1、 IEC 61937-10 Edition 2.0 2017-07 INTERNATIONAL STANDARD Digital audio interface for non-linear PCM encoded audio bitstreams applying IEC 60958 Part 10: Non-linear PCM bitstreams according to the MPEG-4 audio lossless coding (ALS) format IEC 61937-10:2017-07(en) THIS PUBLICATION IS COPYRIGHT PROTECT
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11、for non-linear PCM encoded audio bitstreams applying IEC 60958 Part 10: Non-linear PCM bitstreams according to the MPEG-4 audio lossless coding (ALS) format INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 33.160.30; 35.240.99 ISBN 978-2-8322-4560-6 Registered trademark of the International Electrotech
12、nical Commission Warning! Make sure that you obtained this publication from an authorized distributor. 2 IEC 61937-10:2017 IEC 2017 CONTENTS FOREWORD . 3 1 Scope 5 2 Normative references 5 3 Terms, definitions, abbreviated terms and conventions 5 3.1 Terms and definitions 5 3.2 Abbreviated terms . 7
13、 3.3 Presentation convention 7 4 Mapping of the audio bitstream onto IEC 61937 . 7 4.1 General . 7 4.2 MPEG-4 ALS burst-info . 7 5 Format of MPEG-4 ALS data-bursts . 8 5.1 General . 8 5.2 Audio data-bursts 9 5.2.1 Data-burst for MPEG-4 ALS . 9 5.2.2 Latency of MPEG-4 ALS decoding . 10 5.2.3 Data-bur
14、st for MPEG-4 ALS in LATM/LOAS . 12 Annex A (informative) Effect of repetition period of data-burst and IEC 60958 frame rate on frame period for the MPEG-4 ALS bitstreams 13 Annex B (normative) Burst payload format for MPEG-4 ALS 14 Annex C (normative) Values for ALSSpecificConfig in the MPEG-4 ALS
15、burst payload format 15 Annex D (informative) Example use case of the ALS simple profile in LATM/LOAS 17 Figure 1 MPEG-4 ALS data-burst . 9 Figure 2 Latency of MPEG-4 ALS decoding . 11 Figure 3 The MPEG-4 ALS burst-payload . 11 Figure 4 MPEG-4 ALS burst-payload with LATM/LOAS header 12 Figure B.1 MP
16、EG-4 ALS burst-payload 14 Table 1 Fields of burst-info (data-type bits 0-4=23, data-type bits 5-6=0/ data-type bits 0-4=25, data-type bits 5-6=2) . 8 Table 2 Sampling frequency, multiplier, and IEC 60958 frame rate . 10 Table A.1 MPEG-4 ALS payload and frame repetition: some examples 13 Table C.1 Re
17、commended values for the ALSSpecificConfig in the MPEG-4 ALS burst-payload 15 Table D.1 MPEG-4 ALS simple profile, maximum payload size and frame repetition: some examples . 17 IEC 61937-10:2017 IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ DIGITAL AUDIO INTERFACE FOR NON-LINEAR PCM ENCODED
18、 AUDIO BITSTREAMS APPLYING IEC 60958 Part 10: Non-linear PCM bitstreams according to the MPEG-4 audio lossless coding (ALS) format FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC
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29、ts. International Standard IEC 61937-10 has been prepared by technical area 4: Digital system interfaces and protocols, of IEC technical committee 100: Audio, video and multimedia systems and equipment. This second edition cancels and replaces the first edition published in 2011. This edition consti
30、tutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) Addition of Levels 2, 3, 4 of MPEG-4 ALS Simple Profile; b) Addition of data-type bits 0-4 and data-type bits 5-6 for MPEG-4 ALS with LATM/LOAS header. 4 IEC 61937-1
31、0:2017 IEC 2017 The text of this International Standard is based on the following documents: CDV Report on voting 100/2630/CDV 100/2930/RVC Full information on the voting for the approval of this International Standard can be found in the report on voting indicated in the above table. This document
32、has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all the parts in the IEC 61937 series, published under the general title Digital audio Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 can be found on the IEC website. The committee has decided tha
33、t the contents of this document will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific document. At this date, the document will be reconfirmed, withdrawn, replaced by a revised edition, or amended. A bilingual ve
34、rsion of this publication may be issued at a later date. IEC 61937-10:2017 IEC 2017 5 DIGITAL AUDIO INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO BITSTREAMS APPLYING IEC 60958 Part 10: Non-linear PCM bitstreams according to the MPEG-4 audio lossless coding (ALS) format 1 Scope This part of IEC 61937 sp
35、ecifies the method for IEC 60958 to convey non-linear PCM bitstreams encoded in accordance with the MPEG-4 audio lossless coding (ALS) format. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this d
36、ocument. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60958-1, Digital audio interface Part 1: General IEC 60958-3, Digital audio interface Part 3: Consumer applications IEC 61937-1
37、, Digital audio 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 14496-3:2009, Information technology Coding of audio-visual objects
38、Part 3: Audio ISO/IEC 14496-3:2009/AMD2:2010, ALS simple profile and transport of SAOC ISO/IEC 14496-3:2009/AMD5:2015, Support for Dynamic Range Control, New Levels for ALS Simple Profile, and Audio Synchronization 3 Terms, definitions, abbreviated terms and conventions 3.1 Terms and definitions For
39、 the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp
40、3.1.1 als_id ALS identifier in ALSSpecificConfig 6 IEC 61937-10:2017 IEC 2017 3.1.2 ALS Simple Profile MPEG-4 ALS Simple Profile defined by ISO/IEC 14496-3:2009/AMD2:2010 and ISO/IEC 14496-3:2009/AMD5:2015 3.1.3 aux_data auxiliary data contained in the MPEG-4 ALS burst payload Note 1 to entry: Not r
41、equired for decoding audio samples. 3.1.4 aux_size size of the auxiliary data field in bytes for MPEG-4 ALS 3.1.5 channels number of channels-1, channels, contained in the MPEG-4 ALS burst payload 3.1.6 latency delay time of an external audio decoder to decode a MPEG-4 ALS data-burst, defined as the
42、 sum of the receiving delay time and the decoding delay time 3.1.7 length code code indicating the length of the data-burst-payload in 8-byte units according to this standard 3.1.8 low overhead audio stream LOAS synchronisation layer defined by ISO/IEC 14496-3 Note 1 to entry: Three different format
43、s of LOAS are defined, each of which is designed to address the specific characteristics of the underlying transmission layer. AudioSyncStream shall be used. 3.1.9 low-overhead MPEG-4 audio transport multiplex LATM multiplexing layer defined by ISO/IEC 14496-3 Note 1 to entry: LATM is used for multi
44、plexing of audio elementary streams. AudioMuxElement shall be used. 3.1.10 resolution bit depth of the audio samples contained in the MPEG-4 ALS burst payload 3.1.11 samples number of audio samples per channel contained in the MPEG-4 ALS burst payload Note 1 to entry: In contrast to the ALS specific
45、ation, each data-burst provides its own ALSSpecificConfig. Thus the samples value refers to the total number of samples (per channel) of that data-burst. 3.1.12 samp_freq sampling frequency of the audio samples contained in the MPEG-4 ALS burst payload IEC 61937-10:2017 IEC 2017 7 3.2 Abbreviated te
46、rms ALS audio lossless coding PCM pulse-code modulation 3.3 Presentation convention 01 2Value “01“ in binary format 4 Mapping of the audio bitstream onto IEC 61937 4.1 General The coding of the bitstream and data-burst is in accordance with the IEC 61937 series of standards. 4.2 MPEG-4 ALS burst-inf
47、o The 16-bit burst-info contains information about the data that will be found in the data-burst in accordance with Table 1. 8 IEC 61937-10:2017 IEC 2017 Table 1 Fields of burst-info (data-type bits 0-4=23, data-type bits 5-6=0/ data-type bits 0-4=25, data-type bits 5-6=2) Bits of Pc Value Contents
48、Reference point R Repetition period of data-burst in IEC 60958 frames 0 to 4 data-type bits 0-4 0-22 In accordance with IEC 61937-2 23 MPEG-4 ALS or other applications according to IEC 61937-2, depending on data-type bits 5-6 Bit 0 of Pa See 5.2.1 24-24 In accordance with IEC 61937-2 25 MPEG-4 ALS o
49、r other applications according to IEC 61937-2, depending on data-type bits 5-6 Bit 0 of Pa See 5.2.1 26-31 In accordance with IEC 61937-2 5, 6 data-type bits 5-6 for data-type bits 0-4 23 0 MPEG-4 ALS See 5.2.1 1-3 In accordance with IEC 61937-2 data-type bits 5-6 for data-type bits 0-4 25 0-1 In accordance with IEC 61937-2 See 5.2.1 2 MPEG-4 ALS in LATM/LOAS 3 In accordance with IEC 61937-2 7 0 Error-flag indicating a valid burst-payload 1 Burst may con
