1、 ETSI TS 103 466 V1.1.1 (2016-10) Digital Audio Broadcasting (DAB); DAB audio coding (MPEG Layer II) TECHNICAL SPECIFICATION ETSI ETSI TS 103 466 V1.1.1 (2016-10)2 Reference DTS/JTC-DAB-81 Keywords audio, broadcasting, coding, DAB, digital ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex -
2、 FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present document can be downloaded from: http:/www.etsi.org/standards-search The present document may b
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6、uced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm except as authorized by written permission of ETSI. The content of the PDF version shall not be modified without the written authorization of ETSI. The copyright and the foregoing restriction
7、 extend to reproduction in all media. European Telecommunications Standards Institute 2016. European Broadcasting Union 2016. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE are Trade Marks of ETSI re
8、gistered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TS 103 466 V1.1.1 (2016-10)3 Contents Intellectual Property Rights 5g3Foreword . 5g3Modal verbs terminology 5g31 Scope 6g32 Ref
9、erences 6g32.1 Normative references . 6g32.2 Informative references 6g33 Definitions, abbreviations and mathematical symbols . 6g33.1 Definitions 6g33.2 Abbreviations . 9g33.3 Mathematical symbols 9g33.3.1 Arithmetic operators . 9g33.3.2 Logical and set operators 10g33.3.3 Functions 10g33.3.4 Consta
10、nts 10g33.4 C-language mathematical symbols . 10g33.4.1 Arithmetic operators . 10g33.4.2 Logical operators 10g33.4.3 Relational operators 11g33.4.4 Assignment . 11g33.4.5 Mnemonics . 11g33.4.6 Method of describing bit stream syntax 11g33.5 Convention . 12g34 Introduction 13g35 DAB audio coding 13g35
11、.1 Introduction 13g35.2 Audio encoding 14g35.2.0 General 14g35.2.1 Analysis sub-band filter 14g35.2.2 Scale Factor calculation 16g35.2.3 Coding of Scale Factors 16g35.2.4 Coding of Scale Factor Selection Information 17g35.2.5 Psychoacoustic model . 18g35.2.6 Bit allocation . 18g35.2.7 Bit allocation
12、 coding . 19g35.2.8 Quantization and coding of sub-band samples 21g35.2.9 Formatting of the audio bit stream 23g35.3 Semantics of the audio bit stream . 24g35.3.1 MPEG Audio Layer II bit stream 24g35.3.1.1 Audio sequence . 24g35.3.1.2 Audio frame 24g35.3.1.3 Audio frame header . 24g35.3.1.4 Error ch
13、eck 27g35.3.1.5 Audio data . 27g35.3.1.6 Ancillary data 28g35.3.2 DAB audio bit stream . 28g35.3.2.0 Introduction . 28g35.3.2.1 DAB audio sequence . 28g35.3.2.2 DAB audio frame 28g35.3.2.3 DAB audio frame header 29g35.3.2.4 Error check 29g35.3.2.5 Audio data . 29g35.3.2.6 Audio stuffing bits 29g35.3
14、.2.7 Extended Programme Associated Data (X-PAD) . 29g3ETSI ETSI TS 103 466 V1.1.1 (2016-10)4 5.3.2.8 Scale Factor Error Check (ScF-CRC) . 30g35.3.2.9 Fixed Programme Associated Data (F-PAD) 30g35.4 Audio bit stream syntax 32g35.4.0 Introduction. 32g35.4.1 ISO/IEC 11172-3 and ISO/IEC 13818-3 Layer II
15、 bit stream syntax 32g35.4.1.0 General 32g35.4.1.1 Audio sequence . 32g35.4.1.2 Audio frame 32g37.3.1.3 Header . 32g35.4.1.4 Error check 33g35.4.1.5 Audio data . 33g35.4.1.6 Ancillary data 34g35.4.2 DAB audio bit stream syntax 34g35.4.2.0 General 34g35.4.2.1 DAB audio sequence . 34g35.4.2.2 DAB audi
16、o frame 34g35.4.2.3 DAB audio frame header 34g35.4.2.4 Error check 34g35.4.2.5 Audio data . 34g35.4.2.6 Audio stuffing bits 35g35.4.2.7 Extended Programme Associated Data . 35g35.4.2.8 Scale factor error check . 35g35.4.2.9 Fixed Programme Associated Data . 35g35.5 Programme Associated Data (PAD) .
17、36g35.5.1 Coding 36g35.5.2 Transport . 36g35.5.3 Dynamic Range Control data 37g3Annex A (informative): Main characteristics of the audio coding system 38g3A.1 Audio signal characteristics 38g3A.2 Audio coding characteristics 38g3A.3 Audio associated data characteristics . 39g3Annex B (normative): Au
18、dio decoding . 40g3B.1 General . 40g3B.2 CRC check for audio side information . 40g3B.3 CRC check for Scale Factors 40g3B.4 Decoding of the MPEG Audio Layer II bit stream 41g3Annex C (informative): Audio encoding . 42g3C.1 Analysis sub-band filter 42g3C.2 Psychoacoustic model 45g3C.3 Bit allocation
19、procedure . 53g3C.4 Bit sensitivity to errors . 55g3C.5 Error concealment 56g3C.6 Joint stereo coding 56g3History 59g3ETSI ETSI TS 103 466 V1.1.1 (2016-10)5 Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pe
20、rtaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secr
21、etariat. Latest updates are available on the ETSI Web server (https:/ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates
22、on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Specification (TS) has been produced by Joint Technical Committee (JTC) Broadcast of the European Broadcasting Union (EBU), Comit Europen de Normalisation ELECtrotechnique (CENELEC
23、) and the European Telecommunications Standards Institute (ETSI). NOTE 1: The EBU/ETSI JTC Broadcast was established in 1990 to co-ordinate the drafting of standards in the specific field of broadcasting and related fields. Since 1995 the JTC Broadcast became a tripartite body by including in the Me
24、morandum of Understanding also CENELEC, which is responsible for the standardization of radio and television receivers. The EBU is a professional association of broadcasting organizations whose work includes the co-ordination of its members activities in the technical, legal, programme-making and pr
25、ogramme-exchange domains. The EBU has active members in about 60 countries in the European broadcasting area; its headquarters is in Geneva. European Broadcasting Union CH-1218 GRAND SACONNEX (Geneva) Switzerland Tel: +41 22 717 21 11 Fax: +41 22 717 24 81 The Eureka Project 147 was established in 1
26、987, with funding from the European Commission, to develop a system for the broadcasting of audio and data to fixed, portable or mobile receivers. Their work resulted in the publication of European Standard, ETSI EN 300 401 1, for DAB (see note 2) which now has worldwide acceptance. NOTE 2: DAB is a
27、 registered trademark owned by one of the Eureka Project 147 partners. The DAB family of standards is supported by WorldDAB, an organization with members drawn from broadcasting organizations and telecommunication providers together with companies from the professional and consumer electronics indus
28、try. Modal verbs terminology In the present document “shall“, “shall not“, “should“, “should not“, “may“, “need not“, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). “must“ and “must n
29、ot“ are NOT allowed in ETSI deliverables except when used in direct citation. ETSI ETSI TS 103 466 V1.1.1 (2016-10)6 1 Scope The present document defines the method to code and transmit audio services using the MPEG Layer II audio coder for Digital Audio Broadcasting (DAB) (ETSI EN 300 401 1) and de
30、tails the necessary mandatory requirements for decoders. The permitted audio modes and the data protection and encapsulation are detailed. This audio coding scheme permits the full use of the PAD channel for carrying dynamic labels and user applications. 2 References 2.1 Normative references Referen
31、ces are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the referenced document (including any amendments) applies. Referenced docu
32、ments which are not found to be publicly available in the expected location might be found at https:/docbox.etsi.org/Reference/. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The following referenced document
33、s are necessary for the application of the present document. 1 ETSI EN 300 401 (V2.1.1): “Radio Broadcasting Systems; Digital Audio Broadcasting (DAB) to mobile, portable and fixed receivers“. 2 ISO/IEC 11172-3 (1993): “Information technology - Coding of moving pictures and associated audio for digi
34、tal storage media at up to 1,5 Mbit/s - Part 3: Audio“. 3 IEC 60958 (all parts): “Digital audio interface“. 4 ISO/IEC 13818-3: “Information technology - Generic coding of moving pictures and associated audio information - Part 3: Audio“. 2.2 Informative references References are either specific (ide
35、ntified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the referenced document (including any amendments) applies. NOTE: While any hyperlinks included in this
36、 clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. Not applicable. 3 Definitions, abbreviati
37、ons and mathematical symbols 3.1 Definitions For the purposes of the present document, the terms and definitions given in ETSI EN 300 401 1 and the following apply: alias component: mirrored signal component resulting from sub-Nyquist sampling ETSI ETSI TS 103 466 V1.1.1 (2016-10)7 audio bit stream:
38、 sequence of consecutive audio frames audio frame: frame of a duration of 24 ms (at 48 kHz sampling frequency) or of 48 ms (at 24 kHz sampling frequency) which contains a Layer II encoded audio signal ISO/IEC 11172-3 2, ISO/IEC 13818-3 4, corresponding to 1 152 consecutive audio samples NOTE: It is
39、the smallest part of the audio bit stream which is decodable on its own. audio mode: audio coding system provides single channel, dual channel, stereo and joint stereo audio modes NOTE: In each mode, the complete audio signal is encoded as one audio bit stream. bark: unit of the critical band NOTE:
40、The Bark scale is a non-linear mapping of the frequency scale over the entire audio frequency range. bit allocation: time-varying assignment of bits to samples in different sub-bands according to a psychoacoustic model bound: lowest sub-band in which Intensity stereo coding is used, in the case of j
41、oint stereo mode Common Interleaved Frame (CIF): serial digital output from the main service multiplexer which is contained in the Main Service Channel part of the transmission frame NOTE: It is common to all transmission modes and contains 55 296 bits (i.e. 864 CUs). convolutional coding: coding pr
42、ocedure which generates redundancy in the transmitted data stream in order to provide ruggedness against transmission distortions critical band: psychoacoustic measure in the frequency domain which corresponds to the frequency selectivity of the human ear DAB audio frame: Same as audio frame, but in
43、cludes all specific DAB audio-related information. dual channel mode: audio mode, in which two audio channels with independent programme contents (e.g. bilingual) are encoded within one audio bit stream NOTE: The coding process is the same as for the Stereo mode. Equal Error Protection (EEP): error
44、protection procedure which ensures a constant protection of the bit stream Extended Programme Associated Data (X-PAD): extended part of the PAD carried towards the end of the DAB audio frame, immediately before the Scale Factor Cyclic Redundancy Check (CRC) NOTE: Its length is variable. Fixed Progra
45、mme Associated Data (F-PAD): fixed part of the PAD contained in the last two bytes of the DAB audio frame intensity stereo coding: method of exploiting stereo irrelevance or redundancy in stereophonic audio programmes NOTE: It is based on retaining only the energy envelope of the right and left chan
46、nels at high frequencies. At low frequencies, the fine structure of the left and right channel of a stereophonic signal is retained. joint stereo mode: audio mode in which two channels forming a stereo pair (left and right) are encoded within one bit stream and for which stereophonic irrelevance or
47、redundancy is exploited for further bit reduction NOTE: The method used in the DAB system is Intensity stereo coding. logical frame: data burst, contributing to the contents of a sub-channel, during a time interval of 24 ms EXAMPLE: Data bursts at the output of an audio encoder, a Conditional Access
48、 scrambler and a convolutional encoder are referred to as logical frames. The number of bits contained in a specific logical frame depends on the stage in the encoding process and the bit rate associated with the sub-channel. Main Service Channel (MSC): channel which occupies the major part of the t
49、ransmission frame and which carries all the digital audio service components, together with possible supporting and additional data service components ETSI ETSI TS 103 466 V1.1.1 (2016-10)8 masking: property of the human auditory system by which an audio signal cannot be perceived in the presence of another audio signal masking threshold: function of frequency and time, specifying the sound pressure level below which an audio signal cannot be perceived by the human auditory system N: length of Fast Fourier Transform (FFT) polyphase filter bank: set of e
