ISO/IEC 13818-7:2003
(Main)Information technology — Generic coding of moving pictures and associated audio information — Part 7: Advanced Audio Coding (AAC)
Information technology — Generic coding of moving pictures and associated audio information — Part 7: Advanced Audio Coding (AAC)
Technologies de l'information — Codage générique des images animées et du son associé — Partie 7: Codage du son avancé (AAC)
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Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 13818-7
Second edition
2003-08-01
Information technology — Generic
coding of moving pictures and
associated audio information —
Part 7:
Advanced Audio Coding (AAC)
Technologies de l'information — Codage générique des images
animées et du son associé —
Partie 7: Codage du son avancé (AAC)
Reference number
ISO/IEC 13818-7:2003(E)
©
ISO/IEC 2003
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ISO/IEC 13818-7:2003(E)
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ii © ISO/IEC 2003 – All rights reserved
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ISO/IEC 13818-7:2003(E)
Contents 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
4.4 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 Detection. 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 Profile 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 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 Definitions. 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
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ISO/IEC 13818-7:2003(E)
8.4 Low 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 Range 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 Definitions.70
9.2.1 Data elements.70
9.2.2 Help elements.71
9.3 Decoding process.72
9.4 Tables.75
10 Quantization.75
10.1 Tool description.75
10.2 Definitions.75
10.2.1 Help elements.75
10.3 Decoding process.76
11 Scalefactors.76
11.1 Tool description.76
11.2 Definitions.76
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.77
11.3.2 Decoding of scalefactors.77
11.3.3 Applying scalefactors.77
12 Joint coding.78
12.1 M/S stereo.78
12.1.1 Tool description.78
12.1.2 Definitions.78
12.1.3 Decoding process.79
12.2 Intensity stereo.79
12.2.1 Tool description.79
12.2.2 Definitions.80
12.2.3 Decoding process.80
12.2.4 Integration with intra channel prediction tool.81
12.3 Coupling channel.81
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 Definitions.86
13.2.1 Data elements.86
13.3 Decoding process.86
13.3.1 Predictor side information.87
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ISO/IEC 13818-7:2003(E)
13.3.2 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 switching. 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. 101
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) Huffman 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 Quantization. 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 information 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
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ISO/IEC 13818-7:2003(E)
Foreword
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 International 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 liaison 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 technical 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 13818-7 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 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 Audio 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
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ISO/IEC 13818-7:2003(E)
Introduction
The standardization body ISO/IEC 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 development, 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.
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INTERNATIONAL STANDARD ISO/IEC 13818-7:2003(E)
Information 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 higher 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 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 Formatter Required
Noiseless Decoding Required
Inverse quantization Required
Rescaling Required
M/S Optional
Prediction Optional
Intensity Optional
Dependently switched coupling Optional
TNS Optional
Filterbank / block switching Required
Gain control Optional
Independently switched coupling Optional
1.1 MPEG-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 description 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 spectr
...
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