BS EN 61937-12-2010 Digital audio Interface for nnon-linear PCM encoded audio nbitstreams applying IEC 60958 nPart 12 Non-linear PCM bitstreams according nto the DRA formats《数字音频 .pdf

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1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationDigital audio Interface for non-linear PCM encoded audiobitstreams applying IEC 60958Part 12: Non-linear PCM bitstreams according to the DRA formatsBS EN 61937-12:2010National fo

2、rewordThis British Standard is the UK implementation of EN 61937-12:2010. It isidentical to IEC 61937-12:2010.The UK participation in its preparation was entrusted to Technical CommitteeEPL/100, Audio, video and multimedia systems and equipment.A list of organizations represented on this committee c

3、an be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2010ISBN 978 0 580 72209 7ICS 33.160.30; 33.170Compliance with a British Standard cannot confer immunity fromlegal

4、obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 31 August 2010.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 61937-12:2010EUROPEAN STANDARD EN 61937-12 NORME EUROPENNE EUROPISCHE NORM June 2010

5、 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2010 CENELEC - All rights of exploitation in any form and by any means reserved wor

6、ldwide for CENELEC members. Ref. No. EN 61937-12:2010 E ICS 33.160.30; 33.170 English version Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 12: Non-linear PCM bitstreams according to the DRA formats (IEC 61937-12:2010) Audionumrique - Interface pour

7、les flux de bits audio codage MIC non linaire conformment la CEI 60958 - Partie 12 : Flux de bits codage MIC non linaire conforme au format DRA (CEI 61937-12:2010) Digitalton Schnittstelle fr nichtlinear-PCM-codierte Audio-Bitstrme unter Verwendung von IEC 60958 Teil 12: Nichtlineare PCM-Bitstrme en

8、tsprechend DRA-Formaten (IEC 61937-12:2010) This European Standard was approved by CENELEC on 2010-06-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alter

9、ation. 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 (English, French, German). A version in any other language made by tr

10、anslation 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, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark,

11、 Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 61937-12:2010EN 61937-12:2010 - 2 - Foreword The text o

12、f document 100/1578/CDV, future edition 1 of IEC 61937-12, prepared by 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 61937-12 on 2010-06-01. Attention is drawn to the possibility that some of the elemen

13、ts of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard o

14、r by endorsement (dop) 2011-03-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2013-06-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61937-12:2010 was approved by CENELEC as a European Standard

15、 without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60958-1 NOTE Harmonized as EN 60958-1. IEC 60958-3 NOTE Harmonized as EN 60958-3. _ BS EN 61937-12:2010- 3 - EN 61937-12:2010 Annex ZA (normative) Normative ref

16、erences to international publications with their corresponding European publications The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document

17、(including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60958 Series Digital audio interface EN 60958 Series IEC 61937 Series Digital audio - Interface

18、for non-linear PCM encoded audio bitstreams applying IEC 60958 EN 61937 Series IEC 61937-1 2007 Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 1: General EN 61937-1 2007 IEC 61937-2 - Digital audio - Interface for non-linear PCM encoded audio bitstrea

19、ms applying IEC 60958 - Part 2: Burst-info EN 61937-2 - BS EN 61937-12:2010 2 61937-12 IEC:2010(E) CONTENTS 1 Scope.5 2 Normative references .5 3 Terms and definitions .5 3.1 Terms and definitions 5 3.2 Abbreviations 6 3.3 Presentation convention 6 4 DRA burst-info6 5 Format of DRA data-bursts.6 5.1

20、 General .6 5.2 Pause data-burst.7 5.3 Audio data-bursts 7 5.3.1 DRA condition .7 5.3.2 DRA half-rate low sampling frequency condition 9 5.3.3 DRA quarter-rate low sampling frequency condition.11 Bibliography14 Figure 1 DRA data-burst 8 Figure 2 Latency of DRA decoding.9 Figure 3 DRA data-burst half

21、-rate low sampling frequency.10 Figure 4 Latency of DRA decoding half-rate low sampling frequency .11 Figure 5 DRA data-burst quarter-rate low sampling frequency12 Figure 6 Latency of DRA decoding quarter-rate low sampling frequency 13 Table 1 Fields of burst-info 6 Table 2 Data-type-dependent infor

22、mation for data-type DRA7 Table 3 Repetition period of pause data-bursts 7 BS EN 61937-12:201061937-12 IEC:2010(E) 5 DIGITAL AUDIO INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO BITSTREAMS APPLYING IEC 60958 Part 12: Non-linear PCM bitstreams according to the DRA formats 1 Scope This part of IEC 61937 s

23、pecifies the method for IEC 60958 to convey non-linear PCM bitstreams encoded in accordance with the DRA formats. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated refere

24、nces, the latest edition of the referenced document (including any amendments) applies. IEC 60958 (all parts), Digital audio interface IEC 61937 (all parts), Digital audio Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 IEC 61937-1:2007, Digital audio Interface for non-linea

25、r PCM encoded audio bitstreams applying IEC 60958 Part 1: General IEC 61937-2, Digital audio Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 Part 2: Burst-info 3 Terms and definitions For the purposes of this document, the following terms, definitions, abbreviations and pres

26、entation conventions apply. 3.1 Terms and definitions 3.1.1 sub data-type type of payload of the data-burst for use with the specified data-type 3.1.2 latency delay time of an external audio decoder to decode a DRA data-burst NOTE It is defined as the sum of two values of the receiving delay time an

27、d the decoding delay time. 3.1.3 length code indicates the length of the data-burst payload in bits or bytes NOTE See Table 3 of IEC 61937-1. BS EN 61937-12:2010 6 61937-12 IEC:2010(E) 3.2 Abbreviations DRA Digital Rise Audio 3.3 Presentation convention 012 Value “01” in binary format 4 DRA burst-in

28、fo The general coding method of the bitstream and data-burst is according to IEC 61937-1 and IEC 61937-2. The 16-bit burst-info (Pc) is defined in Table 1. Table 1 Fields of burst-info Bits of Pc Value Contents Reference point R Repetition period of data-burst in IEC 60958 frames Data-type 0-22 In a

29、ccordance with IEC 61937-2 23 DRA or other MPEG applications according to IEC 61937-2, depending on sub data-type 0 4 24-31 In accordance with IEC 61937-2 Subdata-type 002-102In accordance with IEC 61937-2 5 6 112DRA Bit 0 of Pa Depending on bits 8-9 of Pc 7 In accordance with IEC 61937-1 8 12 data-

30、type-dependent information for data-type DRA 13 15 In accordance with IEC 61937-1 5 Format of DRA data-bursts 5.1 General This clause specifies the audio data-bursts of DRA. Specific properties such as reference points, repetition period, the method of filling stream gaps, and decoding latency are s

31、pecified for the DRA data-type. BS EN 61937-12:201061937-12 IEC:2010(E) 7 The decoding latency (or delay), indicated for the DRA data-type, should be used by the transmitter to schedule data-bursts as necessary to establish synchronization between the video and the decoded audio. The data-type-depen

32、dent information assignment for DRA is given in Table 2. As shown in Table 2, bits 8-9 of Pc are used to identify the relation between the sampling frequencies of DRA and the IEC 60958 frame rate. Table 2 Data-type-dependent information for data-type DRA Bits of Pc LSB.MSB Value Contents Repetition

33、period of data-burst in IEC 60958 frames 002DRA 1 024 012DRA half-rate low sampling frequency 2 048 102DRA quarter-rate low sampling frequency 4 096 8 9 112Reserved - 0002Reserved, shall be used until further definition 10 12 0012 1112Reserved, shall not be used until further definition 5.2 Pause da

34、ta-burst The pause data-burst for DRA is given in Table 3. Table 3 Repetition period of pause data-bursts Repetition period of pause data-burst Type of audio data-burst indicated by bits 8-9 of Pc Mandatory Recommended DRA - 32 IEC 60958 frames DRA half-rate low sampling frequency - 64 IEC 60958 fra

35、mes DRA quarter-rate low sampling frequency - 128 IEC 60958 frames 5.3 Audio data-bursts 5.3.1 DRA condition 5.3.1.1 Data for DRA The streams of the data-bursts of DRA consist of sequences of DRA frames. The data-type and sub-data-type of a DRA data-burst are 23 and 3 respectively with the bits 8-9

36、of Pc equal to 002. The data-burst is headed with a burst-preamble, followed by the burst-payload, and stuffed with stuffing bits. The burst-payload of each data-burst of DRA data shall contain one BS EN 61937-12:2010 8 61937-12 IEC:2010(E) complete DRA frame and represents 1 024 samples for each en

37、coded channel. The length of the DRA data-burst depends on the encoded bit rate, which determines the DRA frame length. The specification of the DRA frame can be found in GB/T 22726-2008. The units of length-code (Pd) shall be in bytes. Pa Pb Pc PdDRAburst_payloadPa Pb Pc PdDRAburst_payloadRegular r

38、ate of the DRARepetition period of the burstDRA frameDRA frameBit 0 of PaStuffingBit 0 of PaFigure 1 DRA data-burst The reference point of a DRA data-burst is bit 0 of Pa and occurs exactly once every 1 024 sampling periods. The data-burst containing DRA frames shall occur at a regular rate, with th

39、e reference point of each DRA data-burst beginning 1 024 IEC 60958 frames after the reference point of the preceding DRA data-burst of the same bitstream number. It is recommended that pause data-bursts are used to fill stream gaps in the DRA bitstream as described in IEC 61937-1, and that pause dat

40、a-bursts be transmitted with a repetition period of 32 IEC 60958 frames, except when other repetition periods are necessary to fill the precise stream-gap length, which may not be a multiple of 32 IEC 60958 frames, or to meet the requirement on burst spacing of IEC 61937. When a stream gap in a DRA

41、stream is filled by a sequence of pause data-bursts, the Pa of the first pause data-burst shall be located at 1 024 sampling periods following the Pa of the previous DRA frame. It is recommended that the sequence(s) of pause data-bursts which fill the stream gap should continue from this point up to

42、 (as close as possible to, considering the 32 IEC 60958 frame length of the pause data-burst) the Pa of the DRA data-burst which follows the stream gap. The gap-length parameter contained in the pause data-burst is intended to be interpreted by the DRA decoder as an indication of the number of decod

43、ed PCM samples which are missing, due to the resulting audio gap. 5.3.1.2 Latency of DRA decoding The latency of an external audio decoder to decode DRA is defined as the sum of the receiving delay time and the decoding delay time. IEC 1059/10 BS EN 61937-12:201061937-12 IEC:2010(E) 9 Figure 2 Laten

44、cy of DRA decoding EXAMPLE The receiving delay time to receive a whole data-burst with maximum length is calculated as follows. The length of preamble is 64 bits. The maximum length of whole data payload is 4 096 bit for a maximum bit rate of 192 kbit/s. In this case, the maximum length of data-burs

45、ts is 4 160 bits. The receiving delay is 2,708 ms (4 160 2/48/64) at 48 kHz sampling frequency. The decoding delay is 21,333 ms, corresponding to one DRA frame. Hence, the latency of DRA decoding is approximately 24,041 ms. The absolute maximum length of the data-burst is calculated as follows. Each

46、 data-burst contains a minimum of 4 stuffing 16-bit words. The repetition period of data-burst is 1 024 IEC 60958 frames. Therefore, the maximum length of data-burst leads as follows: 1 024 samples 2 channels 16 bits 4 words 16 bits = 32 704 bits The receiving delay time is 21,292 ms (32 704 2/48/64

47、) at 48 kHz sampling frequency, which leads to the absolute maximum DRA decoding latency of 42,625 ms with the decoding delay 21,333 ms as above. 5.3.2 DRA half-rate low sampling frequency condition 5.3.2.1 Data for DRA half-rate low sampling frequency The streams of the data-bursts for DRA half-rat

48、e low sampling frequency consist of sequences of DRA half-rate low sampling frequency frames. The data-type and sub-data-type of a DRA data-burst are 23 and 3 respectively with the bits 8-9 of Pc equal to 012. The data-burst is headed with a burst-preamble, followed by the burst-payload, and stuffed

49、 with stuffing bits. The burst-payload of each data-burst of DRA half-rate low sampling frequency data shall contain one complete DRA half-rate low sampling frequency frame and represents 2 048 samples for each encoded channel. In the context of this standard, terms relating to “half-rate low sampling frequency” mean the sampling frequency of the IEC 60958 frame (i.e., IEC 60958 frame rate) increases to 2 original s