IEC_61937-14-2017.pdf

IEC 61937-14 Edition 1.0 2017-08 INTERNATIONAL STANDARD Digital audio Interface for non-linear pcm encoded audio bitstreams applying IEC 60958 Part 14:Non-linear PCM bit streams according to the AC-4 format IEC 61937-14:2017-08(en)THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2017 IEC,Geneva,Switzerland All rights reserved.Unless otherwise specified,no part of 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 either IEC or IECs member National Committee in the country of the requester.If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,please contact the address below or your local IEC member National Committee for further information.IEC Central Office Tel.:+41 22 919 02 11 3,rue de Varemb Fax:+41 22 919 03 00 CH-1211 Geneva 20 infoiec.ch Switzerland www.iec.ch About the IEC The International Electrotechnical Commission(IEC)is the leading global organization that prepares and publishes International Standards for all electrical,electronic and related technologies.About IEC publications The technical content of IEC publications is kept under constant review by the IEC.Please make sure that you have the latest edition,a corrigenda or an amendment might have been published.IEC Catalogue-webstore.iec.ch/catalogue The stand-alone application for consulting the entire bibliographical information on IEC International Standards,Technical Specifications,Technical Reports and other documents.Available for PC,Mac OS,Android Tablets and iPad.IEC publications search-www.iec.ch/searchpub The advanced search enables to find IEC publications by a variety of criteria(reference number,text,technical committee,).It also gives information on projects,replaced and withdrawn publications.IEC Just Published-webstore.iec.ch/justpublished Stay up to date on all new IEC publications.Just Published details all new publications released.Available online and also once a month by email.Electropedia-www.electropedia.org The worlds leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and French,with equivalent terms in 16 additional languages.Also known as the International Electrotechnical Vocabulary(IEV)online.IEC Glossary-std.iec.ch/glossary 65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002.Some entries have been collected from earlier publications of IEC TC 37,77,86 and CISPR.IEC Customer Service Centre-webstore.iec.ch/csc If you wish to give us your feedback on this publication or need further assistance,please contact the Customer Service Centre:csciec.ch.IEC 61937-14 Edition 1.0 2017-08 INTERNATIONAL STANDARD Digital audio Interface for non-linear pcm encoded audio bitstreams applying IEC 60958 Part 14:Non-linear PCM bit streams according to the AC-4 format INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 33.160.30;33.170 ISBN 978-2-8322-4705-1 Registered trademark of the International Electrotechnical Commission Warning!Make sure that you obtained this publication from an authorized distributor.2 IEC 61937-14:2017 IEC 2017 CONTENTS FOREWORD.4 1 Scope.6 2 Normative references.6 3 Terms,definitions and abbreviated terms.6 3.6 Abbreviated terms.7 4 Mapping of the audio bit stream on to IEC 61937-1.7 4.1 General.7 4.2 AC-4 burst-info.7 5 Format of AC-4 data-bursts.8 5.1 General.8 5.2 Pause data-burst.8 5.3 Audio data-burst.8 5.3.1 The AC-4 data.8 5.3.2 Latency of the AC-4 decoder.12 5.3.3 The AC-4 HBR4 data.13 5.3.4 Latency of the AC-4 HBR4 decoder.16 5.3.5 The AC-4 HBR16 data.17 5.3.6 Latency of the AC-4 HBR16 decoder.20 5.3.7 The AC-4 LD data.21 5.3.8 Latency of the AC-4 LD decoder.23 Annex A(normative)AC-4 sync frame.25 Figure 1 AC-4 data-burst.9 Figure 2 Latency of AC-4 decoding.12 Figure 3 AC-4 HBR4 data-burst.13 Figure 4 Latency of AC-4 HBR4 decoding.16 Figure 5 AC-4 HBR16 data-burst.17 Figure 6 Latency of AC-4 HBR16 decoding.21 Figure 7 AC-4 LD data-burst.22 Figure 8 Latency of AC-4 LD decoding.24 Figure A.1 An AC-4 sync frame.25 Table 1 Shorthand notation for fractional frame rates.7 Table 2 Fields of burst-info.8 Table 3 Repetition period of the Pause data-bursts.8 Table 4 Data-type-dependent information for AC-4.9 Table 5 AC-4 base sampling frequency,AC-4 audio framerate and corresponding AC-4 data-burst repetition period.10 Table 6 AC-4 data-burst sequence and repetition period variance at 29,97,59,94 and 119,88 fps.10 Table 7 AC-4 data-burst:meaning of Pc bits 8 to 11 at an IEC 60958 frame rate of 48 kHz.11 Table 8 AC-4 data-burst:meaning of Pc bits 8 to 11 at an IEC 60958 frame rate of 44,1 kHz.11 Table 9 Maximum burst-length values per AC-4 data-burst repetition period.12 IEC 61937-14:2017 IEC 2017 3 Table 10 Data-type-dependent information for AC-4 HBR4.13 Table 11 AC-4 bas