1、Information technology Coding of audio-visual objects Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) AMENDMENT 2: Technology for scene adaptationAmendment 2:2010 (IDT) toNational Standard of CanadaCAN/CSA-ISO/IEC 14496-20-09(ISO/IEC 14496-20:2008, I
2、DT)NOT FOR RESALE.PUBLICATION NON DESTINE LA REVENTE.CSA Standards Update ServiceAmendment 2:2010 toCAN/CSA-ISO/IEC 14496-20-09December 2010Title: Information technology Coding of audio-visual objects Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) A
3、MENDMENT 2: Technology for scene adaptationPagination:16 pages (iii preliminary and 13 text)To register for e-mail notification about any updates to this publicationgo to www.shopcsa.caclick on E-mail Services under MY ACCOUNTclick on CSA Standards Update ServiceThe List ID that you will need to reg
4、ister for updates to this publication is 2419923.If you require assistance, please e-mail techsupportcsa.ca or call 416-747-2233.Visit CSAs policy on privacy at www.csagroup.org/legal to find out how we protect your personal information.Reference numberISO/IEC 14496-20:2008/Amd.2:2010(E)ISO/IEC 2010
5、INTERNATIONAL STANDARD ISO/IEC14496-20Second edition2008-12-01AMENDMENT 22010-03-01Information technology Coding of audio-visual objects Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) AMENDMENT 2: Technology for scene adaptation Technologies de linf
6、ormation Codage des objets audiovisuels Partie 20: Reprsentation de scne dapplication allge (LASeR) et format dagrgation simple (SAF) AMENDEMENT 2: Technologies pour adaptation de scne ISO/IEC 14496-20:2008/Amd.2:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with
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11、se postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org ii ISO/IEC 2010 All rights reservedAmendment 2:2010 to CAN/CSA-ISO/IEC 14496-20-09ISO/IEC 14496-20:2008/Amd.2:2010(E) ISO/IEC 2010 All rights reserved iiiForeword ISO (the Internation
12、al 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
13、 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
14、 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 technical committee is to prepare International Standards. Draft Inte
15、rnational 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 drawn to the possibility that some of the elements of this docume
16、nt 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 14496-20:2008 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multime
17、dia and hypermedia information. Amendment 2:2010 to CAN/CSA-ISO/IEC 14496-20-09ISO/IEC 14496-20:2008/Amd.2:2010(E) ISO/IEC 2010 All rights reserved 1Information technology Coding of audio-visual objects Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)
18、 AMENDMENT 2: Technology for scene adaptation In Table 3, add the following new LASeR events: Event name Namespace Description Bubble Canc. IDL “DisplaySizeChanged(A)” Urn:mpeg:mpeg4:laser:200x Occurs when the terminal screen or viewport size has been changed to the specified A value. A is expressed
19、 in Inches. DisplaySizeChangedEvent “MemoryStatus(a,b,c)” Urn:mpeg:mpeg4:laser:200x Occurs when the terminal memory occupancy changes more than the each specified parameter. MemoryStatusEvent The parameters of MemoryStatus event are: a: number of graphics points. If the number of graphic points rele
20、ased/allocated by the terminal is strictly less than a, the event is not triggered. b: number of Unicode characters. If the number of Unicode characters released/allocated by the terminal is strictly less than b, the event is not triggered. c: size, in kilo-bytes, of the composition buffers (as desc
21、ribed in 6.11.3). If the size released/allocated by the terminal is strictly less than c, the event is not triggered. In 6.5.6, add the new attribute delta to ExternalValueEvent: interface ExternalValueEvent : LASeREvent readonly attribute float absoluteValue; readonly attribute boolean computableAs
22、Fraction; readonly attribute float fraction; readonly attribute signed long delta; ; Attributes absoluteValue: This value represent the status of a resource of any kind, e.g. the remaining battery time. computableAsFraction: This value indicates whether a fraction can be computed from the absoluteVa
23、lue. fraction: This value shall be between 0 and 1 inclusively and represent the status of the resource, e.g. the fraction of remaining battery time over operation time when fully charged. delta: The delta field carries the difference of absoluteValue between this occurrence of the event and the pre
24、vious occurrence. Amendment 2:2010 to CAN/CSA-ISO/IEC 14496-20-09ISO/IEC 14496-20:2008/Amd.2:2010(E) 2 ISO/IEC 2010 All rights reservedAfter 6.5.6.2, add the following new subclauses: 6.5.6.3 DisplaySizeChanged Event interface DisplaySizeChangedEvent : LASeR Event readonly attribute SVGLength diagon
25、al; readonly attribute SVGLength screenWidth; readonly attribute SVGLength screenHeight; ; No defined constants Attributes diagonal: This value indicates the new screen or viewport diagonal size. The diagonal value must be consistent with the screenWidth and screenHeight values. The value is express
26、ed in inches. screenWidth: This value indicates the new viewport width. The value is expressed in pixels. screenHeight: This value indicates the new viewport height. The value is expressed in pixels. 6.5.6.4 MemoryStatus Event interface MemoryStatusEvent : LASeR Event readonly attribute integer numb
27、erOfPoints; readonly attribute Integer numberOfCharacters; readonly attribute Integer compositionMemoySize; ; No defined constants Attributes numberOfPoints: number of points allocated/freed by the terminal. numberOfCharacters: number of Unicode characters allocated/freed by the terminal. compositio
28、nMemoySize: composition memory size of images allocated/freed by the terminal. In 6.6.2.2, add the following new attributes and tables: adaptationType: the LASeRHeader can signal a set of adaptation constraints in the form of type and value pairs. These type and value pairs can then be referenced in
29、 an AdpativeUpdateGroup update to indicate that the given group of updates shall only be applied if the given adaptation constraints match the LASeR engine characteristics (e.g. required display size). The list of adaptation types is given in Table AMD2.1. adaptationTypeValue: indicates the value of
30、 the required LASeR engine characteristic described in the adaptation constraint type. adaptationConstraints: this attribute represents a list of indexes in the set of adaptation constraints required to process the scene segment. Amendment 2:2010 to CAN/CSA-ISO/IEC 14496-20-09ISO/IEC 14496-20:2008/A
31、md.2:2010(E) ISO/IEC 2010 All rights reserved 3Table AMD2.1 adaptationType values adaptationType Description 0x01 Indicates the minimum viewport size required to process the associate LASeR update. The value describes the viewport diagonal, expressed in inches. 0x02 minimum memory size expressed in
32、the same unit as min memory attribute. 0x03 adaptation filter as defined in 6.13 0x04 implicit Boolean (eg no value coded) evaluating to TRUE if the terminal is capable of mixing an additional audio object 0x05 Boolean evaluating to TRUE if the terminal is capable of composing an additional image ob
33、ject. One parameter is given to determine whether overlaying or regular composition is desired 0x06 Boolean evaluating to TRUE if the terminal is capable of composing an additional video object. One parameter (Boolean, one bit) is given to determine whether overlaying or regular composition is desir
34、ed 0x07 Evaluates to TRUE if the indicated Interaction method is supported. Refer to Table AMD2.2 for a list interaction method types 0x08 0xFF Reserved Table AMD2.2 InteractionMethodType values InteractionMethodType Description 0x00 None. 0x01 Stylus 0x02 Mouse 0x03 Full keyboard 0x04 Keypad (cellp
35、hone or similar) 0x05-0x80 ISO Reserved 0x81-xFE User Reserved 0xFF ISO Reserved After 6.7.16, add the following new subclause: 6.7.17 AdaptiveUpdateGroup 6.7.17.1 Semantics The AdaptiveUpdateGroup update is a wrapper of LASeR updates with an indication of the associated required adaptation criteria
36、. It can be used for adaptation purposes. 6.7.17.2 Attributes adaptationConstraints: this attribute represents a list of indexes in the set of adaptation constraints defined in the LASeRHeader required to process the associated group of updates. Amendment 2:2010 to CAN/CSA-ISO/IEC 14496-20-09ISO/IEC
37、 14496-20:2008/Amd.2:2010(E) 4 ISO/IEC 2010 All rights reservedFigure AMD2.1 LASeR updates in one LASeR Access Unit (AU). Example of Scene Segment Level and Command Level Switching: commands(e.g., Add, Delete, ) commands commands commands Amendment 2:2010 to CAN/CSA-ISO/IEC 14496-20-09ISO/IEC 14496-
38、20:2008/Amd.2:2010(E) ISO/IEC 2010 All rights reserved 5At the end of 6.8.3, add the following new paragraph: The xlink:href attribute of the a element may contain a special URL such as “tel:06778899”, thus using the rfc3966 definition in order to signal a “click to call” element. Other special URLs
39、 may be used to send messages to external systems for which the LASeR engine works as user interface. After 6.8.59, add the following new subclause: 6.8.60 LASeR parsingSwitch 6.8.60.1 Semantics The parsingSwitch element is a parsing construct which signals scene tree alternatives with respect to me
40、mory requirements. A LASeR engine loads parsingSwitch subtrees in the scene tree based on its memory occupancy. The minMemory attribute may be used on direct children elements of the parsingSwitch to indicate the foreseen memory requirements. The children of the parsingSwitch element are loaded acco
41、rding to the mode attribute. 6.8.60.2 attributes mode: this attribute selects how children of the parsingSwitch element are loaded by the LASeR engine. It can take the following values o ”descending”: the children of the parsingSwitch element are listed in decreasing order with respect to their memo
42、ry requirements and only the first subtree that fits in the available memory is loaded. o “ascending”: the children of the parsingSwitch element are listed in increasing order with respect to their memory requirements and only the last subtree that fits in the available memory is loaded. o “incremen
43、tal”: the children of the parsingSwitch element are listed in increasing order with respect to their memory requirements. Subtrees are loaded in listed order and loading stops at the first subtree that doesnt fit in the available memory. Amendment 2:2010 to CAN/CSA-ISO/IEC 14496-20-09ISO/IEC 14496-2
44、0:2008/Amd.2:2010(E) 6 ISO/IEC 2010 All rights reservedFigure AMD2.2 illustrates the different modes of the parsingSwitch element. Numbers indicate the subtree order in the element and box sizes represent the memory footprint of each subtree. (a) mode=“descending“ (b) mode=“ascending“ 123(c) mode=“i
45、ncremental“ Figure AMD2.2 illustration of parsingSwitch mode attribute After 6.10, add the following new subclauses: 6.11 Attributes for static adaptation Attributes for static adaptation are similar to “conditional processing attributes” of SVG, except that they are evaluated only when the element
46、is loaded or whenever deemed necessary by the LASeR Engine implementation. Elements for which static adaptation attributes are evaluated to false, are still part of the DOM. An evaluation result of false is equivalent to setting the display presentation attribute to none. The static adaptation attri
47、butes cannot be animated or updated. 6.11.1 Container element attributes extension The static adaptation attributes defined in this Subclause are added to the following elements: a, g, svg, switch, lsr:conditional, lsr:rectclip, lsr:selector, lsr:simplelayout. Amendment 2:2010 to CAN/CSA-ISO/IEC 144
48、96-20-09ISO/IEC 14496-20:2008/Amd.2:2010(E) ISO/IEC 2010 All rights reserved 76.11.2 Display Size adaptation The minDisplaySize attribute specifies the minimum display size required to display the element to which it applies. The display size refers to the size of the viewport (e.g., document window
49、 .). The dimension of the display size is expressed in inches and represents the length of the viewport diagonal. 6.11.3 Memory adaptation The minMemory attribute specifies a set of parameters which may be used by the LASeR engine to determine if it has enough available memory to display the subtree. The parameters are: The total number of points in the subtree. The number of Unicode characters in the subtree. The size, in ki
