ISO/IEC 23090-2:2019

INTERNATIONAL ISO/IEC
STANDARD 23090-2
First edition
2019-01
Information technology — Coded
representation of immersive media —
Part 2:
Omnidirectional media format
Technologies de l'information — Représentation codée de média
immersifs — Partie 2: Format de média omnidirectionnel
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
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Published in Switzerland
ii © ISO/IEC 2019 – All rights reserved

Contents
Foreword . vii
Introduction . viii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, abbreviated terms, and conventions . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 6
3.3 Arithmetic operators and mathematical functions . 7
3.4 Order of operation precedence . 8
3.5 Range notation . 9
3.6 Variables . 9
3.7 Processes . 9
4 Overview . 9
4.1 Organization of this document . 9
4.2 Overall architecture for omnidirectional media with projected video . 10
4.2.1 Overview . 10
4.2.2 Stitching, rotation, projection, and region-wise packing . 11
4.3 Overall architecture for omnidirectional media with fisheye video . 12
4.4 Conformance and interoperability . 13
4.4.1 General . 13
4.4.2 Media profiles . 14
4.4.3 Presentation profiles . 15
4.4.4 Summary of referenceable code points . 16
5 Omnidirectional video projection and region-wise packing . 19
5.1 Coordinate system . 19
5.2 Omnidirectional projection formats . 20
5.2.1 General . 20
5.2.2 Equirectangular projection for one sample location . 20
5.2.3 Cubemap projection for one sample location . 21
5.3 Conversion from the local coordinate axes to the global coordinate axes . 23
5.4 Region-wise packing formats . 24
5.4.1 General . 24
5.4.2 Conversion of one sample location for rectangular region-wise packing . 24
6 Fisheye omnidirectional video . 25
6.1 General . 25
6.2 FisheyeVideoEssentialInfoStruct syntax structure . 26
6.2.1 Syntax . 26
6.2.2 Semantics . 26
6.3 FisheyeVideoSupplementalInfoStruct syntax structure . 29
6.3.1 Syntax . 29
© ISO/IEC 2019 – All rights reserved iii

6.3.2 Semantics . 30
7 Omnidirectional media storage and metadata signalling in the ISOBMFF . 33
7.1 Generic extensions to the ISOBMFF . 33
7.1.1 Stereoscopic video track grouping . 33
7.1.2 Indication of track_group_id uniqueness . 34
7.1.3 Updated semantics of track_IDs of the track reference box . 34
7.1.4 Indication of a track not intended to be presented alone . 34
7.1.5 Timed metadata tracks . 34
7.1.6 Compatible scheme type box . 35
7.1.7 Multiple transformations for a single transformed media track . 35
7.1.8 The 'codecs' parameter for a transformed media track . 35
7.1.9 Track type box . 36
7.1.10 Clarifications on the stereo video box . 36
7.2 Generic extensions to ISO/IEC 14496-15 . 37
7.2.1 Alternative extraction source track grouping . 37
7.2.2 Tile base track association with coverage information box and timed metadata data track . 37
7.3 OMAF-specific extensions to the ISOBMFF . 37
7.3.1 Sync samples in timed metadata tracks . 37
7.4 OMAF-specific extensions to ISO/IEC 14496-15 . 37
7.4.1 Coverage information box in a tile base track . 37
7.5 Structures and semantics that are common for video tracks and image items . 38
7.5.1 Semantics of sample locations within a decoded picture . 38
7.5.2 Projection format structure . 41
7.5.3 Region-wise packing structure . 41
7.5.4 Rotation structure . 48
7.5.5 Content coverage structure . 48
7.5.6 Sphere region structure . 49
7.6 Restricted video schemes for omnidirectional video . 51
7.6.1 Scheme types. 51
7.6.2 Projected omnidirectional video box . 54
7.6.3 Fisheye omnidirectional video box . 55
7.6.4 Region-wise packing box . 55
7.6.5 Rotation box . 56
7.6.6 Coverage information box . 56
7.7 Timed metadata for sphere regions . 56
7.7.1 General . 56
7.7.2 Sample entry . 57
7.7.3 Sample format . 58
7.7.4 Initial viewing orientation . 58
7.7.5 Recommended viewport . 59
7.7.6 Timed text sphere location metadata . 60
7.8 Signalling of region-wise quality ranking . 61
7.8.1 General . 61
7.8.2 Spherical region-wise quality ranking . 61
7.8.3 2D region-wise quality ranking . 63
7.9 Storage of omnidirectional images . 65
7.9.1 General . 65
7.9.2 Frame packing item property . 65
7.9.3 Projection format item property . 65
7.9.4 Essential fisheye image item property. 66
7.9.5 Supplemental fisheye image item property . 67
7.9.6 Region-wise packing item property . 67
7.9.7 Rotation item property . 68
iv © ISO/IEC 2019 – All rights reserved

7.9.8 Coverage information item property. 68
7.9.9 Initial viewing orientation item property . 69
7.10 Storage of timed text for omnidirectional video . 69
7.10.1 General . 69
7.10.2 OMAF timed text configuration box . 70
7.10.3 IMSC1 tracks . 72
7.10.4 WebVTT tracks . 73
8 Omnidirectional media encapsulation and signalling in DASH . 73
8.1 Architecture of DASH delivery in OMAF . 73
8.2 Usage of DASH in OMAF . 74
8.2.1 General . 74
8.2.2 Signalling of stereoscopic frame packing . 74
8.2.3 Carriage of timed metadata . 74
8.3 DASH MPD descriptors for omnidirectional media . 75
8.3.1 XML namespace and schema . 75
8.3.2 Signalling of projection type information . 75
8.3.3 Signalling of region-wise packing type . 76
8.3.4 Signalling of content coverage . 76
8.3.5 Signalling of spherical region-wise quality ranking . 79
8.3.6 Signalling of 2D region-wise quality ranking . 84
8.3.7 Signalling of fisheye omnidirectional video . 88
9 Omnidirectional media encapsulation and signalling in MMT . 89
9.1 Architecture of MMT delivery in OMAF . 89
9.2 OMAF signalling in MPEG composition information . 90
9.3 VR application-specific MMT signalling . 90
9.3.1 General . 90
9.3.2 MMT signalling . 91
10 Media profiles . 103
10.1 Video profiles . 103
10.1.1 Overview . 103
10.1.2 HEVC-based viewport-independent OMAF video profile . 103
10.1.3 HEVC-based viewport-dependent OMAF video profile . 106
10.1.4 AVC-based viewport-dependent OMAF video profile . 109
10.2 Audio profiles . 111
10.2.1 Overview . 111
10.2.2 OMAF 3D audio baseline profile . 111
10.2.3 OMAF 2D audio legacy profile . 114
10.3 Image profiles . 118
10.3.1 Overview . 118
10.3.2 Common specifications for image profiles . 119
10.3.3 OMAF HEVC image profile . 120
10.3.4 OMAF legacy image profile . 121
10.4 Timed text profiles . 122
10.4.1 Overview . 122
10.4.2 OMAF IMSC1 timed text profile . 123
10.4.3 OMAF WebVTT timed text profile . 123
11 Presentation profiles . 124
11.1 OMAF viewport-independent baseline presentation profile . 124
11.1.1 General (informative) . 124
© ISO/IEC 2019 – All rights reserved v

11.1.2 ISO base media file format constraints . 124
11.2 OMAF viewport-dependent baseline presentation profile . 124
11.2.1 General . 124
11.2.2 ISO base media file format constraints . 124
Annex A (normative) OMAF DASH schema . 125
Annex B (normative) DASH integration of media profiles . 128
Annex C (normative) CMAF integration of media profiles . 134
Annex D (informative) Viewport-dependent omnidirectional video processing . 136
Annex E (informative) DASH MPD examples . 154
Annex F (informative) MMT signalling examples . 158

vi © ISO/IEC 2019 – All rights reserved

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form
the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established by the respective organization to deal
with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.
In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC
Directives, Part 1. In particular the different approval criteria needed for the different types of document should be noted.
This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2
(see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO
and IEC shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified
during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received
(see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not constitute an
endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to
conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles
in the Technical Barriers to Trade (TBT) see: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29,
Coding of audio, picture, multimedia and hypermedia information.
A list of all parts in the ISO/IEC 23090 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing
of these bodies can be found at www.iso.org/members.html.
© ISO/IEC 2019 – All rights reserved vii

Introduction
When omnidirectional media content is consumed with a head-mounted display and headphones, only the parts of the
media that correspond to the user's viewing orientation are rendered, as if the user were in the spot where and when the
media was captured. One of the most popular forms of omnidirectional media applications is omnidirectional video, also
known as 360° video. Omnidirectional video is typically captured by multiple cameras that cover up to 360° of the scene.
Compared to traditional media application formats, the end-to-end technology for omnidirectional video (from capture to
playback) is more easily fragmented due to various capturing and video projection technologies. From the capture side,
there exist many different types of cameras capable of capturing 360° video, and on the playback side there are many
different devices that are able to playback 360° video with different processing capabilities. To avoid fragmentation of
omnidirectional media content and devices, a standardized format for omnidirectional media applications is specified in
this document.
This document defines a media format that enables omnidirectional media applications, focusing on 360° video, images,
and audio, as well as associated timed text. What is specified in this document includes (but is not limited to):
1) a coordinate system that consists of a unit sphere and three coordinate axes, namely the X (back-to-front) axis, the Y
(lateral, side-to-side) axis, and the Z (vertical, up) axis,
2) projection and rectangular region-wise packing methods that may be used for conversion of a spherical video sequence
or image into a two-dimensional rectangular video sequence or image, respectively,
3) storage of omnidirectional media and the associated metadata using the ISO base media file format (ISOBMFF) as
specified in ISO/IEC 14496-12,
4) encapsulation, signalling, and streaming of omnidirectional media in a media streaming system, e.g., dynamic
adaptive streaming over HTTP (DASH) as specified in ISO/IEC 23009-1 or MPEG media transport (MMT) as
specified in ISO/IEC 23008-1, and
5) media profiles and presentation profiles that provide interoperable and conformance points for media codecs as well
as media coding and encapsulation configurations that may be used for compression, streaming, and playback of the
omnidirectional media content.

viii © ISO/IEC 2019 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 23090-2:2019(E)

Information technology — Coded representation of immersive
media —
Part2:
Omnidirectional media format
1 Scope
This document specifies the omnidirectional media format for coding, storage, delivery, and rendering of omnidirectional
media, including video, images, audio, and timed text.
In an OMAF player the user's viewing perspective is from the centre of the sphere looking outward towards the inside
surface of the sphere.
NOTE 1 In this document, only 3 degrees of freedom (3DOF) is supported. In other words, purely translational movement of the user
does not result in different omnidirectional media being rendered to the user. For 3DOF support with stereoscopic video, when the user
rolls his/her head, there could be a stereoscopic rendering issue.
NOTE 2 Omnidirectional video could contain graphics elements generated by computer graphics but encoded as video.
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 document. For dated references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
ISO/IEC 10918-1, Information technology — Digital compression and coding of continuous-tone still images — Part 1:
Requirements and guidelines
ISO/IEC 14496-1, Infomation technology — Coding of audio-visual objects — Part 1: Systems
ISO/IEC 14496-3:2009, Information technology — Coding of audio-visual objects — Part 3: Audio
ISO/IEC 14496-10:2014, Information technology — Coding of audio-visual objects — Part 10: Advanced video coding
ISO/IEC 14496-12, Information technology — Coding of audio-visual objects — Part 12: ISO base media file format
ISO/IEC 14496-14, Information technology — Coding of audio-visual objects — Part 14, MP4 file format
ISO/IEC 14496-15:2017, Information technology — Coding of audio-visual objects — Part 15, Carriage of network
abstraction layer (NAL) unit structured video in the ISO base media file format
ISO/IEC 14496-30:2018, Information technology — Coding of audio-visual objects — Part 30: Timed text and other
visual overlays in ISO base media file format
ISO/IEC 23000-19:2018, Information technology — Multimedia application format (MPEG-A) — Part 19: Common
media application format (CMAF) for segmented media
ISO/IEC 23003-4:2015, Information technology — MPEG audio technologies — Part 4: Dynamic range control
ISO/IEC 23008-1:2017, Information technology — High efficiency coding and media delivery in heterogeneous
environments — Part 1: MPEG media transport (MMT)
ISO/IEC 23008-2:2017, Information technology — High efficiency coding and media delivery in heterogeneous
environments — Part 2: High efficiency video coding
ISO/IEC 23008-3:2015, Information technology — High efficiency coding and media delivery in heterogeneous
environments — Part 3: 3D audio
© ISO/IEC 2019 – All rights reserved 1

ISO/IEC 23008-12, Information technology — High efficiency coding and media delivery in heterogeneous
environments — Part 12: Image file format
ISO/IEC 23009-1, Information technology — Dynamic adaptive streaming over HTTP (DASH) — Part 1: Media
presentation description and segment formats
ISO/IEC 23091-2 , Information technology — Coding-independent code points — Part 2: Video
ISO/IEC 23091-3, Information technology — Coding-independent code points — Part 3: Audio
W3C Recommendation, TTML profiles for Internet media subtitles and captions 1.0 (IMSC1)
WebVTT: The web video text tracks format, W3C (Working Draft, 08 August 2017)
W3C Recommendation, XML schema part 1: Structures
W3C Recommendation, XML schema part 2: Datatypes
IETF BCP 47, Tags for Identifying Languages
IETF RFC 6381, MIME Codecs and Profiles
3 Terms, definitions, abbreviated terms, and conventions
3.1 Terms and definitions
For the purposes of this document, the terms and definitions in ISO/IEC 14496-12, ISO/IEC 23008-12, ISO/IEC 23009-1
and the following apply. If terms defined in ISO/IEC 14496-12, ISO/IEC 23008-12 and ISO/IEC 23009-1 are also defined
in this document, the definitions in this document are applicable.
NOTE In particular, the terms coded image, coded image item, derived image, derived image item, image item, reconstructed image,
and source image item are defined in ISO/IEC 23008-12.
The terminological databases for use in standardization maintained by ISO and IEC at the following addresses:
− IEC Electropedia: available at http://www.electropedia.org/
− ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
azimuth
first of the two sphere coordinates describing the location of a point on the sphere
Note 1 to entry: Azimuth and elevation are specified in subclause 5.1.
3.1.2
azimuth circle
circle on the sphere connecting all points with the same azimuth value
Note 1 to entry: An azimuth circle is always a great circle (3.1.17).
3.1.3
circular image
image captured with a fisheye lens (3.1.14)
3.1.4
closed scheme type
scheme type (3.1.35) that clearly specifies which transformations are allowed and does not allow future extensions

Under preparation. Stage at time of FDIS ballot: ISO/IEC DIS 23091-2, 40.99.
2 © ISO/IEC 2019 – All rights reserved

3.1.5
composition-aligned sample
sample in a track that is associated with another track, the sample has the same composition time as a particular sample in
the another track, or, when a sample with the same composition time is not available in the another track, the closest
preceding composition time relative to that of a particular sample in the another track
3.1.6
constituent picture
such part of a spatially frame-packed stereoscopic picture that corresponds to one view, or a picture itself when frame
packing is not in use or the temporal interleaving frame packing arrangement is in use
3.1.7
content coverage
one or more sphere regions that are covered by the content represented by the track or by an image item
3.1.8
elevation
second of the two sphere coordinates describing the location of a point on the sphere
Note 1 to entry: Azimuth and elevation are specified in subclause 5.1.
3.1.9
elevation circle
circle on the sphere connecting all points with the same elevation value
Note 1 to entry: When the elevation is zero, an elevation circle is also a great circle (3.1.17). This coincides with the equator on Earth.
3.1.10
extractor track
track that has untransformed sample entry type (3.1.44) equal to 'hvc2', 'avc2', or 'avc4' and contains one or more
'scal' track references
3.1.11
field of view
extent of the observable world in captured/recorded content or in a physical display device
3.1.12
file decoder
collective term for file/segment decapsulation and decoding of video, audio or image bitstreams
3.1.13
file decoding process
process specified as a part of a media profile specification that takes as input a set of ISOBMFF tracks or items and derives
either of the following:
− decoded pictures or audio samples, and rendering metadata for them;
− a fully rendered audio scene in the reference system
3.1.14
fisheye lens
wide-angle camera lens that usually captures an approximately hemispherical field of view (3.1.11) and projects it as a
circular image (3.1.3)
3.1.15
fisheye video
video captured by fisheye lenses (3.1.14)
3.1.16
global coordinate axes
coordinate axes that are associated with audio, video, and images representing the same acquisition position and intended
to be rendered together
Note 1 to entry: Coordinate axes are specified in subclause 5.1.
© ISO/IEC 2019 – All rights reserved 3

Note 2 to entry: The origin of the global coordinate axes is usually the same as the centre point of a device or rig used for omnidirectional
audio/video acquisition as well as the position of the observer's head in the three-dimensional space in which the audio and video tracks
are located.
Note 3 to entry: In the absence of the initial viewing orientation metadata (see subclause 7.7.4 for tracks or subclause 7.9.9 for image
items), the initial viewing orientation should be inferred to be equal to (0, 0, 0) for (centre_azimuth, centre_elevation,
centre_tilt) relative to the global coordinate axes.
3.1.17
great circle
intersection of the sphere and a plane that passes through the centre point of the sphere
Note 1 to entry: A great circle is also known as an orthodrome or Riemannian circle.
Note 2 to entry: The centre of the sphere and the centre of a great circle are co-located.
3.1.18
guard band
area in a packed picture (3.1.23) that is not rendered but may be used to improve the rendered part of the packed picture to
avoid or mitigate visual artifacts such as seams
Note to entry: Guard bands are associated with packed regions (3.1.24) as described in subclause 7.5.3.
3.1.19
local coordinate axes
coordinate axes obtained after applying rotation to the global coordinate axes (3.1.16)
3.1.20
OMAF player
collective term for
− file/segment reception or file access;
− file/segment decapsulation;
− decoding of audio, video, image, or timed text bitstreams;
− rendering of audio, images, or timed text; and
− viewport selection
3.1.21
omnidirectional media
media such as image or video and its associated audio that enable rendering according to the user's viewing orientation
(3.1.45), if consumed with a head-mounted device, or according to user's desired viewport (3.1.46), otherwise, as if the
user was in the spot where and when the media was captured
3.1.22
open-ended scheme type
scheme type (3.1.35) that allows future extensions
3.1.23
packed picture
picture that is represented as a coded picture in the coded video bitstream
Note 1 to entry: A packed picture may result from region-wise packing (3.1.31) of a projected picture (3.1.25).
3.1.24
packed region
region in a packed picture (3.1.24) that is mapped to a projected region (3.1.26) as specified by the region-wise packing
(3.1.31) signalling
3.1.25
projected picture
picture that has a representation format specified by an omnidirectional video projection format
Note 1 to entry: Omnidirectional projection formats are specified in subclause 5.2.
4 © ISO/IEC 2019 – All rights reserved

3.1.26
projected region
region in a projected picture (3.1.25) that is mapped to a packed region (3.1.24) as specified by the region-wise packing
signalling
3.1.27
projection
inverse of the process by which the samples of a projected picture (3.1.25) are mapped to a set of positions identified by a
set of azimuth and elevation coordinates on a unit sphere
3.1.28
quality ranking region
region that is associated with a quality ranking value and is specified relative to a decoded picture or a sphere
3.1.29
quality ranking 2D region
quality ranking region (3.1.28) that is specified relative to a decoded picture
3.1.30
quality ranking sphere region
quality ranking region (3.1.28) that is specified relative to a sphere
3.1.31
region-wise packing
inverse of the process of transformation, resizing, and relocating of packed regions (3.1.24) of a packed picture (3.1.23) to
remap to projected regions (3.1.26) of a projected picture (3.1.25)
3.1.32
rendering
process of generating audio-visual content for playback from the decoded audio-visual data according to the user's viewing
orientation (3.1.45), if consumed with a head-mounted device, or according to user's desired viewport (3.1.46), otherwise
3.1.33
sample
all the data associated with a single time or single element in one of the three sample arrays that represent a picture
Note 1 to entry: When the term sample is used in the context of a track, it refers to all the data associated with a single time of that track,
where a time is either a decoding time or a composition time. When the term sample is used in the context of a picture, e.g., in the phrase
"luma sample", it refers to a single element in one of the three sample arrays that represent the picture.
3.1.34
sample entry type
four-character code that is either the value of the format field of a SampleEntry directly contained in
SampleDescriptionBox or the data_format value of an instance of OriginalFormatBox
3.1.35
scheme type
type that parameterizes an encrypted, restricted, or incomplete media track
3.1.36
sphere coordinates
azimuth (ϕ) and elevation (θ) that identify a location of a point on the unit sphere
3.1.37
sphere region
region on a sphere, specified either by four great circles (3.1.17) or by two azimuth circles (3.1.2) and two elevation circles
(3.1.9), or such a region on the rotated sphere after applying certain amount of yaw, pitch, and roll rotations
3.1.38
sub-picture
picture that represents a spatial subset of the original video content, which has been split into spatial subsets before video
encoding at the content production side
© ISO/IEC 2019 – All rights reserved 5

3.1.39
sub-picture bitstream
bitstream that represents a spatial subset of the original video content, which has been split into spatial subsets before video
encoding at the content production side
3.1.40
sub-picture track
track that represents a sub-picture bitstream (3.1.39)
3.1.41
tilt angle
angle indicating the amount of tilt of a sphere region (3.1.37), measured as the amount of rotation of the sphere region
along the axis originating from the sphere origin passing through the centre point of the sphere region, where the angle
value increases clockwise when looking from the origin towards the positive end of the axis
3.1.42
time-parallel sample
sample in a track that is associated with another track, and either has the same decoding time as a particular sample in the
other track, or, when a sample with the same decoding time in the other track is not available, the closest preceding decoding
time relative to that of a particular sample in the other track
3.1.43
track sample entry type
sample entry type (3.1.34) of a SampleEntry directly contained in SampleDescriptionBox
3.1.44
untransformed sample entry type
track sample entry type (3.1.43) that would apply if no transformations had been performed to a transformed media track
3.1.45
viewing orientation
triplet of azimuth, elevation, and tilt angle characterizing the orientation that a user is consuming the audio-visual content;
in case of image or video, characterizing the orientation of the viewport (3.1.46)
3.1.46
viewport
region of omnidirectional image or video suitable for display and viewing by the user
3.2 Abbreviated terms
2D two-dimensional
CICP coding-independent code points (specified in ISO/IEC 23091-1, 23091-2, and 23091-3)
CMAF common media application format (specified in ISO/IEC 23000-19)
DASH MPEG dynamic adaptive streaming over HTTP (specified in ISO/IEC 23009-1)
ERP equirectangular projection
FOV field of view
ISOBMFF ISO base media file format (specified in ISO/IEC 14496-12)
HEVC high efficiency video coding (specified in ISO/IEC 23008-2)
HMD head-mounted display
HOA higher-order ambisonics
6 © ISO/IEC 2019 – All rights reserved

MCTS motion-constrained tile set
MMT MPEG media transport (specified in ISO/IEC 23008-1)
OMAF omnidirectional media format (specified in ISO/IEC 23090-2)
SRD spatial relationship description
URN uniform resource name
VR virtual reality
3.3 Arithmetic operators and mathematical functions
+ addition
− subtraction (as a two-argument operator) or negation (as a unary prefix operator)
* multiplication, including matrix multiplication
y
x exponentiation, specifies x to the power of y
(In other contexts, such notation is used for superscripting not intended for interpretation as exponentiation.)
/ integer division with truncation of the result toward zero
EXAMPLE 7 / 4 and −7 / −4 are truncated to 1 and −7 / 4 and 7 / −4 are truncated to −1.
÷ denotes division in mathematical equations where no truncation or rounding is intended
x
denotes division in mathematical equations where no truncation or rounding is intended
y
y
f (i)
summation of f( i ) with i taking all integer values from x up to and including y
∑
i=x
x % y modulus
(Remainder of x divided by y, defined only for integers x and y with x >= 0 and y > 0.)
Asin( x ) trigonometric inverse sine function, operating on an argument x that is in the range of −1.0 to 1.0, inclusive,
with an output value in the range of −π÷2 to π÷2, inclusive, in units of radians
Atan( x ) trigonometric invers tangent function, operating on an argument x that is any real number, with an output value
in the range of −π÷2 to π÷2, inclusive, in units of radians
  y
Atan ; if x > 0
 

x
 

y
 

Atan +π ; if x < 0 & & y >= 0

x
 


 y
Atan2( y, x ) =

Atan −π ; if x < 0 & & y < 0
 
 x
 

π
+ ; if x == 0 & & y >= 0


π

− ; otherwise


Cos( x ) trigonometric cosine function operating on an argument x in units of radians
© ISO/IEC 2019 – All rights reserved 7

Floor( x ) largest integer less than or equal to x
Round( x ) = Sign( x ) * Floor(
...