1、Information technology Dynamic adaptive streaming over HTTP (DASH) Part 1: Media presentation description and segment formats AMENDMENT 2: Spatial relationship description, generalized URL parameters and other extensions Technologies de linformation Diffusion en flux adaptatif dynamique sur HTTP (DA
2、SH) Partie 1: Description de la prsentation et formats de remise des mdias AMENDEMENT 2: Description des relations spatiales, paramtres URL gnraliss et autres extensions INTERNATIONAL STANDARD ISO/IEC 23009-1 Second edition 2014-05-15 Reference number ISO/IEC 23009-1:2014/Amd.2:2015(E) AMENDMENT 2 2
3、015-07- 01 ISO/IEC 2015 ii ISO/IEC 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical,
4、including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerl
5、and Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO/IEC 23009-1:2014/Amd.2:2015(E)ISO/IEC 23009-1:2014/Amd 2:2015(E) ISO/IEC 2015 All rights reserved iiiContents Page Foreword iv Introduction . v Annex H (normative) Spatial Relationship Descriptions . 5 H.1 Spatial Relati
6、onship Description (SRD) scheme 5 H.2 SRD value syntax . 5 H.3 Examples 7 H.3.1 Zoomed video 7 H.3.2 Tiled video 8 Annex I (normative) Flexible Insertion of URL Parameters 10 I.1 Introduction 10 I.2 Syntax . 10 I.2.1 URL Query Information . 11 I.2.4 Examples 14 ISO/IEC 23009-1:2014/Amd 2:2015(E) iv
7、ISO/IEC 2015 All rights reservedForeword 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 Intern
8、ational 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
9、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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint technica
10、l committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is draw
11、n 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. Amendment 2 to ISO/IEC 23009-1:2015 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information Techn
12、ology, Subcommittee SC 29, Coding of Audio, Picture, Multimedia and Hypermedia Information. ISO/IEC 23009-1:2014/Amd 2:2015(E) ISO/IEC 2015 All rights reserved vIntroduction This amendment to ISO/IEC 23009-1 adds the ability for MPD authors to express: - Spatial Relationship Description between Spat
13、ial Objects in the MPD; - Flexible parameter insertions in URLs used to query Media Segments; - Additional Role values; - Association between Representations FINAL DRAFT AMENDMENT ISO/IEC 23009-1:2014/Amd 2:2015(E) ISO/IEC 2015 All rights reserved 1Information Technology Dynamic adaptive streaming o
14、ver HTTP (DASH) Part 1: Spatial Relationship Description, Generalized URL parameters and other extensions In clause 2 “Normative references“, add the following reference, in alphabetical order: HTML 4.01 Specification, W3C Recommendation, 24 December1999 In clause 3.1 “Terms and definitions“, add th
15、e following definitions in alphabetical order: 3.1.X associated Representation Representation which provides supplemental or descriptive information for at least one other Representation 3.1.X Spatial Object a media content component corresponding to a region in a coordinate system associated to thi
16、s media content component In clause 3.2 “Symbols and abbreviated terms”, add the following term: SRD Spatial Relationship Description In clause 4.7 “Schemes”, Table 2, add the following identifiers: Scheme Identifier Clause in this part of ISO/IEC 23009 Informative description urn:mpeg:dash:srd:2014
17、 H.1 Scheme identifier for Spatial Relationship Description urn:mpeg:dash:urlparam:2014 I.1 Scheme identifier for indicating usage of the flexible insertion of URL query parameters urn:mpeg:dash:audio-receiver- mix:2014 5.8.5.7 Scheme identifier for receiver mix In clause 5.3.5.1 “Overview“, add : “
18、Associated Representations are described by a Representation element that contains an associationId attribute and optionally an associationType attribute. Associated Representations are Representations that provide information on their relationships with other Representations. As opposed to compleme
19、ntary Representations, the segments of an associated Representation may be optional for decoding ISO/IEC 23009-1:2014/Amd 2:2015(E) 2 ISO/IEC 2015 All rights reservedand/or presentation of the Representations identified by associationId. They can be considered as supplementary or descriptive informa
20、tion, the type of the association being specified by the associationType attribute“ In clause 5.3.5.2 “Representation Semantics”, Table 7 Semantics of Representation element, add: associationId O specifies all Representations the Representation is associated with in the decoding and/or presentation
21、process as a whitespace-separated list of values of Representationid attributes. associationType O specifies, as a whitespace separated list of values, the kind of association for each Representation the Representation has been associated with through the associationId attribute. Values taken by thi
22、s attribute are 4 character codes for track reference types registered in MP4 registration authority. This attribute shall not be present when associationId is not present. When present, this attribute must have as many values as the number of identifiers declared in the associationId attribute NOTE
23、 - associationId and associationType attributes can only be used between Representations that are not in the same Adaptation Sets. In clause 5.8.5.5 “DASH Role scheme”, Table 22, add the following rows: description Textual or audio media component containing a textual description (intended for audio
24、 synthesis) or an audio description describing a visual component sign Visual media component representing a sign-language interpretation of an audio component. metadata Media component containing information intended to be processed by application specific elements. enhanced-audio- intelligibility
25、Audio component with improved intelligibility of the dialogue In clause 5.8.5.5 “DASH Role scheme”, in Table 22, add the following note: 4) Role descriptors with values such as “subtitle“, “caption“, “description“, “sign“ or “metadata“ may be used to enable assignment of a “kind“ value in HTML 5 app
26、lications for tracks exposed from a DASH MPD. Add the following to the end of clause 5.8.5 ISO/IEC 23009-1:2014/Amd 2:2015(E) ISO/IEC 2015 All rights reserved 35.8.5.7 Audio Receiver Mix This clause defines a scheme for use in EssentialProperty or SupplementaryProperty to indicate that two audio Ada
27、ptation Sets need to be mixed by the media engine prior to playback. The schemeIdUri attribute identifying the scheme is urn:mpeg:dash:audio-receiver-mix:2014. The value attribute shall contain the value of the AdaptationSetid attribute from an Adaptation Set with content type audio which the curren
28、t Adaptation Set needs to be mixed with in order to provide complete audio experience. An example of receiver mix, is the case where a single audio Adaptation Set provides music and effects i.e., complete experience without dialogues, and one or more Adaptation Sets provide dialogues in different la
29、nguages. In this case the dialogue Adaptation Sets will depend on music and effects Adaptation Set. The mixing requirement is unidirectional i.e., requirement of mixing Representation A with Representation B when A is selected does not imply that mixing the two is required if B is selected. ISO/IEC
30、23009-1:2014/Amd 2:2015(E) 4 ISO/IEC 2015 All rights reservedAdd the following annexes: ISO/IEC 23009-1:2014/Amd 2:2015(E) ISO/IEC 2015 All rights reserved 5Annex H (normative) Spatial Relationship Description H.1 Spatial Relationship Description (SRD) scheme The SRD scheme allows Media Presentation
31、 Description authors to express spatial relationships between Spatial Objects. A Spatial Object is represented by either an Adaptation Set or a Sub-Representation. As an example, a spatial relationship may express that a video represents a spatial part of another full-frame video (e.g. a region of i
32、nterest, or a tile). The SupplementalProperty and/or EssentialProperty descriptors with schemeIdUri equal to “urn:mpeg:dash:srd:2014“ are used to provide spatial relationship information associated to the containing Spatial Object. SRD shall be contained exclusively in these two MPD elements (Adapta
33、tionSet and SubRepresentation). To preserve the compatibility with legacy clients, MPD shall use SupplementalProperty and EssentialProperty in such a way that at least one Representation can be interpreted by legacy clients after discarding the element containing EssentialProperty. NOTE Sub-Represen
34、tation level SRDs may be used to represent Spatial Objects in one Representation such as HEVC tiling streams. In that case, SRD descriptors may be present at Adaptation Set as well as Sub- Representation levels. H.2 SRD value syntax The value of the SupplementalProperty or EssentialProperty elements
35、 using the SRD scheme is a comma separated list of values for SRD parameters. The source_id parameter provides a unique identifier, within the Period, for the source of the content. It implicitly defines a coordinate system associated to this source. This coordinate system uses an arbitrary origin (
36、0; 0); the x-axis is oriented from left to right and the y-axis from top to bottom. All SRD sharing the same source_id value have the same origin and axes orientations. Spatial relationships for Spatial Objects using SRD with different source_id values are undefined. For a given source_id value, a r
37、eference space is defined, corresponding to the rectangular region encompassing the entire source content, whose top-left corner is at the origin of the coordinate system. The total_width and total_height values in a SRD provide the size of this reference space expressed in arbitrary units. NOTE The
38、re may be no Spatial Object in the MPD that covers the entire source of the content, e.g. when the entire source content is represented by two separate videos. The object_x and object_y parameters (respectively object_width and object_height) express 2D positions (respectively 2D sizes) of the assoc
39、iated Spatial Object in the coordinate system associated to the source. The values of the object_x, object_y, object_width, and object_height parameters are relative to the values of the total_width and total_height parameters, as defined above. Positions (object_x, object_y) and sizes (object_width
40、, object_height) of SRDs sharing the same source_id value may be compared after taking into account the size of the reference space, i.e. after the object_x and object_width values are divided by the total_width value and the object_y and object_height values divided by the total_height value of the
41、ir respective descriptors. ISO/IEC 23009-1:2014/Amd 2:2015(E) 6 ISO/IEC 2015 All rights reservedNOTE Different total_width and total_height values may be used in different descriptors to provide positions and sizes information in different units for the same reference space. MPD authors can express,
42、 using the spatial_set_id parameter, that some Spatial Objects, within a given source_id, have a particular spatial relationship. For instance, an MPD author may group all Adaptation Sets corresponding to tiles at a same resolution level. This way, the spatial_set_id parameter may be used by the DAS
43、H client to quickly select spatially related Spatial Objects. When multiple full-frame videos which consist of one or more Spatial Objects with the same total_width and total_height value, different values of spatial_set_id can be used to distinguish the groups of full-frame video. NOTE ISO/IEC 2300
44、9-3 gives concrete examples showing how to use the spatial_set_id. When value is not present, the SRD does not express any spatial relationship information at all and can be ignored. Table H.1 EssentialPropertyvalue and/or SupplementalPropertyvalue attributes for the SRD scheme EssentialPropert yval
45、ue or SupplementalProp ertyvalue parameter Use Description source_id M non-negative integer in decimal representation providing the identifier for the source of the content object_x M non-negative integer in decimal representation expressing the horizontal position of the top-left corner of the Spat
46、ial Object in arbitrary units object_y M non-negative integer in decimal representation expressing the vertical position of the top- left corner of the Spatial Object in arbitrary units object_width M non-negative integer in decimal representation expressing the width of the Spatial Object in arbitr
47、ary units object_height M non-negative integer in decimal representation expressing the height of the Spatial Object in arbitrary units total_width O optional non-negative integer in decimal representation expressing the width of the reference space in arbitrary units. At each Period and for a given
48、 source_id value, the following rules apply: - There shall be at least one descriptor providing a value for the total_width parameter. - If two or more descriptors provide different total_width values, all other descriptors shall explicitly provide the value of total_width. - If the total_width valu
49、e is provided in only one descriptor, all other descriptors are assumed to use that total_width value. - The value of total_width shall be such that, for each descriptor using this value of total_width, the sum of object_x and object_width is smaller or equal to total_width. When the value total_width is present, the value total_height shall be present. total_height O optional non-negative integer in decimal representation expressing the height of
