1、 IEC 61937-3 Edition 3.0 2017-07 REDLINE VERSION Digital audio Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 Part 3: Non-linear PCM bitstreams according to the AC-3 and enhanced AC-3 formats IEC 61937-3:2017-07 RLV(en) colour inside THIS PUBLICATION IS COPYRIGHT PROTECTED
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11、ear PCM encoded audio bitstreams applying IEC 60958 Part 3: Non-linear PCM bitstreams according to the AC-3 and enhanced AC-3 formats INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 33.160.30 ISBN 978-2-8322-4677-1 Registered trademark of the International Electrotechnical Commission Warning! Make sur
12、e that you obtained this publication from an authorized distributor. colour inside 2 IEC 61937-3:2017 RLV IEC 2017 CONTENTS FOREWORD . 3 1 Scope 5 2 Normative references 5 3 Terms, definitions and abbreviated terms 5 3.7 Abbreviated terms . 6 4 Mapping of the audio bitstream on to IEC 61937-1 6 4.1
13、General . 6 4.2 AC-3 and enhanced AC-3 burst-info 6 5 Format of AC-3 and enhanced AC-3 data-bursts 7 5.1 General . 7 5.2 Pause data-burst 7 5.3 Audio data-bursts 8 5.3.1 AC-3 data 8 5.3.2 Latency of AC-3 decoding 9 5.3.3 Enhanced AC-3 data 10 5.3.4 Latency of the enhanced AC-3 decoder . 12 Bibliogra
14、phy 14 Figure 1 AC-3 data-burst, with reference point R 8 Figure 2 Latency of AC-3 decoding 9 Figure 3 Enhanced AC-3 data-burst . 11 Figure 4 Latency of enhanced AC-3 decoding 12 Table 1 Fields of burst-info 7 Table 2 Repetition period of the pause data-bursts 7 Table 3 Data-type-dependent informati
15、on when data-type bits 0-4= 1 . 8 Table 4 Data-type-dependent information when data-type bits 0-4 = 21 and data- type bits 5-6 = 0 11 Table 5 Frame repetition period and maximum data rate for enhanced AC-3 bitstreams . Table 5 Maximum enhanced AC-3 burst-payload size and bitstream data rate per samp
16、ling frequency and IEC 60958 frame rate 12 IEC 61937-3:2017 RLV IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ DIGITAL AUDIO INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO BITSTREAMS APPLYING IEC 60958 Part 3: Non-linear PCM bitstreams according to the AC-3 and enhanced AC-3 formats FOREWORD 1)
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28、 have been made to the previous version. Only the current version of the standard is to be considered the official document. This Redline version provides you with a quick and easy way to compare all the changes between this standard and its previous edition. A vertical bar appears in the margin whe
29、rever a change has been made. Additions are in green text, deletions are in strikethrough red text. 4 IEC 61937-3:2017 RLV IEC 2017 International Standard IEC 61937-3 has been prepared by subcommittee technical area 4: Digital system interfaces and protocols, of IEC technical committee 100: Audio, v
30、ideo and multimedia systems and equipment. This third edition of IEC 61937-3 cancels and replaces the second edition published in 2007. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) removal of
31、 support for enhanced AC-3 bitstreams with a sampling frequency of 32 kHz; b) updates to normative and informative references; c) clarification of pause data-burst usage for enhanced AC-3 bitstreams. The text of this International Standard is based on the following documents: CDV Report on voting 10
32、0/2720/CDV 100/2934/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 has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 61973 series, pub
33、lished 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 that the contents of this document will remain unchanged until the stability date indicated on the IEC website under “http
34、:/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 version of this publication may be issued at a later date. IMPORTANT The “colour inside” logo on the cover page of this p
35、ublication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this publication using a colour printer. IEC 61937-3:2017 RLV IEC 2017 5 DIGITAL AUDIO INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO BITSTREAMS APP
36、LYING IEC 60958 Part 3: Non-linear PCM bitstreams according to the AC-3 and enhanced AC-3 formats 1 Scope This part of IEC 61937 describes the method used to convey non-linear PCM bitstreams encoded according to the AC-3 and enhanced AC-3 formats. 2 Normative references The following documents are r
37、eferred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60958 (all parts), Dig
38、ital audio interface IEC 61937-1:2007, Digital audio interface for non-linear PCM encoded audio bit streams applying IEC 60958 Part 1: General IEC 61937-1:2007/AMD1:2011, Digital audio interface for non-linear PCM encoded audio bit streams applying IEC 60958 Part 1: General IEC 61937-2:2007, Digital
39、 audio interface for non-linear PCM encoded audio bit streams applying IEC 60958 Part 2: Burst-info ATSC Standard A/52B, Digital Audio Compression (AC-3, E-AC-3), Rev. B ETSI TS 102 366, Digital Audio Compression (AC-3, Enhanced AC-3) Standard 3 Terms, definitions and abbreviated terms For the purpo
40、ses of this document, the following terms and definitions and abbreviations 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.
41、org/obp 6 IEC 61937-3:2017 RLV IEC 2017 3.1 block identification flag if the stream type value of an enhanced AC-3 substream is two, indicating that the bitstream has been converted from an AC-3 bitstream, this bit is set to 1 to indicate that the first block in this enhanced AC-3 frame was the firs
42、t block in the original standard AC-3 frame flag used to indicate that the first audio block of an enhanced AC-3 syncframe with a stream type value of two formed the first audio block in the AC-3 syncframe from which it was converted 3.2 converter synchronization flag flag used for synchronization b
43、y a device that converts an enhanced AC-3 bitstream to a bitstream compliant with an AC-3 decoder and indicates that the first block in this enhanced AC-3 syncframe will form the first block of the AC-3 syncframe output by the conversion process 3.3 latency delay time of an external audio decoder to
44、 decode an AC-3 or enhanced AC-3 data burst, defined as the sum of two values: the receiving delay time and the decoding delay time 3.4 stream type parameter of an enhanced AC-3 syncframe identifying the type of substream of which the syncframe is a part Note 1 to entry: An enhanced AC-3 bitstream i
45、s constructed from one or more substreams, with each substream being constructed from a sequence of syncframes. 3.5 substream identification substream identification parameter of an enhanced AC-3 syncframe which, in conjunction with the stream type parameter, identifies the substream in the bitstrea
46、m of which the enhanced AC-3 syncframe is a part 3.6 syncframe minimum portion of the AC-3 or enhanced AC-3 audio serial bitstream capable of being fully decoded, also known as a synchronization frame 3.7 Abbreviated terms ATSC Advanced Television Standards Systems Committee ETSI European Telecommun
47、ications Standards Institute IEC International Electrotechnical Commission ISO/IEC MPEG Moving Pictures Expert Group, a joint committee of ISO and IEC 4 Mapping of the audio bitstream on to IEC 61937-1 4.1 General The coding of the bitstream and data-burst is in accordance with IEC 61937-1, IEC 6193
48、7-1:2007/AMD1:2011 and IEC 61937-2, including field names such as “Pc“, “Pa“ and “R“. 4.2 AC-3 and enhanced AC-3 burst-info The 16-bit burst-info contains information about the data that will be found in the data-burst (see Table 1). IEC 61937-3:2017 RLV IEC 2017 7 Table 1 Fields of burst-info Data-
49、 type Value of Pc bits 0-4 Sub- data- type Value of Pc bits 5-6 Contents Reference point R Repetition period of data-burst measured in IEC 60958 frames 1 0 AC-3 R-AC-3 1 536 21 0 Enhanced AC-3 Bit 0 of Pa 6 144 1-3 Reserved Reserved Reserved Bits of Pc Data-type bits 0-4 Data-type bits 5-6 Contents Reference point R Repetition period of data-burst measured in IEC 60958 frames 0 to 6 1 0 AC-3 R-AC-3 1 536 1 to 3 Reserved 2 to 20 According to IEC 61937 21 0 Enhanced AC-3 Bi
