ISO/IEC FDIS 23009-2

FINAL
INTERNATIONAL ISO/IEC
DRAFT
STANDARD FDIS
23009-2
ISO/IEC JTC 1/SC 29
Information technology — Dynamic
Secretariat: JISC
adaptive streaming over HTTP
Voting begins on:
2020-06-11 (DASH) —
Voting terminates on:
Part 2:
2020-08-06
Conformance and reference software
Technologies de l'information — Diffusion en flux adaptatif
dynamique sur HTTP (DASH) —
Partie 2: Conformité et logiciel de référence
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/IEC FDIS 23009-2:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. ISO/IEC 2020
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ISO/IEC FDIS 23009-2:2020(E)
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© ISO/IEC 2020

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on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms, definitions, symbols and abbreviated terms ....................................................................................................... 1

4 Media presentation conformance....................................................................................................................................................... 1

4.1 Overview ...................................................................................................................................................................................................... 1

4.2 Software tools .......................................................................................................................................................................................... 2

5 MPD conformance ............................................................................................................................................................................................... 2

5.1 General ........................................................................................................................................................................................................... 2

5.2 Static MPD conformance ................................................................................................................................................................ 3

5.3 Dynamic MPD conformance ........................................................................................................................................................ 4

5.3.1 General...................................................................................................................................................................................... 4

5.3.2 Background and requirements ............................................................................................................................ 4

5.3.3 Dynamic conformance software design ....................................................................................................... 6

5.4 Conformance checks for spatial relationship description ................................................................................. 7

6 Segment conformance .................................................................................................................................................................................... 8

6.1 Overview ...................................................................................................................................................................................................... 8

6.2 Representation conformance ..................................................................................................................................................... 9

6.2.1 ISO base media file format....................................................................................................................................... 9

6.2.2 MPEG-2 transport stream .....................................................................................................................................10

6.3 Adaptation set conformance ....................................................................................................................................................13

6.3.1 ISO base media file format....................................................................................................................................13

6.3.2 MPEG-2 transport stream .....................................................................................................................................14

6.4 Dynamic media presentation conformance ................................................................................................................16

7 Profile specific conformance ................................................................................................................................................................16

7.1 ISO base media file format on demand profile .........................................................................................................16

7.2 ISO base media file format live profile .............................................................................................................................16

7.3 ISO base media file format main profile .........................................................................................................................16

7.4 MPEG-2 transport stream simple profile ......................................................................................................................17

8 Conforming test vectors .............................................................................................................................................................................17

9 DASH access engine reference software ....................................................................................................................................17

9.1 General ........................................................................................................................................................................................................17

9.2 libdash overview ................................................................................................................................................................................17

9.3 libdash-enabled example system ........................................................................................................................................18

9.4 libdash availability ............................................................................................................................................................................19

10 Conformance software for ISO/IEC 23009-4 ........................................................................................................................19

10.1 General ........................................................................................................................................................................................................19

10.2 Design limitations and assumptions .................................................................................................................................19

10.3 Usage.............................................................................................................................................................................................................19

11 Conformance for ISO/IEC 23009-5 server and network-assisted DASH (SAND) .............................20

11.1 Conformance rules ............................................................................................................................................................................20

11.2 Software .....................................................................................................................................................................................................23

11.2.1 Design and architecture ..........................................................................................................................................23

11.2.2 Usage .......................................................................................................................................................................................24

11.3 Test vectors .............................................................................................................................................................................................28

12 Conformance for ISO/IEC 23009-6 server push ................................................................................................................28

12.1 Architecture ............................................................................................................................................................................................28

12.2 Status ............................................................................................................................................................................................................29

12.3 Logistics .....................................................................................................................................................................................................30

12.4 Usage.............................................................................................................................................................................................................31

Annex A (normative) MPD conformance checking .............................................................................................................................32

Annex B (normative) Test vectors ........................................................................................................................................................................74

Annex C (informative) Sample software ........................................................................................................................................................79

Annex D (informative) Dynamic media presentation emulator ...........................................................................................82

Annex E (informative) Coverage of DASH features ..............................................................................................................................83

Bibliography .............................................................................................................................................................................................................................87

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

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

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

This document was prepared by Joint Techncial Committee ISO/IEC JTC 1, Information technology, SC 29,

This third edition cancels and replaces the second edition (ISO/IEC 23009-2:2017), which has been

a) Test vectors, conformance and reference software to cover all the features of ISO/IEC 23009-5,

b) Test vecors, conformance and reference software to cover all the features of ISO/IEC 23009-6,

The conformance and reference software of the ISO/IEC 23009 series serves three main purposes:

— validation of the written specification of the Parts of the ISO/IEC 23009 series;

— clarification of the written specification of the Parts of the ISO/IEC 23009 series;

— conformance testing for checking interoperability for the various applications against the reference

This document specifies the conformance and reference software implementing the test vectors

comprising media presentation descriptions, segments and combinations thereof in ISO/IEC 23009-1,

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 19757-3, Information technology — Document Schema Definition Languages (DSDL) — Part 3:

ISO/IEC 23009-1:2019, Information technology — Dynamic adaptive streaming over HTTP (DASH) —

ISO 8601-1, Date and time — Representations for information interchange — Part 1: Basic rules

ISO/IEC 23009-5:2017, Information technology — Dynamic adaptive streaming over HTTP (DASH) —

For the purpose of this document, the terms, definitions, symbols and abbreviated terms given in

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

A media presentation conforming to ISO/IEC 23009-1 obeys the rules for the media presentation

description (MPD) and the segments referenced within the MPD. To verify the conformance of a media

— the conformance of the segments, which includes the conformance of individual segments and

representations, as well as the conformance of representations that are jointly provided in

MPD + segment validator: gets as an input the MPD and segments referenced from within the MPD

and performs the MPD and segment validation according to the rules defined in Annex A. On success,

All software tools are available at https:// standards .iso .org/ iso -iec/ 23009/ -2/ ed -3/ en.

Additional supplemental software packages which may be used as sample DASH clients, sample

This clause specifies the MPD conformance checking and corresponding software modules which

comprise the three steps depicted in Figure 2. Detailed means to perform MPD conformance checking

Step 1 (XLink resolver): gets as an input an MPD document and resolves all W3C XLINK attributes

as defined in ISO/IEC 23009-1. If an error occurs, the corresponding error message shall be provided;

otherwise, the XLink resolved MPD document is provided. The details for this step of the MPD

Step 2 (XML validator): gets as an input an XLink-resolved MPD document and performs XML

validation (i.e. well-formed and valid) against the MPD schema defined in W3C XML and W3C XML

SCHEMA . If an error occurs, the corresponding error message shall be provided; otherwise, the

XLink-resolved and schema-validated MPD document is provided. The details for this step of the MPD

Step 3 (schematron validator): gets as an input an XLink-resolved and schema-validated MPD

document and performs schematron validation as defined in ISO/IEC 19757-3 according to the rules

defined in A.4.2. If an error occurs, the corresponding error message shall be provided; otherwise, the

XLink-resolved, schema-validated, and Schematron-validated MPD document is provided. The details

The following command may be used to validate an MPD document with the chain depicted in Figure 2.

The program outputs a message for each step. If an error occurs during one step, the following steps are

All conformance tools are available at https:// standards .iso .org/ iso -iec/ 23009/ -2/ ed -3/ en.

In addition, the availability of all resources in the MPD during the MPD@availabilityStartTime and the

MPD@availabilityEndTime shall be checked. A function remoteFileExists($url) may be executed for

each segment that is documented in the MPD. This function shall return true for all Segments in the MPD

during the time interval defined by the MPD@availabilityStartTime and the MPD@availabilityEndTime.

The following snippet shows an example for the remoteFileExists function written in PHP.

1) Apache Ant is the trade name of a product supplied by The Apache Software Foundation. This information is

given for the convenience of users of this document and does not constitute an endorsement by ISO or IEC of the

To ensure that servers offering a dynamic DASH media presentation adhere to the timing requirements

and that clients are able to properly consume the dynamic presentation without observing unavailable

segments, the DASH conformance software is extended to include and address media presentations

with MPD@type=ʹdynamicʹ. In 5.3, the requirements which go beyond those for static DASH conformance

are listed and a functional description of the conformance software implementation is provided.

The document is aligned with the guidelines for live services as documented in ISO/IEC TR 23009-3 .

Clients make use of the information in an MPD. Based on an MPD that is fetched at a certain fetch time

1) the latest available period on the server, denoted by its Period start time PS*;

2) the segment availability start time of any segment at position k within the Period, denoted as

3) the position of the latest segment that is available on server in the Period, referred to as k*;

5) the time when to fetch a new MPD based on the current presentation time, or more specifically,

the greatest segment position k' within this Period that can be constructed by this MPD;

6) the media presentation time within the Representation that synchronizes closest to the live

7) the media presentation time within the Representation that synchronizes to other clients, MPTS.

b) At any time, WT, all segments with availability start time at or before WT and availability end time

c) An updated MPD is made available on time, taking into account the minimum update period (MUP)

of the MPD. Note that by not updating the MPD, the existing MPD is validated for another MUP time.

Detailed equations to derive segment availability times are provided in ISO/IEC 23009-1 and

ISO/IEC TR 23009-3 . When providing an MPD, the content author ensures that the segment availability

In order to use the same concepts with different timing and addressing schemes, the following values

Assuming that the wall-clock time at the client is denoted as WT, the client can derive the following

— The latest Period is the Period for which AST + PS + MD(1) ≤ WT where AST is the value of the MPD@

— Within this Period, the latest segment available on the server is the segment at the position k* which

results in the greatest value for SAST(k*) and at the same time is smaller than WT.

— The address of the latest segment can be derived using the position information k*. The exact value

— Within this Period, the greatest segment position k' that can be constructed by this MPD is the one

that results in the greatest value for SAST(k') and at the same time is smaller than FT + MUP.

The media presentation time in a Period is determined for each Representation as the presentation

time value of the media segments minus the value of the @presentationTimeOffset, if present, for each

It is further assumed that a segment at position k has an assigned earliest media presentation time EPT(k).

— Each segment at position k in this Period is available prior to the sum of its earliest presentation

— If each segment with segment number k is delivered starting at SAST(k) over a constant bitrate channel

with bitrate equal to the value of the @bandwidth attribute, then each sample with presentation time

PT shall be available at the client by the time given by PT + (AST + PS) + MBT + MD(k).

— Each segment in this Period shall be available at least until SAST(k) + TSB + MD(k).

— The MPD can be used to construct and request segments until media time FT + MUP. The greatest

segment position k' that can be constructed by this MPD shall be the one that results in the greatest

value for SAST(k') and at the same time is smaller than FT + MUP. Note that the latest segment may

In addition, updates of the MPD shall be consistent according to ISO/IEC 23009-1:2019, 5.4.

The implementation of the conformance software for dynamic services requires the implementation of

Two different cases are considered depending on the access bandwidth to the server.

In case 1, it is assumed that the conformance checker is operating with a very high (infinite) access

1) The smallest segment availability start time greater than FT of any Segment in any

2) The URLs of all segments available at SAST . If multiple segments are available at the same

c) For all segments with segment availability, end time greater than FT and smaller than SAST ,

d) At time SAST issue HTTP GET requests for all segments that become available at this time,