ANSI INCITS ISO IEC 13818-7-2003 Information technology Generic coding of moving pictures and associated audio information Part 7 Advanced Audio Coding (AAC) (Adopted by INCITS).pdf

1、Adopted by INCITS (InterNational Committee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 12/24/2003Published by American National Standards Institute,25 West 43rd Street, New York, New York 10036Copyright 2003 by Information Technology Industry Council

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3、his publication may be reproduced in any form, including an electronic retrieval system, withoutthe prior written permission of ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaReference numberISO

4、/IEC 13818-7:2003(E)ISO/IEC 2003INTERNATIONAL STANDARD ISO/IEC13818-7Second edition2003-08-01Information technology Generic coding of moving pictures and associated audio information Part 7: Advanced Audio Coding (AAC) Technologies de linformation Codage gnrique des images animes et du son associ Pa

5、rtie 7: Codage du son avanc (AAC) ISO/IEC 13818-7:2003(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the c

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9、either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2003 All rights reservedISO/IEC 13818-7

10、:2003(E) ISO/IEC 2003 All rights reserved iiiContents Page Foreword vi Introduction vii 1 Scope 1 1.1 MPEG-2 AAC Tools Overview . 1 2 Normative references 8 3 Terms and definitions . 8 4 Symbols and abbreviations 15 4.1 Arithmetic operators 15 4.2 Logical operators 16 4.3 Relational operators . 16 4

11、.4 Bitwise operators 16 4.5 Assignment . 16 4.6 Mnemonics 16 4.7 Constants 17 5 Method of describing bitstream syntax 17 6 Syntax. 19 6.1 Audio Data Interchange Format, ADIF 19 6.2 Audio Data Transport Stream, ADTS 19 6.2.1 Fixed Header of ADTS 21 6.2.2 Variable Header of ADTS . 21 6.2.3 Error Detec

12、tion . 21 6.3 Raw Data 21 7 Profiles . 33 7.1 Profiles. 33 7.1.1 Main . 33 7.1.2 Low complexity. 33 7.1.3 Scalable sampling rate 33 7.1.4 Naming convention for MPEG-2 AAC decoders and bitstreams. 33 7.1.5 Minimum decoder capability for specified number of main audio channels and profile . 34 7.1.6 P

13、rofile dependent tool parameters. 34 7.2 Profile interoperability 34 7.2.1 Interoperability of bitstreams and decoders . 34 8 General information 35 8.1 Audio Data Interchange Format (ADIF) and Audio Data Transport Stream (ADTS) 35 8.1.1 Definitions. 35 8.1.2 Overview 39 8.1.3 Audio Data Interchange

14、 Format ADIF 40 8.1.4 Audio Data Transport Stream ADTS 40 8.2 Decoding of raw data . 40 8.2.1 Definitions. 40 8.2.2 Buffer requirements . 42 8.2.3 Decoding process 43 8.3 Decoding of a single_channel_element() (SCE), a channel_pair_element() (CPE) or an individual_channel_stream() (ICS). 44 8.3.1 De

15、finitions. 44 8.3.2 Decoding process 46 8.3.3 Windows and window sequences 48 8.3.4 Scalefactor bands and grouping 48 8.3.5 Order of spectral coefficients in spectral_data() 50 8.3.6 Output word length 50 8.3.7 Matrix-mixdown method 51 ISO/IEC 13818-7:2003(E) iv ISO/IEC 2003 All rights reserved8.4 L

16、ow Frequency Enhancement Channel (LFE) .52 8.4.1 General 52 8.5 Program Config Element (PCE).52 8.5.1 Implicit and defined channel configurations .54 8.6 Data Stream Element (DSE) .55 8.6.1 Data elements .55 8.6.2 Decoding process.55 8.7 Fill element (FIL)55 8.7.1 Fill element including Dynamic Rang

17、e Control (DRC)55 8.7.2 Decoding process.57 8.7.3 DRC decoding process 57 8.7.4 Persistence of DRC information .60 8.8 Tables.61 8.9 Figures .69 9 Noiseless coding .69 9.1 Tool description 69 9.2 Definitions70 9.2.1 Data elements .70 9.2.2 Help elements .71 9.3 Decoding process.72 9.4 Tables.75 10 Q

18、uantization .75 10.1 Tool description 75 10.2 Definitions75 10.2.1 Help elements .75 10.3 Decoding process.76 11 Scalefactors .76 11.1 Tool description 76 11.2 Definitions76 11.2.1 Data functions 76 11.2.2 Data elements .76 11.2.3 Help elements .76 11.3 Decoding process.77 11.3.1 Scalefactor bands 7

19、7 11.3.2 Decoding of scalefactors.77 11.3.3 Applying scalefactors77 12 Joint coding .78 12.1 M/S stereo78 12.1.1 Tool description .78 12.1.2 Definitions.78 12.1.3 Decoding process 79 12.2 Intensity stereo79 12.2.1 Tool description .79 12.2.2 Definitions.80 12.2.3 Decoding process 80 12.2.4 Integrati

20、on with intra channel prediction tool.81 12.3 Coupling channel81 12.3.1 Tool description .81 12.3.2 Definitions.81 12.3.3 Decoding process 82 12.3.4 Tables 85 13 Prediction .85 13.1 Tool description 85 13.2 Definitions86 13.2.1 Data elements .86 13.3 Decoding process.86 13.3.1 Predictor side informa

21、tion.87 ISO/IEC 13818-7:2003(E) ISO/IEC 2003 All rights reserved v13.3.2 Predictor processing . 87 13.3.3 Predictor reset 91 13.4 Diagrams 92 14 Temporal Noise Shaping (TNS) 93 14.1 Tool description 93 14.2 Definitions . 93 14.2.1 Data elements. 93 14.3 Decoding process. 94 15 Filterbank and block s

22、witching 96 15.1 Tool description 96 15.2 Definitions . 96 15.2.1 Data elements. 96 15.3 Decoding process. 96 15.3.1 IMDCT 96 15.3.2 Windowing and block switching 97 15.3.3 Overlapping and adding with previous window sequence . 100 16 Gain control . 100 16.1 Tool description 100 16.2 Definitions . 1

23、01 16.2.1 Data elements. 101 16.2.2 Help elements. 101 16.3 Decoding process. 102 16.3.1 Gain control data decoding 102 16.3.2 Gain control function setting 103 16.3.3 Gain control windowing and overlapping . 105 16.3.4 Synthesis filter . 106 16.4 Diagrams 107 16.5 Tables. 107 Annex A (normative) Hu

24、ffman Codebook Tables . 109 Annex B (informative) Information on unused codebooks 129 Annex C (informative) Encoder. 130 C.1 Psychoacoustic model. 130 C.2 Gain control. 165 C.3 Filterbank and block switching . 166 C.4 Prediction 168 C.5 Temporal Noise Shaping (TNS). 171 C.6 Joint coding. 173 C.7 Qua

25、ntization 175 C.8 Noiseless coding 181 Annex D (informative) Patent holders 184 D.1 List of patent holders . 184 Annex E (informative) Registration procedure . 185 E.1 Procedure for the request of a Registered Identifier (RID). 185 E.2 Responsibilities of the Registration Authority 185 E.3 Contact i

26、nformation of the Registration Authority 185 E.4 Responsibilities of parties requesting an RID. 185 E.5 Appeal procedure for denied applications. 186 Annex F (informative) Registration application form. 187 Annex G (informative) Registration Authority. 188 Bibliography . 189 ISO/IEC 13818-7:2003(E)

27、vi ISO/IEC 2003 All rights reservedForeword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of Int

28、ernational Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liais

29、on with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint techn

30、ical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. ISO/IEC 13818-

31、7 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information. This second edition cancels and replaces the first edition (ISO/IEC 13818-7:1997), which has been technically revised. ISO/IEC 13818

32、 consists of the following parts, under the general title Information technology Generic coding of moving pictures and associated audio information: Part 1: Systems Part 2: Video Part 3: Audio Part 4: Conformance testing Part 5: Software simulation Part 6: Extensions for DSM-CC Part 7: Advanced Audi

33、o Coding (AAC) Part 9: Extension for real time interface for systems decoders Part 10: Conformance extensions for Digital Storage Media Command and Control (DSM-CC) Part 11: IPMP on MPEG-2 systems ISO/IEC 13818-7:2003(E) ISO/IEC 2003 All rights reserved viiIntroduction The standardization body ISO/I

34、EC JTC 1/SC 29/WG 11, also known as the Moving Pictures Experts Group (MPEG), was established in 1988 to specify digital video and audio coding schemes at low data rates. MPEG completed its first phase of audio specifications (MPEG-1) in November 1992, ISO/IEC 11172-3. In its second phase of develop

35、ment, the MPEG Audio subgroup defined a multichannel extension to MPEG-1 audio that is backwards compatible with existing MPEG-1 systems (MPEG-2 BC) and defined an audio coding standard at lower sampling frequencies than MPEG-1, ISO/IEC 13818-3. INTERNATIONAL STANDARD ISO/IEC 13818-7:2003(E) ISO/IEC

36、 2003 All rights reserved 1Information technology Generic coding of moving pictures and associated audio information Part 7: Advanced Audio Coding (AAC) 1 Scope This International Standard describes the MPEG-2 audio non-backwards compatible standard called MPEG-2 Advanced Audio Coding, AAC 1, a high

37、er quality multichannel standard than achievable while requiring MPEG-1 backwards compatibility. This MPEG-2 AAC audio standard allows for ITU-R indistinguishable quality according to 2 at data rates of 320 kbit/s for five full-bandwidth channel audio signals. The AAC decoding process makes use of a

38、 number of required tools and a number of optional tools. Table 1 lists the tools and their status as required or optional. Required tools are mandatory in any possible profile. Optional tools may not be required in some profiles. Table 1 AAC decoder tools Tool Name Required / Optional Bitstream For

39、matter Required Noiseless Decoding Required Inverse quantization Required Rescaling RequireM/S Optional Prediction OptionaIntensity Optional Dependently switched coupling Optional TNS OptionaFilterbank / block switching Required Gain control Optional Independently switched coupling Optional 1.1 MPEG

40、-2 AAC Tools Overview The basic structure of the MPEG-2 AAC system is shown in Figure 1 and Figure 2. As is shown in Table 1, there are both required and optional tools in the decoder. The data flow in this diagram is from left to right, top to bottom. The functions of the decoder are to find the de

41、scription of the quantized audio spectra in the bitstream, decode the quantized values and other reconstruction information, reconstruct the quantized spectra, process the reconstructed spectra through whatever tools are active in the bitstream in order to arrive at the actual signal spectra as desc

42、ribed by the input bitstream, and finally convert the frequency domain spectra to the time domain, with or without an optional gain control tool. Following the initial reconstruction and scaling of the spectrum reconstruction, there are many optional tools that modify one or more of the spectra in o

43、rder to provide more efficient coding. For each of the optional tools that operate in the spectral domain, the option to “pass through” is retained, and in all cases where a spectral operation is omitted, the spectra at its input are passed directly through the tool without modification. The input t

44、o the bitstream demultiplexer tool is the MPEG-2 AAC bitstream. The demultiplexer separates the parts of the MPEG-AAC data stream into the parts for each tool, and provides each of the tools with the bitstream information related to that tool. ISO/IEC 13818-7:2003(E) 2 ISO/IEC 2003 All rights reserv

45、edThe outputs from the bitstream demultiplexer tool are: The sectioning information for the noiselessly coded spectra The noiselessly coded spectra The M/S decision information (optional) The predictor state information (optional) The intensity stereo control information and coupling channel control

46、 information (both optional) The temporal noise shaping (TNS) information (optional) The filterbank control information The gain control information (optional) The noiseless decoding tool takes information from the bitstream demultiplexer, parses that information, decodes the Huffman coded data, and

47、 reconstructs the quantized spectra and the Huffman and DPCM coded scalefactors. The inputs to the noiseless decoding tool are: The sectioning information for the noiselessly coded spectra The noiselessly coded spectra The outputs of the Noiseless Decoding tool are: The decoded integer representatio

48、n of the scalefactors: The quantized values for the spectra The inverse quantizer tool takes the quantized values for the spectra, and converts the integer values to the non-scaled, reconstructed spectra. This quantizer is a non-uniform quantizer. The input to the Inverse Quantizer tool is: The quan

49、tized values for the spectra The output of the inverse quantizer tool is: The un-scaled, inversely quantized spectra The rescaling tool converts the integer representation of the scalefactors to the actual values, and multiplies the un-scaled inversely quantized spectra by the relevant scalefactors. The inputs to the rescaling tool are: The decoded integer representation of the scalefactors The un-scaled, inversely quantized spectra The output from the scalefactors tool is: