationary heads, for professi
33、onal use. It defines the mechanical and electrical characteristics necessary to ensure the interchangeability of programmes, recorded as digital audio signals on magnetic tape, in professional industries. 2 Normative references The following normative documents contain provisions which, through refe
34、rence in this text, constitute provisions of this part of IEC61595. At the time of publication, the editions indicated were valid. All normative documents are subject to revision, and parties to agreements based on this part of IEC61595 are encouraged to investigate the possibility of applying the m
35、ost recent editions of the normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 60461:1986, Time and control code for video tape recorders. IEC 61120-4:1992, Digital audio tape recorder reel-to-reel system, using 6,3mm magneti
36、c tape, for professional use Part 4: Magnetic tape properties: definitions and method of measurement. ITU-T V.41:1988, Code-independent error control system. 3 Definitions For the purpose of this part of IEC61595, the following definitions apply. 3.1 Data flow of a digital audio tape recorder Figure
37、 1 shows, within a block diagram, the main data flow of a DATR (digital audio tape recorder) Figure 2 shows the recording channels of a DATR Figure 3 shows the reproducing channels of a DATR Figure 1 Data flow of the main audio channels of a DATR (digital audio tape recorder)EN61595-2:1998 6 BSI 03-
38、1999 Figure 2 Recording channels of a DATR (digital audio tape recorder) Figure 3 Reproducing channels of a DATR (digital audio tape recorder)EN61595-2:1998 BSI 03-1999 7 4 Digital encoding 4.1 Sampling frequency The sampling frequency shall be 48kHz, and the accuracy of the sampling frequency at en
39、coding shall be 50 10 6 . 4.2 Sampling timing It is recommended that all channels are sampled simultaneously. 4.3 Quantization Each audio sample shall be quantized uniformly and be expressed in 16 bits, 2 s complement code. Positive numbers correspond to positive analogue voltages at the input. 5 Ta
40、pe speed The tape speed shall be nominal 76,20cm/s. The tolerance on tape speed shall be within 0,2%. 6 Tape width and number of digital audio channels The tape width shall be mm (nominal 25,4mm) ormm (nominal 12,7mm). Table 1 shows tapewidth and number of digital audio channels. Table 1 Tape width
41、and number of digital audio channels 7 Tape winding The magnetic coating faces the centre of the reel. 8 Reel and hub Under consideration. 9 Allocation and dimension of magnetic tracks The Figure 4, Figure 5 and Figure 6 show the track allocations on magnetic tape. 10 Assignment of magnetic tracks I
42、f the tape moves from the left to right with the magnetic coating facing away from the observer and with the leader to the right, the bottom track is designated track 1, the next upper track is designated track 2 and so on. Table 2 shows the assignment of magnetic tracks. Table 2 Track assignment It
43、ems Contents Tape width (mm) 25,4 12,7 Number of audio channels 96 48 24 Main 96 48 24 Number of tracks Sub 7 4 4 Total 103 52 28 Main tracks/audio channels 1/1 1/1 1/1 Track number Tape width (mm) 25,4 12,7 Main Digital audio 499 225, 2851 213; 1627 Time code 3 26 14 Type of track Sub Cue audio-1 1
44、 1 1 Cue audio-2 103 52 28 Reference 101 27 15 Auxiliary data 2, 100, 102 1 a 1 a a Refer to 13.2.2. 25,37 0 0,03 1266 0 002 , ,EN61595-2:1998 8 BSI 03-1999 Figure 4 Track pattern for DATR on magnetic tape (28 tracks with 12,7 mm tape width)EN61595-2:1998 BSI 03-1999 9 Figure 5 Track pattern for DAT
45、R on magnetic tape (52 tracks with 12,7mm tape width)EN61595-2:1998 10 BSI 03-1999 Figure 6 Track pattern for DATR on magnetic tape (103 tracks with 25,4mm tape width)EN61595-2:1998 BSI 03-1999 11 11 Emphasis In general, the use of emphasis is not recommended. If pre-emphasis is applied, the emphasi
46、s shall be used with the characteristics of a first order pre-emphasis, as shown in Figure 7. 12 Main track recording 12.1 Recording modulation method In this subclause, the modulation of a binary data sequence (“incoming data”) into a record signal waveform (“output waveform”) is specified. Next, a
47、 synchronization pattern violating the modulation rules is defined. The data to be recorded on the main tracks are first channel-coded. A run-length-limited code called HDM-1 is used, which is not d.c. free. The output waveform is defined by two cells for each input data bit. Only transitions in the
48、 output waveform are defined; the output data is independent of waveform polarity. Rules for generating a pair of output waveform cells for each input bit are defined in the following formulation and bit to waveform transitions are defined in rules 1 and 2. Formulation for bit to waveform modulation
49、: X i= input bit delayed by i bit clocks T j= output waveform cell delayed by j cell clocks EDGE: timing variable, 0 at centre, 1 at edge of bit interval Figure 7 Emphasis characteristicsEN61595-2:1998 12 BSI 03-1999 12.1.1 Rule 1 (centre transitions) A data bit sequence of “01” always leads to a centre transition in the middle of the “1” bit. Thus, the presence of a bit pattern “01” in the data bit sequence always enforces a centre transition in the cell
