1、 Reference number ISO/IEC 23009-1:2014(E) ISO/IEC 2014INTERNATIONAL STANDARD ISO/IEC 23009-1 Second edition 2014-05-15 Information technology Dynamic adaptive streaming over HTTP (DASH) Part 1: Media presentation description and segment formats Technologies de linformation Diffusion en flux adaptati
2、f dynamique sur HTTP (DASH) Partie 1: Description de la prsentation et formats de remise des mdias ISO/IEC 23009-1:2014(E) COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by
3、any means, electronic or mechanical, 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 Case postale 56 CH-1211
4、 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2014 All rights reservedISO/IEC 23009-1:2014(E) ISO/IEC 2014 All rights reserved iiiContents Page Foreword . v Introduction vi 1 Scope 1 2 Normative references 1 3 Term
5、s, definitions, symbols and abbreviated terms . 2 3.1 Terms and definitions . 2 3.2 Symbols and abbreviated terms 5 3.3 Conventions . 6 4 Introduction 7 4.1 System description . 7 4.2 DASH client model 8 4.3 DASH data model overview 9 4.4 Protocols 11 4.5 Media Stream and Representation properties 1
6、2 4.6 Brands 14 4.7 Schemes . 15 5 Media Presentation 16 5.1 General . 16 5.2 Media Presentation Description . 16 5.3 Hierarchical data model 18 5.4 Media Presentation Description updates 61 5.5 MPD assembly . 62 5.6 Base URL Processing . 64 5.7 Program information . 66 5.8 Descriptors . 67 5.9 DASH
7、 metrics descriptor 74 5.10 Events . 75 6 Segment formats . 82 6.1 Introduction 82 6.2 Segment types . 83 6.3 Segment formats for ISO base media file format . 85 6.4 Segment formats for MPEG-2 transport streams . 88 7 Combined semantics of MPD and Segment formats . 94 7.1 Introduction 94 7.2 General
8、 . 95 7.3 Media Presentation based on the ISO base media file format 96 7.4 Media Presentation based on MPEG-2 TS 98 8 Profiles 100 8.1 Definition 100 8.2 Full profile 101 8.3 ISO Base media file format On Demand profile . 101 8.4 ISO Base media file format live profile 103 8.5 ISO Base media file f
9、ormat main profile . 104 8.6 MPEG-2 TS main profile 105 8.7 MPEG-2 TS simple profile . 106 Annex A (informative) Example DASH client behaviour . 108 A.1 Introduction 108 ISO/IEC 23009-1:2014(E) iv ISO/IEC 2014 All rights reservedA.2 Overview 108 A.3 Segment list generation . 109 A.4 Seeking 112 A.5
10、Support for trick modes . 113 A.6 Switching Representations 113 A.7 Reaction to error codes . 113 A.8 Encoder clock drift control 114 Annex B (normative) MPD schema . 115 Annex C (normative) MIME type registration for MPD . 121 C.1 Introduction . 121 C.2 MIME type and subtype 121 C.3 Parameters 122
11、C.4 MPD Anchors 122 Annex D (normative) DASH Metrics . 124 D.1 Introduction . 124 D.2 DASH-Metrics client reference model. 124 D.3 Definition of observation points 124 D.4 Semantics of the DASH metrics 125 Annex E (normative) Byte range requests with regular HTTP GET methods 131 E.1 Background . 131
12、 E.2 Construction rule 131 E.3 Examples . 132 Annex F (informative) Guidelines for extending DASH with other delivery formats . 133 F.1 Adding delivery formats to DASH . 133 F.2 Media Presentation authoring rules 133 Annex G (informative) MPD Examples and MPD Usage . 134 G.1 Example MPD for ISO Base
13、 media file format On Demand profile 134 G.2 Example for ISO Base media file format Live profile 135 G.3 Example for MPEG-2 TS Simple profile 136 G.4 Example for multiple stereo views 137 G.5 Example for SVC alternative streams . 138 G.6 Example for trick play support 139 G.7 Example for content pro
14、tected by multiple schemes . 140 G.8 Example for usage of Role descriptor 141 G.9 Example for usage of Event Messaging . 142 Bibliography . 144 ISO/IEC 23009-1:2014(E) ISO/IEC 2014 All rights reserved vForeword ISO (the International Organization for Standardization) and IEC (the International Elect
15、rotechnical 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 techni
16、cal 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 technic
17、al 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 technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circ
18、ulated 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 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
19、 responsible for identifying any or all such patent rights. ISO/IEC 23009-1 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information. This second edition cancels and replaces the first edition
20、 (ISO/IEC 23009-1:2012), which has been technically revised. It also incorporates the Technical Corrigendum ISO/IEC 23009-1:2012/Cor.1:2013. ISO/IEC 23009 consists of the following parts, under the general title Information technology Dynamic adaptive streaming over HTTP (DASH): Part 1: Media presen
21、tation description and segment formats Part 2: Conformance and reference software Part 3: Implementation guidelines Technical Report Part 4: Segment encryption and authentication ISO/IEC 23009-1:2014(E) vi ISO/IEC 2014 All rights reservedIntroduction Dynamic Adaptive Streaming over HTTP (DASH) is in
22、tended to support a media-streaming model for delivery of media content in which control lies exclusively with the client. Clients may request data using the HTTP protocol from standard web servers that have no DASH-specific capabilities. Consequently, this part of ISO/IEC 23009 focuses not on clien
23、t or server procedures but on the data formats used to provide a DASH Media Presentation. This part of ISO/IEC 23009 primarily specifies formats for the Media Presentation Description and Segments. It is applicable to streaming services over the Internet. INTERNATIONAL STANDARD ISO/IEC 23009-1:2014(
24、E) ISO/IEC 2014 All rights reserved 1Information technology Dynamic adaptive streaming over HTTP (DASH) Part 1: Media presentation description and segment formats 1 Scope This part of ISO/IEC 23009 primarily specifies formats for the Media Presentation Description and Segments for dynamic adaptive s
25、treaming delivery of MPEG media over HTTP. It is applicable to streaming services over the Internet. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cite
26、d applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ITU-T Rec. H.222.0 | ISO/IEC 13818-1, Information technology Generic coding of moving pictures and associated audio information: Systems ISO/IEC 14496-10, Information technology Codin
27、g 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 (technically identical to ISO/IEC 15444-12) ISO/IEC 23001-8, Information technology MPEG systems technologies Part 8: Coding-independen
28、t code points IETF RFC 2141, URN Syntax, May 1997 IETF RFC 2616, Hypertext Transfer Protocol HTTP/1.1, June 1999 IETF RFC 3023, XML Media Types, January 2001 IETF RFC 3406, Uniform Resource Names (URN) Namespace Definition Mechanisms, October 2002 IETF RFC 3629, UTF-8, a transformation format of ISO
29、 10646, November 2003 IETF RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, January 2005 IETF RFC 4122, A Universally Unique IDentifier (UUID) URN Namespace, July 2005 IETF RFC 4288, Media Type Specifications and Registration Procedures, December 2005 IETF RFC 4337, MIME Type Registratio
30、n for MPEG-4, March 2006 ISO/IEC 23009-1:2014(E) 2 ISO/IEC 2014 All rights reservedIETF RFC 4648, The Base16, Base32, and Base64 Data Encodings, October 2006 IETF RFC 5261, An Extensible Markup Language (XML) Patch Operations Framework Utilizing XML Path Language (XPath) Selectors, September 2008 IE
31、TF RFC 5646, Tags for Identifying Languages, September 2009 IETF RFC 6265, HTTP State Management Mechanism, April 2011 IETF RFC 6381, The Codecs and Profiles Parameters for “Bucket“ Media Types, August 2011 W3C XLINK XML Linking Language (XLink) Version 1.1, W3C Recommendation 06, May 2010 W3C Media
32、 Fragments URI 1.0 (basic), W3C Recommendation, 25 September 2012 3 Terms, definitions, symbols and abbreviated terms 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 access unit unit of a media stream with an assigned Media Presentation t
33、ime 3.1.2 accessibility degree to which a media content or certain media content components are available to as many people as possible 3.1.3 Adaptation Set set of interchangeable encoded versions of one or several media content components 3.1.4 asset content including media and metadata together wi
34、th the rights to use the content by the content provider 3.1.5 available Segment Segment that is accessible at its assigned HTTP-URL and a possibly assigned byte range that is the request with an HTTP GET results in a reply of the Segment and 2xx status code 3.1.6 Bitstream Switching Segment Segment
35、 that if present contains essential data to switch to the Representation it is assigned to 3.1.7 complementary Representation Representation which complements at least one dependent Representation 3.1.8 continuous media media with an inherent notion of time, for example, speech, audio, video, timed
36、text or timed metadata ISO/IEC 23009-1:2014(E) ISO/IEC 2014 All rights reserved 33.1.9 DASH metric metric identified by a key and defined in this part of ISO/IEC 23009 3.1.10 dependent Representation Representation for which Segments from its complementary Representations are necessary for presentat
37、ion and/or decoding of the contained media content components 3.1.11 earliest presentation time smallest presentation time of any access unit of a Media Segment or Subsegment for a media stream 3.1.12 event aperiodic sparse media-time related auxiliary information to the DASH client or to an applica
38、tion 3.1.13 event stream sequence of related events 3.1.14 group collection of Adaptation Sets that are not expected to be presented simultaneously 3.1.15 HTTP-URL URL with a fixed scheme of “http” or “https” 3.1.16 Index Segment Segment that primarily contains indexing information for Media Segment
39、s 3.1.17 Initialization Segment Segment containing metadata that is necessary to present the media streams encapsulated in Media Segments 3.1.18 media content one media content period or a contiguous sequence of media content periods 3.1.19 media content component one continuous component of the med
40、ia content with an assigned media component type that can be encoded individually into a media stream 3.1.20 media content component type single type of media content such as audio, video, or text 3.1.21 media content period set of media content components that have a common timeline as well as rela
41、tionships on how they can be presented 3.1.22 Media Presentation collection of data that establishes a bounded or unbounded presentation of media content ISO/IEC 23009-1:2014(E) 4 ISO/IEC 2014 All rights reserved3.1.23 Media Presentation Description MPD formalized description for a Media Presentatio
42、n for the purpose of providing a streaming service 3.1.24 Media Presentation timeline concatenation of the timeline of all Periods which itself is common to all Representations in the Period 3.1.25 Media Segment Segment that complies with media format in use and enables playback when combined with z
43、ero or more preceding segments, and an Initialization Segment (if any) 3.1.26 media stream encoded version of a media content component 3.1.27 Media Subsegment Subsegment that only contains media data but no Segment Index 3.1.28 message part of an event containing information that is exclusively han
44、dled by the event handler 3.1.29 MPD start time approximate presentation start time of a Media Segment signalled in MPD 3.1.30 MPD duration approximate presentation duration of a Media Segment signalled in MPD 3.1.31 Period interval of the Media Presentation, where a contiguous sequence of all Perio
45、ds constitutes the Media Presentation 3.1.32 presentation time time associated to an access unit that maps it to the Media Presentation timeline 3.1.33 remote element entity entity that contains one or more elements and is referenced in the MPD with an HTTP-URL contained in an xlink:href attribute 3
46、.1.34 Representation collection and encapsulation of one or more media streams in a delivery format and associated with descriptive metadata 3.1.35 Segment unit of data associated with an HTTP-URL and optionally a byte range that are specified by an MPD ISO/IEC 23009-1:2014(E) ISO/IEC 2014 All right
47、s reserved 53.1.36 Segment availability start time latest time instant in wall-clock time at which a Segment becomes an available Segment 3.1.37 adjusted Segment availability start time time instant in wall-clock time at which a Segment becomes an available Segment 3.1.38 Segment availability end ti
48、me time instant in wall-clock time at which a Segment ceases to be an available Segment 3.1.39 Segment Index compact index of the time range to byte range mapping within a Media Segment separately from the MPD 3.1.40 stream access point SAP position in a Representation enabling playback of a media s
49、tream to be started using only the information contained in Representation data starting from that position onwards (preceded by initializing data in the Initialization Segment, if any) 3.1.41 Sub-Representation part of a Representation described in the MPD that is present in the entire Period 3.1.42 Subsegment unit within Media Segments that is indexed by a Segment Index 3.1.43 valid Segment URL HTTP-URL that is promised to reference a Segment during its Segment availability period 3.1.44 wall-clo
