CARDIFF UNIVERSITY EXAMINATION PAPER Academic Year: 1999/2000 Examination Period Autumn Examination Paper Number CM0340 Examination Paper Title: Multimedia Duration Do not turn this page over until instructed to do so by the senior invigilator Structure of Examination Paper: There are Three pages and Four questions Students to be provided with: Answer Book(s) Multimedia information sheets Instructions to Students Attempt ThreE questions Each question is worth 27 marks Please Turn Over
1.(a)What is meant by the terms Multimedia and Hypermedia? Distinguish between these two concepts b)What is meant by the terms static media and dynamic media? Give two examples of each type of med (c) What types of functionality need to be provided in order to effectively use a wide variety of media in Multimedia applications? Your answer should briefly address how such functionality can be facilitated in general Multimedia applications (d) Different types of media will require different types of supporting operations to provide adequate levels of fur nationality. For th dynamic media given in your answer to part 1(b) briefly discuss what operations are needed to support a wide range of multimedia applications [12 2.(a)Why is file or data compression highly desirable for Multimedia activities? b)briefly explain, clearly identifying the differences between them, how entropy coding and transform coding techniques work for data compression Illustrate your answer with a simple example of each type (c)(i)Show how you would use Huffman coding to encode the following set of tokens BABACACADADABBCBABEBEDDABEEEBB How is this message transmitted when encoded? (11) How many bits are needed to transfer this coded message and what is its Entropy? (iii)What amendments are required to this coding technique if data is generated live or is otherwise not wholly available? Show how you could use this modified scheme by adding the tokens ADADA to the above message. [6]
3 (a)What are the major factors to be taken into account when considering storage requirements for Multimedia Systems (b)What is RAID technology and what advantages does it offer as a medium for the storage and delivery of large data (c) Briefly explain the eight levels of RAID functionality (d)a digital video file is 40 Mb in size. The disk subsystem has four drives and the controller is designed to support read and write onto each drive, concurrently. The digital video is stored using the disk striping concept. A block size of 8 Kb is used for each 1O operation (i)What is the performance improvement in sequentially complete file when compared to a single drive subsystem in terms of the number of operations performed compared to a single drive system mance improvement for this system (ii)What is the percentage perfo 4(a) Give a definition of a Multimedia Authoring System. What key features hould such a system provide? (b)What Multimedia Authoring paradigms exist? Describe each paradigm brief (c) You have been asked to provide a multimedia presentation that can support media in both English and French. You may assume that you have been given a equence of 10 images and a single 50 second digitised audio soundtrack in both languages. Each image should be mapped over consecutive 5 second fragments of the audio. all images are of the same 500x 500 pixel dimension Describe, giving suitable code fragments, how you would assemble such a ation using SMIL. Your solution should cover all aspects of the SMiL presentation. 17]
faedis, Derbe 7, tiss Seronine Mdia itly in Language atribute value. The syntax of such atmbute values is defined using the Extended Backus. Naur Form(EBNF) Multimedia CM0340 Suplementary Exam Material dfi in t M .i picton. Synchronized M山 Itimedia Integration Language如出时k邮 (SMIL) 1.0 Specification e semantics of the attribu e are defined. Ift ation refers to the definition of the atlnbute in t definition of element Abstract noation. The final section in an element definition sm alues whose syntan cannot be defined using the DTD pecifies the element cor SMIL LO, pronounced 2 The smil Element presentation. UsI an author ca Element attributes cube the temporal behavior of the presentation The"smil element can have the follwing attribute: sanhe the Layout of the presentation on a screen 3. associate hyperlinks with media objects This attribute uniquely identifies an element within a document. Its vab e is an XML identifier This specification is structured as follows The'smil"element can contain the following children this Section defines the time model us Table of Contents · I Specificaton Apom 3 The Document Head 3.1 The head Element 03 The head elems组 The "headelement contains information that is not related to the temporal behavior of the presentation l language Element attributes The rnt lyouL Fement ·4Te 2 enar Element 0 42.3 Meda Obing Element: The ref, animation, audio, img, video, text and textstream Element Content The"headelement can contain the follow ing chiren: a 4.2.4 SMIL. Time Molel 4.2.4.2 Determining Values of Model Valus for SMIL. 1.0 Elcmcnts 04.3 The switch Element Defined in Section 3.2 Defined in SectiN 3.4 swale 口452 The anchor Element The head clement may contain any number of"meta"elements and either a"layout element or a'switch 1 Specification Approach SMiL documents are XML 1.0 documents [XMI1O). The reader is expected to be familiar with the concepts amd 3.2 The layout Element The"element detemines how the elements in the document s body are pasiticool on an abstract rende specification does not rely on part defined in URls surface either visual or acoustic). The syntax of SMIL documents is defined by the DTD in Secion 52. The syntax of an attribute value that cannot temzin.202GhITealuasr
15 5ce时 d Mimed heyen L8q均 P3wsy.Datn2,特的 Spchenured Mutnf lyMon Lingang y: black element(defned in Section 4.3). This can be sed for example to describe the document different h on: absolutel ollowing example shows how CSS2 can be used as altemative to the SMIL basic layout language(defined in Section 3 3 regiens'r'l I top: 20px: left sition: absolutel root-layout region idar top=20 left= 20/> textarea This section defines a basic layout langaage for SMIL SMIL basic ext region=a'srcs"text, htnI.dur=10s"/> oduces the"fit attribute LCSS2] The reader is expected to be far the SMIL basic layout only controls the layout of media object elements(defined in Section 4.2 3). It is illegal lo use Element Attributes SMIL basic layout for other SMIL element The"region"element can have the following attributes Fixed Property Values The use and definition o this attribute are identical to the "background-color"property in the CSS2 The following stylesheet defines the values of the CSS2 properties"display""position" that are valu in hackground-color attribute is absent, the background is transpar MIL basic layout. These property values are fixed ECTURE%加 TUFTWutinedwSN
Page 5 Tuady, Deceber 7. 192 caNneD Brady reman lague m without this altribute. have a l-l mapping onto a CsS property, but can be simulated in CSS This attribute can have the following vahue tibule values have the same restrictions as the attribute values of the height'altribute. Scale the objects beight and width independenty so that the content just touches all edges of the wid he use and definition of this attribate are identical to the width "property in the CSS2 specification have the same restictions as the attribute values of the heip hidden width)of the media object element is smaller than the height z-index ect starting from the top(elt p lf the intrinsic height (width) of the media cbject element is greater than the heip the objet starting from the wop (ef o If two boxes generated by elements A and b have the same stack level, then edge until the height(width)defined in the"region"element is reached, and clip the I. If the display of an element A starts bater than the display of an element B, the box of time and an element a occurs later in the Scale the visual media object while preserving its aspect rio until its height or width SMIL document text than an element B, the box of A is stacked on top of the box of B tes, while none of the content is document tree order as defined in CSS2). bjects left top comer is positioned at the top-left coordinates of the hox, and empsy space at the scroll A scrolling mechanism should be invoked when the elemen's rendered contents exceed is 3.3.2 The root element Scale the visual media object while preserving its aspect rat that its height or by the height and width atinbutes while some of the conteat may The'noot-layoat"element determines the value of of the root element, which in tum size of the viewport, L presenta ion is rendered. media object is displayed. Overflow width is clipped from the right of the melia abject a document contains more than oee root-layoat element, this is an error, and the docament should not be default value of"fil use and definiton of this attribute an tribute values can bepereentage values, and a vanadia in CSS2. For The 'rool-byoutekement can have the following attributes gth"values, SMIL basic bayou oaly supports pixel uni the px unit qualifier in pixel values(the"px" qualifier is Defined in Secion 3.3.1 beight Defined in ets the height of the root element. Only length values are allowed. required forregion'elements The use and definition of this attribute are identical to the"left"property in the CSS2 specification skip-content Attribute values have the same restrictions as the attribute values of the "beieht'atribute Defined in Section 3.21 The defaul value is zero Defined in Section 3.3.1 COn This attribute is introduced for future extensibility of SMIL.(see Appendix). It is interpreted in the Defined in Section 3.3.1 o If a new element is introduced in a future version of SMIL, and this element allows SMIL. L0 Sas the wilth of de root elment Only length values are allowed ement comtent, the skip-content atnbute contols whether this coatent is Element Content o If an empty element in SMIL version 1.0 becomes noe-emply in a future SMIL version, the skip-contentatnbate controls whether this content is ignore by a SMIL 1 O player, or resa ToC Ia ours an emply clement ment is ignored. lf the value is"false", the content of the element is processed The default value for"skip-content"is"true m间山的间四山加时 This attribute 需二 the element for which it is set. values ntly display the The meta" element can have the following alinibetes It is strongly recom Ire that no element can be ECTUFE2STUFFMmecu SU
Tuangan, Daoe ter 7, I: 99 Fage I Tummy, Recede 7, 1999 SpndroiNd Mameda megaton Langu;e defined in the mcla clement Defined in Secti 4.23 4. 2 Synchronization Elements 4.2. 1 The par Element This attribute identifies the property defined in the meta element "name attribute is required formeta'elements g of heir pre efined in Section 3.3.1 Element Attributes The list of properties is cpen-ended. This specification defines the following properties The'parelemeat can have the following attributes The value of this properly determines the base URI for all relative URls used in the document The value of this property specifies a valid rating label for the document as defined by PICS PICS author The value of this property contains the title of the presentation he attribute can contain the following two types of values nea’ s an emply element. delayvalue delay value is a clock-valee measuring presentation time. Presentation time advances at the 4The Document body can topped, decreased or increased either by user actions, or by the play 4. 1 The body element The semantics of a delay value depend on the eleme The" olins information that is related to the temporal and lin king behavior of the cument. It element(defined in Section 4. 22, see Section 4.24 for a definition of the lempo a If this ancestor is a element (defined in Section 4.2 2 the value defines a delay end of the first lexical pred a synchronization element Figure 4 The clement begins when a certain enent occurs(see Figure 4.3). Its value is an element-event The 'body element can have the follow ing atribute ancestor that is a sy Element Content 2. Remove all"a' and"switch"elements from S. add the children of all "a elements to S. nless they areswitch The"body'element can contain the following children The resulting set S is the set of"in scope elements fined in Section 4. 5.1 wright The copyright notice of the content contained in the element. in Section 4.2.1 Defined in Section 4.2 This attribute specifies the explicit duration of an element See Sectiom 4.24 for a definition of its semantics. The attribute value can be a ckck value, or the stn indefinite This attribute specifies the explicit end of an elemeat See Section 4 4 for a definition of its semantics The attribute can contain the same types of attribute values as the"attrit For adefinition of the semantics of this attribute, see Saction 4. 24. The attribute can have the following Defined in Section 42.2 seq Defined in Secting 4, 2.2 For a definition of the semantics of this value, see Section 4.24 switch o idref This atribute value has the following synta Defined in Section 4.23 For a definition of the semantics of this value, see Section 4.24 ideo ”T千制e5MU
Spnthurine Mused y in languge Synchonend Weared degas Laguna For a definition of the semantics of this value, see Section 4.2A DIGIT 10·9 e default value of"endsync"is'last The io einecaeame: 0 0903- 2 0 a. so 30 minutes and 3 seconds ock value: 02: 33= Defined in Sertion 2 sunac ction of the document Its value must be an XML identifier. If no tendering surface with this id is fined in the layout seton, the values of the formatting properties of this element are determined by the 30s= 30 seconds Ims=5 milliseconds The"region"attribute on'parelements cannot be used by the basic layout language for SMiL defined in this specification. It is added for completeness, since it may be required by other layout languages A fraction x with n digit represents the following value: For a definition of the semantics of this attnbute, see Sertion 424. The attribute vahue can be an integer. or the string"indefinite. The default value is Examples: Defined in Section 4A 005s=5. 1/10 seconds= 500 milliseconds efined in Section 4 00: 00.005=5*1/1000 seconds=5 milliseconds Defined in Section 4.4 syseM element even value specifies a particular event in a synchronization element. An element event has the following syntax: Event- source ) Event Defined in Section 44 a"begin' Clock-val |'end tile Defined in Section 44 The Defined in Section 3.3.1 It is strongly recommended that allpar'elements have a"title"attnbute with a meaningful description This event is generated at an element's effective begin Authoring toos shoald ensure that no element can be introdaced into a SMIL document withoul this Example use: begins"dix)(begint clock-val This event is geterated when aclock sociated with an element reaches a particulr value. this Note on Synchronization between Children clack starts ar O at the element s effective begin. For" andse pendent. Take the The accuracy of synchronization between the children in a parallel growp hen the"par element contains two nce the effective begin, or it may give the med a the object. The later may differ from such as audio or video, and cne of them expenences a delay esentation time that elapsed since the objects display was started e.g. due to rendering or A player can show the following synchronization behaviors: It is an eror to use a clock value that excees the value of the effective duration of the element the event. Example use: tegina"id(x) Each child of thepar'element has its own clock, which runs independently of the clocks of other children in the par'clement(see Figure 4.4 b)) This event is generated at the elements effective end Attribute values Clock values have the following syntax The par element can contain the following childreI Full-clock-val I Partial-clock-val I Tirecount-va Defined in Section 4.5.1 animat 1·ns|?; default is"8 Defined in Section 4. 213 Defined in Sectin 42 3 range tro 00 to 59 Defined in Sectin 4.23
Element Content Defined in Section 4. 2.3 clement can cortain the following children seq Defined in Section 4 23 Defined in Section 4.2.3 l in Saction 4.2.3 img in Section 4.2 Defined in Section 4.23 Defined in Section 42.1 All of these elememts may appear multiple times as direct children of a par clement. Define in Section 4. 2.3 Element The children of aseq element fom a temporal sequenc Defined in Scction 4.1 Defined in Scction 4.21 The seg element can have the following atributes Defined in Section 4.2.1 author 4.2.3 Media Object Elements: The ref, animation, audio, Ing, video, text and begin The media object elements allow the inclusion of media objects into a SMIL presentation. Media objects are I in Section 4.2.1 ig a URI) Defined in Sectin 4.2. 1 There are two types of media objects: media objects with an intrinsic duration(e-g videa, audio) (also called 'contimuous media",and media objects without intrinsic duration (e g text, image)(also called"discrete i Defined in Scctisn4.1 media"). Anchors and links can be atached to visual media objects, i.e. media objects rendered on a visual abstract i0421 邮时: sea"elements cannot be used by the basic layout language for smil defined in When playing back a media object, the player must not derive the exact type of the media abject frem the name of completeness, since it may be required by the media object elemenL. Instead, it must rely solely on other sources about the type, such as type information untained in the type"attribute, or the type information communicated by a server or be operating system efined in Section 4.2.1 wever, should make sure that the gro or textstream)is reflected in the element name. This is in order to increase the readability of the SMil When in doubt about the group of a media object, authors should use the generic ref element Defined in Sectin 4 4 system-language efined in Section.4 Media object cements can have the following attributes: abstract Defined in Section 44 Defined in Section 4.2 1 chat cannot di play a particular tmedia-object this attribute specifies altemate text. It is mended that all media cbject elements have an"alt "attribute with a meaningful Defined in Section 4.4 Authoring tools should ensure that no cment can be introduced into a SMIL document without this ailnbute. Defined in Section 3.3.1 is strongly recommended that all"sey,"elements have attle altr Defined in Section 4.21 Authoring lools should ensure that no element can be introduced into a SMIL document altribute Defined in Sectionl 4.2.1 clip-begin H果
ag t3 slap Syrchamd Nan a eg alan larguage Tuesday, Decerbe 7, miss The clip-begin attnbute specifies the beginning of a sub-clip of a continuous melia object as offset from efined in Section 4 start of the media object alues in the clip -begin atribute have the following syntax Defined in Section +4 Defined in Section 4.4 efined in Section 44 stem. screen-sIZe Defined in Stion 44 alue of this atr bute consists of a metric specifier, followed by a time value whose syntax and semantics depend on the metric specifier. The following formats are allowed: commended that all media obiect element have a title attribute with a meaning ng tools should ensure that mo element can be i have the following values smple-J0-drnp alues indicate the use af the"SMPTE 30 difference between 30 and 29.97 frames per second is handled by dropping the first two Media Objec Elements can contain the following element ne indices (values 00 and 01)of every minute, except every tenth hor The'frames"field in the time specification can assame the values O through24 Defined in Section 45.2 4.2.4 SMIL Time Model 4.241 Time ModelⅤals clip-beginasmpte=10: 12: 33: 20 In the following discussion, the term 'element"refers to synchonization elements only Narmal Play Time expresses time in terms of SMIL cick values. The metric specifier isnpt For each element we define the implicit, explicit, desired, and effective begin, duration, and end Exampl clip-begina'mpt=123.455 The effective begin/end specify what the reader of the document will perceive p-beginanpt=12: 05: 35.3 and desired values are auxiliary values used to define he effective values. The rules for calculating each of these values for the elments defined in SMIL 1.0 are described in the next If the value of the"clip-endatnbute exceeds the duration of the meda object, the value is ignored, and the clip end is set equal to the effective end of the media object Exch element in SMIL has an implicit bey 2. Each element can be assigned an epivir beyin by adding a"beginattnbute to the element Defined in Scotia 42.L I is an error if the explicit begin is earlier than the implicit begin of the element. Defined in Section 4.21 4. Each element can be assigned an explicit end by adding an'endatribute to the element For a definition of the semantics of this a Lnbule Sce Section 42.4. The attribute can have the vlues end a 'value cf explicit-end id Defined in Section 5. The duration of an element is the differen 6. Each element in SMIL can be assigned an eap irit dorati ngaduraltnbus dur s.value of explicit -duration wide information abdut the anchor's contents. 7. The desired begin of an element is equal to Ibe explicit begin if one is given, otherwise the desired begin regon 8. Each eknent has a devired ewf The value of the sr tribute is the URl of the media objec. Thedesired duration of an element is the difference between the desired end and the desired begin 10. Each element has an efective begin LECTUFE 205TU-FWuhmedSNL
