ISO/IEC 23008-3:2019

INTERNATIONAL ISO/IEC
STANDARD 23008-3
Second edition
2019-02
Information technology — High
efficiency coding and media delivery
in heterogeneous environments —
Part 3:
3D audio
Technologies de l'information — Codage à haute efficacité et livraison
des medias dans des environnements hétérogènes —
Partie 3: Audio 3D
Reference number
©
ISO/IEC 2019
© ISO/IEC 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
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Email: copyright@iso.org
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Published in Switzerland
ii © ISO/IEC 2019 – All rights reserved

Contents Page
Foreword . x
Introduction . xii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols, abbreviations and mnemonics . 2
3.1 Terms, definitions, symbols and abbreviated terms . 2
3.2 Mnemonics . 2
4 Technical overview . 2
4.1 Decoder block diagram . 2
4.2 Overview over the codec building blocks . 3
4.3 Efficient combination of decoder processing blocks in the time domain and QMF domain . 6
4.4 Rule set for determining processing domains . 9
4.4.1 Audio core codec processing domain . 9
4.4.2 Mixing . 9
4.4.3 DRC-1 Operation domains (DRC in rendering context) . 10
4.4.4 Audio core codec interface domain to rendering . 10
4.4.5 Rendering context . 10
4.4.6 Post-processing context . 10
4.4.7 End-of-chain context . 11
4.5 Sample rate converter . 11
4.6 Decoder delay . 11
4.7 Contribution mode of MPEG-H 3D audio . 12
4.8 MPEG-H 3D audio profiles and levels . 12
4.8.1 General . 12
4.8.2 Profiles . 12
5 MPEG-H 3D audio core decoder . 22
5.1 Definitions . 22
5.1.1 Joint stereo . 22
5.1.2 MPEG surround based stereo (MPS 212) . 22
5.2 Syntax . 22
5.2.1 General . 22
5.2.2 Decoder configuration . 23
5.2.3 MPEG-H 3D audio core bitstream payloads . 41
5.3 Data structure . 60
5.3.1 General . 60
5.3.2 General configuration data elements . 61
5.3.3 Loudspeaker configuration data elements . 63
5.3.4 Core decoder configuration data elements . 65
5.3.5 Downmix matrix data elements . 69
5.3.6 HOA rendering matrix data elements . 72
5.3.7 Signal group information elements . 74
5.3.8 Low frequency enhancement (LFE) channel element, mpegh3daLfeElement() . 75
5.4 Configuration element descriptions . 75
5.4.1 General . 75
5.4.2 Downmix configuration . 76
5.4.3 HOA rendering matrix configuration . 81
5.5 Tool descriptions . 86
5.5.1 General . 86
5.5.2 Quad channel element . 86
5.5.3 Transform splitting . 88
© ISO/IEC 2019 – All rights reserved iii

5.5.4 MPEG surround for mono to stereo upmixing . 95
5.5.5 Enhanced noise filling . 97
5.5.6 Audio pre-roll . 121
5.5.7 Fullband LPD . 124
5.5.8 Time-domain bandwidth extension. 135
5.5.9 LPD stereo coding . 148
5.5.10 Multichannel coding tool . 155
5.5.11 Filterbank and block switching . 166
5.5.12 Frequency domain prediction . 166
5.5.13 Long-term postfilter . 169
5.5.14 Tonal component coding . 175
5.5.15 Internal channel on MPS212 for low complexity format conversion . 184
5.5.16 High resolution envelope processing (HREP) tool . 196
5.6 Buffer requirements . 202
5.6.1 Minimum decoder input buffer . 202
5.6.2 Bit reservoir . 203
5.6.3 Maximum bit rate . 203
5.7 Stream access point requirements and inter-frame dependency . 203
6 Dynamic range control and loudness processing . 205
6.1 General . 205
6.2 Description . 205
6.3 Syntax . 205
6.3.1 Loudness metadata . 205
6.3.2 Dynamic range control metadata. 205
6.3.3 Data elements . 206
6.4 Decoding process . 207
6.4.1 General . 207
6.4.2 Dynamic range control . 209
6.4.3 Usage of downmixId in MPEG-H . 209
6.4.4 DRC set selection process . 210
6.4.5 DRC-1 for SAOC 3D Content . 212
6.4.6 DRC-1 for HOA content . 212
6.4.7 Loudness normalization . 214
6.4.8 Peak limiter . 214
6.4.9 Time-synchronization of DRC gains . 214
6.4.10 Default parameters . 214
7 Object metadata decoding . 215
7.1 General . 215
7.2 Description . 215
7.3 Syntax . 216
7.3.1 Object metadata configuration . 216
7.3.2 Top level object metadata syntax . 217
7.3.3 Subsidiary payloads for efficient object metadata decoding . 218
7.3.4 Subsidiary payloads for object metadata decoding with low delay . 222
7.3.5 Enhanced object metadata configuration . 227
7.4 Data structure . 230
7.4.1 Definition of ObjectMetadataConfig() payloads . 230
7.4.2 Efficient object metadata decoding . 230
7.4.3 Object metadata decoding with low delay . 239
7.4.4 Enhanced object metadata . 244
8 Object rendering . 247
8.1 Description . 247
8.2 Terms and definitions . 247
8.3 Input data . 248
8.4 Processing . 249
8.4.1 General remark . 249
8.4.2 Imaginary loudspeakers . 249
8.4.3 Dividing the loudspeaker setup into a triangle mesh . 250
iv © ISO/IEC 2019 – All rights reserved

8.4.4 Rendering algorithm . 252
9 SAOC 3D . 256
9.1 Description . 256
9.2 Definitions . 256
9.3 Delay and synchronization . 258
9.4 Syntax . 258
9.4.1 Payloads for SAOC 3D . 258
9.4.2 Definition of SAOC 3D payloads . 262
9.5 SAOC 3D processing . 264
9.5.1 Compressed data stream decoding and dequantization of SAOC 3D data . 264
9.5.2 Time/frequency transforms . 264
9.5.3 Signals and parameters . 264
9.5.4 SAOC 3D decoding . 266
9.5.5 Dual mode . 271
10 Generic loudspeaker rendering/format conversion . 272
10.1 Description . 272
10.2 Definitions . 273
10.2.1 General remarks . 273
10.2.2 Variable definitions . 273
10.3 Processing . 274
10.3.1 Application of transmitted downmix matrices . 274
10.3.2 Application of transmitted equalizer settings . 278
10.3.3 Downmix processing involving multiple channel groups . 278
10.3.4 Initialization of the format converter. 279
10.3.5 Audio signal processing . 294
11 Immersive loudspeaker rendering/format conversion . 299
11.1 Description . 299
11.2 Syntax . 301
11.3 Definitions . 301
11.3.1 General remarks . 301
11.3.2 Variable definitions . 302
11.4 Processing . 303
11.4.1 Initialization of the format converter. 303
11.4.2 Audio signal processing . 343
12 Higher order ambisonics (HOA) . 350
12.1 Technical overview . 350
12.1.1 Block diagram . 350
12.1.2 Overview of the decoder tools . 351
12.2 Syntax . 353
12.2.1 Configuration of HOA elements . 353
12.2.2 Payloads of HOA elements . 356
12.3 Data structure . 368
12.3.1 Definitions of HOA Config . 368
12.3.2 Syntax of getSubbandBandwidths() . 373
12.3.3 Definitions of HOA payload . 373
12.4 HOA tool description . 381
12.4.1 HOA frame converter . 381
12.4.2 Spatial HOA decoding . 398
12.4.3 HOA renderer . 428
12.4.4 Layered coding for HOA . 436
13 Binaural renderer . 439
13.1 General . 439
13.2 Frequency-domain binaural renderer . 439
13.2.1 General . 439
13.2.2 Definitions . 441
13.2.3 Parameterization of binaural room impulse responses . 445
13.2.4 Frequency-domain binaural processing . 457
© ISO/IEC 2019 – All rights reserved v

13.3 Time-domain binaural renderer . 464
13.3.1 General . 464
13.3.2 Definitions . 465
13.3.3 Parameterization of binaural room impulse responses . 467
13.3.4 Time-domain binaural processing . 471
14 MPEG-H 3D audio stream (MHAS) . 472
14.1 Overview . 472
14.2 Syntax . 472
14.2.1 Main MHAS syntax elements . 472
14.2.2 Subsidiary MHAS syntax elements . 474
14.3 Semantics . 475
14.3.1 mpeghAudioStreamPacket() . 475
14.3.2 MHASPacketPayload() . 475
14.3.3 Subsidiary MHAS packets . 477
14.4 Description of MHASPacketTypes . 477
14.4.1 PACTYP_FILLDATA . 477
14.4.2 PACTYP_MPEGH3DACFG. 477
14.4.3 PACTYP_MPEGH3DAFRAME . 477
14.4.4 PACTYP_SYNC . 478
14.4.5 PACTYP_SYNCGAP . 478
14.4.6 PACTYP_MARKER . 478
14.4.7 PACTYP_CRC16 and PACTYP_CRC32 . 479
14.4.8 PACTYP_DESCRIPTOR . 479
14.4.9 PACTYP_USERINTERACTION . 479
14.4.10 PACTYP_LOUDNESS_DRC . 479
14.4.11 PACTYP_BUFFERINFO . 479
14.4.12 PACTYP_GLOBAL_CRC16 and PACTYP_ GLOBAL_CRC32 . 480
14.4.13 PACTYP_AUDIOTRUNCATION . 480
14.4.14 PACTYP_AUDIOSCENEINFO . 481
14.5 Application examples . 481
14.5.1 Light-weighted broadcast . 481
14.5.2 MPEG-2 transport stream . 482
14.5.3 CRC error detection . 482
14.5.4 Audio sample truncation . 483
14.6 Multi-stream delivery and interface . 483
14.7 Carriage of generic data . 486
14.7.1 Syntax . 486
14.7.2 Semantics . 487
14.7.3 Processing at the MPEG-H 3D audio decoder . 487
15 Metadata audio elements (MAE) . 488
15.1 General . 488
15.2 Syntax . 489
15.3 Semantics . 496
15.4 Definition of mae_metaDataElementIDs . 509
15.5 Loudness compensation after gain interactivity . 510
16 Loudspeaker distance compensation . 512
17 Interfaces to the MPEG-H 3D audio decoder . 513
17.1 General . 513
17.2 Interface for local setup information . 513
17.2.1 General . 513
17.2.2 WIRE output . 513
17.2.3 Syntax for local setup information . 514
17.2.4 Semantics for local setup information . 514
17.3 Interface for local loudspeaker setup and rendering . 514
17.3.1 General . 514
17.3.2 Syntax for local loudspeaker signalling . 515
17.3.3 Semantics for local loudspeaker signalling . 516
vi © ISO/IEC 2019 – All rights reserved

17.4 Interface for binaural room impulse responses (BRIRs) . 517
17.4.1 General . 517
17.4.2 Syntax of binaural renderer interface . 517
17.4.3 Semantics . 521
17.5 Interface for local screen size information . 525
17.5.1 General . 525
17.5.2 Syntax . 525
17.5.3 Semantics . 525
17.6 Interface for signaling of local zoom area . 526
17.6.1 General . 526
17.6.2 Syntax . 526
17.6.3 Semantics . 526
17.7 Interface for user interaction . 527
17.7.1 General . 527
17.7.2 Definition of user interaction categories . 527
17.7.3 Definition of an interface for user interaction . 527
17.7.4 Syntax of interaction interface . 528
17.7.5 Semantics of interaction interface . 529
17.8 Interface for loudness normalization and dynamic range control (DRC) . 531
17.9 Interface for scene displacement data . 532
17.9.1 General . 532
17.9.2 Definition of an interface for scene-displacement data . 532
17.9.3 Syntax of the scene displacement interface . 533
17.9.4 Semantics of the scene displacement interface . 533
17.10 Interfaces for channel-based, object-based, and HOA metadata and audio data . 534
17.10.1 General . 534
17.10.2 Expectations on external renderers . 534
17.10.3 Object-based metadata and audio data (object output interface) . 534
17.10.4 Channel-based metadata and audio data . 540
17.10.5 HOA metadata and audio data . 543
17.10.6 Audio PCM data . 545
18 Application and processing of local setup information and interaction data and scene
displacement data . 546
18.1 Element metadata preprocessing . 546
18.2 Interactivity limitations and restrictions . 551
18.2.1 General information . 551
18.2.2 WIRE interactivity . 551
18.2.3 Position interactivity. 552
18.2.4 Screen-related element remapping and object remapping for zooming . 552
18.2.5 Closest loudspeaker playout . 553
18.3 Screen-related element remapping . 553
18.4 Screen-related adaptation and zooming for higher order ambisonics (HOA) . 556
18.5 Object remapping for zooming . 557
18.6 Determination of the closest loudspeaker . 558
18.7 Determination of a list of loudspeakers for conditioned closest loudspeaker playback. 559
18.8 Processing of scene displacement angles for channels and objects (CO) . 561
18.9 Processing of scene displacement angles for scene-based content (HOA) . 562
18.10 Determination of a reduced reproduction layout based on excluded sectors . 564
18.11 Diffuseness rendering . 565
19 MPEG-H 3D audio profile definition . 566
20 Carriage of MPEG-H 3D audio in ISO base media file format . 567
20.1 General . 567
20.2 Random access and stream access . 567
20.3 Overview of new box structures . 567
20.4 MHA decoder configuration record . 567
20.4.1 Definition . 567
20.4.2 Syntax . 568
20.4.3 Semantics . 568
© ISO/IEC 2019 – All rights reserved vii

20.5 MPEG-H audio sample entry . 568
20.5.1 Definition . 568
20.5.2 Syntax . 569
20.5.3 Semantics . 569
20.6 MPEG-H audio MHAS sample entry . 570
20.6.1 Definition . 570
20.6.2 Syntax . 571
20.7 MHA dynamic range control and loudness .
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