1、 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,Sw
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11、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
12、 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 dat
13、a-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
14、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
15、 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
16、 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
