1、 INTERNATIONAL STANDARD IEC61937-6Second edition2006-01Digital audio Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4 AAC audio formats Reference number IEC 61937-6:2006(E) Publication numbering As from
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8、 +41 22 919 03 00 INTERNATIONAL STANDARD IEC61937-6Second edition2006-01Digital audio Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4 AAC audio formats IEC 2006 Copyright - all rights reserved No part o
9、f this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission, 3, rue de Varemb, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelep
10、hone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmailiec.ch Web: www.iec.ch S For price, see current cataloguePRICE CODE Commission Electrotechnique InternationaleInternational Electrotechnical Commission 2 61937-6 IEC:2006(E) CONTENTS FOREWORD.4 1 Scope.6 2 Normative references .6 3 Terms
11、, definitions, abbreviations and presentation convention 6 3.1 Terms and definitions .6 3.2 Abbreviations 7 3.3 Presentation convention 7 4 Mapping of the audio bitstream on to IEC 61937 7 4.1 MPEG-2 AAC burst-info.7 4.2 MPEG-4 AAC burst-info.8 5 Format of MPEG-2 AAC and MPEG-4 AAC data-bursts 8 5.1
12、 Pause data-burst.9 5.2 Audio data-bursts 9 Figure 1 MPEG-2 AAC data-burst 9 Figure 2 Latency of MPEG-2 AAC decoding.10 Figure 3 MPEG-2 AAC half-rate low sampling frequency data-burst .11 Figure 4 Latency of MPEG-2 AAC half-rate low sampling frequency decoding12 Figure 5 MPEG-2 AAC quarter-rate low
13、sampling frequency data-burst13 Figure 6 Latency of MPEG-2 AAC quarter-rate low sampling frequency decoding 14 Figure 7 MPEG-4 AAC data-burst 15 Figure 7 Latency of MPEG-4 AAC decoding.16 Figure 8 MPEG-4 AAC half-rate low sampling frequency data-burst .16 Figure 9 Latency of MPEG-4 AAC half-rate low
14、 sampling frequency decoding17 Figure 10 MPEG-4 AAC quarter-rate low sampling frequency data-burst18 Figure 11 Latency of MPEG-4 AAC quarter-rate low sampling frequency decoding 19 Figure 12 MPEG-4 AAC double-rate high sampling frequency data-burst .20 Figure 13 Latency of MPEG-4 AAC double-rate hig
15、h sampling frequency decoding21 Table 1 Fields of burst-info (data-type=7) 7 Table 2 Fields of burst-info (data-type=19).8 Table 3 Fields of burst-info (data-type=20).8 Table 4 Repetition period of pause data-bursts 9 Table 5 Repetition period of pause data-bursts 9 Table 6 Data-type-dependent infor
16、mation for data-type MPEG-2 AAC10 Table 7 Data-type-dependent information for data-type MPEG-2 AAC half-rate low sampling frequency.11 Table 8 Data-type-dependent information for data-type MPEG-2 AAC quarter-rate low sampling frequency .13 61937-6 IEC:2006(E) 3 Table 9 Data-type-dependent informatio
17、n for data-type MPEG-4 AAC15 Table 10 Data-type-dependent information for data-type MPEG-4 AAC half-rate low sampling frequency.17 Table 11 Data-type-dependent information for data-type MPEG-4 AAC quarter-rate low sampling frequency .18 Table 12 Data-type-dependent information for data-type MPEG-4 A
18、AC double-rate high sampling frequency 20 4 61937-6 IEC:2006(E) INTERNATIONAL ELECTROTECHNICAL COMMISSION _ DIGITAL AUDIO INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO BITSTREAMS APPLYING IEC 60958 Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4 AAC formats FOREWORD 1) The Inte
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29、identifying any or all such patent rights. International Standard IEC 61937-6 has been prepared by technical area 4: Digital systems interfaces, of IEC technical committee 100: Audio, video and multimedia systems and equipment. This second edition of IEC 61937-6 cancels and replaces the first editio
30、n published in 2002. This edition contains the following significant technical changes with respect to the previous edition: a) addition of data-type for MPEG2 AAC low sampling frequency; b) addition of data-type for MPEG-4 AAC. 61937-6 IEC:2006(E) 5 The text of this standard is based on the followi
31、ng documents: CDV Report on voting 100/942/CDV 100/1043A/RVCFull information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. IEC 61937 consists of t
32、he following parts under the general title Digital audio Interface for non-linear PCM encoded audio bitstreams applying IEC 60958: Part 1: General Part 2: Burst-info Part 3: Non-linear bitstreams according to the AC-3 format Part 4: Non-linear PCM bitstreams according to the MPEG audio formats Part
33、5: Non-linear PCM bitstreams according to the DTS (Digital Theater Systems) format(s) Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4 AAC formats Part 7: Non-linear PCM bitstreams according to the ATRAC, ATRAC2/3 and ATRAC-X formats The committee has decided that the content
34、s of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended. A biling
35、ual version of this document may be issued at a later date. 6 61937-6 IEC:2006(E) DIGITAL AUDIO INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO BITSTREAMS APPLYING IEC 60958 Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4 AAC formats 1 Scope This part of IEC 61937 specifies the m
36、ethod for IEC 60958 to convey non-linear PCM bitstreams encoded in accordance with the MPEG-2 AAC (Advanced Audio Coding) and MPEG-4 AAC formats. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition c
37、ited applies. For undated references, 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, Digital au
38、dio Interface for non-linear 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 ISO/IEC 13818-7:2004, Information technology Generic coding of moving pictures and assoc
39、iated audio information Part 7: Advanced Audio Coding (AAC) ISO/IEC 14496-3:2001, Information technology Coding of audio-visual objects Part 3: Audio Amendment 1 (2003) 3 Terms, definitions, abbreviations and presentation convention For the purposes of this document, the following terms, definitions
40、, abbreviations and presentation convention apply. 3.1 Terms and definitions 3.1.1 subdata-type reference to the type of payload of the data-burst defined for use with the specified data-type 3.1.2 LC profile low complexity profile identified in ISO/IEC 13818-7 61937-6 IEC:2006(E) 7 3.1.3 LC profile
41、 with SBR low complexity profile with spectral band replication identified in ISO/IEC 13818-7 3.1.4 latency delay time of an external audio decoder to decode a MPEG-2 AAC or MPEG-4 AAC data-burst defined as the sum of two values of the receiving delay time and the decoding delay time 3.1.5 AAC profi
42、le AAC profile identified in ISO/IEC 14496-3 3.1.6 HE-AAC profile HE-AAC profile identified in ISO/IEC 14496-3 3.2 Abbreviations AAC Advanced Audio Coding ADTS Audio Data Transport Stream SBR Spectral Band Replication HE-AAC High Efficiency AAC 3.3 Presentation convention 012Value “01” in binary for
43、mat 4 Mapping of the audio bitstream on to IEC 61937 The coding of the bitstream and data-burst is in accordance with IEC 61937. 4.1 MPEG-2 AAC burst-info MPEG-2 AAC burst-info (data-type=7) is given in Table 1. Table 1 Fields of burst-info (data-type=7) Bits of Pc Value Contents Reference point R R
44、epetition period of data-burst in IEC 60958 frames 0-4 Data-type 7 MPEG-2 AAC ADTS Bit 0 of Pa 1 024 5,6 002Reserved 7-15 In accordance with IEC 61937-1 and IEC 61937-2 MPEG-2 AAC burst-info (data-type=19) is given in Table 2. 8 61937-6 IEC:2006(E) Table 2 Fields of burst-info (data-type=19) Bits of
45、 Pc Value Contents Reference point R Repetition period of data-burst in IEC 60958 frames 0-4 Data-type 19 MPEG-2 AAC ADTS low sampling frequency Depends on subdata-type 5,6 Subdata-type 002Subdata-type for MPEG-2 AAC ADTS half- rate low sampling frequency Bit 0 of Pa 2 048 012Subdata-type for MPEG-2
46、 AAC ADTS quarter-rate low sampling frequency Bit 0 of Pa 4 096 102,112Reserved 7-15 In accordance with IEC 61937-1 and IEC 61937-2 4.2 MPEG-4 AAC burst-info MPEG-4 AAC burst-info (data-type=20) is given in Table 3. Table 3 Fields of burst-info (data-type=20) Bits of Pc Value Contents Reference poin
47、t R Repetition period of data-burst in IEC 60958 frames 0-4 Data-type 20 MPEG-4 AAC Depends on subdata-type 5,6 Subdata-type002Subdata-type for MPEG4 AAC Bit 0 of Pa 1024 012Subdata-type for MPEG4 AAC half-rate low sampling frequency Bit 0 of Pa 2 048 102Subdata-type for MPEG4 AAC quarter-rate low s
48、ampling frequency Bit 0 of Pa 4 096 112Subdata-type for MPEG4 AAC double-rate high sampling frequency Bit 0 of Pa 512 7-15 In accordance with IEC 61937-1 and IEC 61937-2 5 Format of MPEG-2 AAC and MPEG-4 AAC data-bursts This clause specifies the audio data-bursts MPEG-2 AAC and MPEG-4 AAC. Specific
49、properties such as reference points, repetition period, the method of filling stream gaps, and decoding latency are specified for each data-type. The decoding latency (or delay), indicated for the data-types, should be used by the transmitter to schedule data-bursts as necessary to establish synchronization between the picture and the decoded audio. 61937-6 IEC:2006(E) 9
