1. SCA3103 - Introduction to Multimedia
Semester /03
Introduction to Multimedia
Lecture 1

2. Introduction to Multimedia
4/26/2017 6:56 AM
Introduction to Multimedia
1- What is Multimedia? 2- Multimedia and Hypermedia 3- World Wide Web 4- Overview of Multimedia Software Tools

3. What Is Multimedia ? Multi Media Multimedia Multi
refer to many or multiple
Media
Vehicle or agent to convey for something
Example: air for sound, writing for words
Computer is a medium for ideas and information
- Express and communicate these ideas
- Store and manipulate information in many different forms

4. The big picture Multimedia Systems Distributed Multimedia Systems
Authoring
Media asset management
Tools
Frameworks
Image
Text
Speech
Audio
Video
Network
Virtual worlds
Streaming video
Web pages
Streaming audio
Client-server

5. GLOBAL STRUCTURE OF Multimedia
4/26/2017 6:56 AM
GLOBAL STRUCTURE OF Multimedia

6. GLOBAL STRUCTURE OF Multimedia
4/26/2017 6:56 AM
GLOBAL STRUCTURE OF Multimedia
Application domain : provides functions to the user to develop and present multimedia projects. This includes Software tools, and multimedia projects development methodology. System domain : including all supports for using the functions of the device domain, e.g., operating systems, communication systems (networking) and database systems. Device domain : basic concepts and skill for processing various multimedia elements and for handling physical device.

7. What Is Multimedia ? Multimedia Multimedia Systems
Presentation of a computer application
Incorporating media elements such as text, graphics, video, animation and sound on a computer.
Multimedia Systems
the computer and software systems that are used in multimedia environments
Interactive control
Distributed multimedia systems
operate over some form of network infrastructure

8. 4/26/2017 6:56 AM
What Is Multimedia ?
When different people mention the term multimedia, they
often have quite different, or even opposing, viewpoints.
A PC vendor: a PC that has sound capability, a DVD-ROM drive , and perhaps the superiority of multimedia-enabled microprocessors that understand additional multimedia instructions.
A consumer entertainment vendor: interactive cable TV with hundreds of digital channels available, or a cable TV-like service delivered over a high-speed Internet connection.
A Computer Science (CS) student: applications that use multiple modalities, including text, images, drawings (graphics), animation, video, sound including speech, and interactivity.

9. Multimedia and Computer Science:
4/26/2017 6:56 AM
Multimedia and Computer Science:
Graphics, visualization, computer vision, data compression, graph theory, networking, database systems.
Components(elements) of Multimedia
Multimedia involves multiple modalities of text, audio,
Images, drawings, animation, and video

10. A brief history of multimedia
World Wide Web
Future
Digital Audio and Video
1990
32 bit
CD-ROM, Local and Wide Area Networking
16 bit processors
Desktop Computer
Graphical Operating Systems
1980
1970-an
8 bit processor

11. Modern multimedia PCs 3D graphics cards with 64 MB of graphics memory
64 note sound cards with wavetable synthesis
256 MB of main memory
60+ GB hard disk space
50+ speed CD readers
56 Kb/s modem or ISDN connection

12. Multimedia Industry Structure
Content
(Media)
Applications
(Software)
Platforms
(Hardware)
Networking
Level 1
Level 2
Level 3
Level 4

13. Multimedia Industry Structure
Level 1
Consists of MM content providers, for example the news industry, the television industry and the entertainment industry.
Level 2
- Consists of multimedia application developers.
Applications include distance learning, desktop videoconferencing, multimedia kiosks, entertainment and imaging.
Level 3
- Consists of MM platform builders.
- These builders include Silicon Graphics, Sun, Intel, Apple, and other hardware vendors.

14. Multimedia Industry Structure
Level 4
- The network infrastructure.
- There are two very different networking environments that will use
MM applications:
- business networks and
- the emerging public networks.

15. Why Apply Multimedia Technology
Ease of use
Intuitive Interface
Immersive Experience
Self-Paced Interaction and Better Retention
Better Understanding of the Content
Cost Effectiveness
More Fun = Greater Efficiency

16. Multimedia Development
Input
Output
Process
Apply effect filters and transforms
Compress or decompress
Convert between formats
Present
Save to a file
Send across the network
Capture from device
Read from a file
Receive over the network

17. Examples of multimedia systems
Content delivery system examples:
Television/(radio?) (old, basic system)
Web/Internet type
Mobile (radio networks)
Content distribution type examples:
Music
Movies (audio/visual content
Games
Virtual worlds (Check Second life on the Web)
eBooks? eMagazines? eNewspapers?

18. Multimedia Application
A Multimedia Application is an application which uses a collection of multiple media sources e.g. text, graphics, images, sound/audio, animation and/or video.

19. Multimedia System Desirable Features
Speci Very High Processing Power
al Hardware/Software needed
Efficient and High I/O
Large Storage and Memory
High Speed Network Support

20. Components of a Multimedia System
Capture devices
e.g. Video Camera, Microphone, Digitising/Sampling Hardware, etc.
Storage Devices
e.g. Hard disks, CD-ROMs, DVD, etc
Communication Networks
e.g. Ethernet, Internets, etc.
Computer Systems
e.g. Multimedia Desktop machines, Workstations
Display Devices
e.g. CD-quality speakers, HDTV, Hi-Res monitors, Color printers etc.

21. Multimedia Data: Text Text Input: keyboard
Stored and input character by character.
Storage of text is 1 or 2 bytes per character.
Other forms of data (e.g. Spreadsheet files, XML) may store format as text (with formatting).
Format: Raw text or formatted text e.g HTML, Rich Text Format (RTF), Word or a program language source

22. Multimedia Data: Text Text (cont.)
Not temporal — BUT may have natural implied sequence e.g. HTML format sequence, Sequence of Java program statements.
Size Not significant compared with other multimedia data.

23. Formatted Text

24. Multimedia Data: Images
Still pictures which (uncompressed) are represented as a bitmap (a grid of pixels).
Input: Digital camera, scanner or generated by graphics editor programs (e.g. Paint)
Analog sources will require digitising.
Stored at 1 bit per pixel (Black and White), 8 Bits per pixel (Grey Scale, Color Map) or 24 Bits per pixel (True Color)

25. Multimedia Data: Images
Images (Cont.)
Size: a 512x512 Grey scale image takes up 1/4 Mb, a 512x bit image takes 3/4 Mb with no compression.
Storage increases with image size
Compression is commonly applied

26. Image : PNG File Format

27. Multimedia Data: Vector Graphics
Format: constructed by the composition of primitive objects such as lines, polygons, circles, curves and arcs.
Input: usually generated by a graphics editor program (e.g. Freehand)
Vector Graphics are usually editable or revisable (unlike Images).
Standards : SVG, OpenGL, WMF, etc.
Do not take up a very high storage overhead.

28. Multimedia Data: Vector Graphics
Vector Graphics (Cont.)
Advantages: reduction of data size, meaningful representation, easier manipulation, resizable without losing quality .
Disadvantages: not suitable for reproducing photographs or paintings, take a long time to display complex image.

29. Vector Graphics vs Images
Graphic (WMF) : bytes
Image (BMP) : bytes
enlarge
enlarge

30. Vector Graphics Examples

31. Multimedia Data: Audio
Audio signals are continuous analog signals.
Input: microphones and then digitised and stored
usually compressed.
CD Quality Audio requires 16-bit sampling at 44.1 KHz
1 Minute of Mono CD quality audio requires 5 Mb.

32. Multimedia Data: Video
Input: usually captured by a video camera.
There are a variety of video (analog and digital) formats
Raw video can be regarded as being a series of single images.
There are typically 25, 30 or 50 frames per second.
a 512x512 size monochrome video images take 25*0.25 = 6.25Mb for a minute to store uncompressed.
Digital video clearly needs to be compressed.

33. Multimedia Delivery Offline Online
Use removable storage as medium delivery
Examples : CD-ROM, PC, DVD
Online
Use a network to send information
Examples : WWW
Enables delivery live multimedia content.
Examples : Video Conferencing, broadcast Multimedia

34. Data Transfer over the Internet
kbits/s
6KB Text File
100KB Image
4MB Movie
GSM Data
9.6
4.5
84 Seconds
56 Minutes
Slow Modem
14.4
3 Seconds
56 Seconds
37 Minutes
GPRS
36.6
1.25 Seconds
22 Seconds
15 Minutes
Fast Modem 56
1 Second
14 Seconds
9 Minutes
ISDN
128
<1 Second
6 Seconds
4.3 Minutes
T1 Leased Line
1544
21 Seconds
ADSL (Typical)
6000
5 Seconds

35. Multimedia and Hypermedia
4/26/2017 6:56 AM
Multimedia and Hypermedia
A hypertext system:
meant to be read nonlinearly, by following links that point to other parts of the document, or to other documents.
HyperMedia:
not constrained to be text-based, can include other media, e.g., graphics, images, and especially the continuous media | sound and video.
- The World Wide Web (WWW) | the best example of ahypermedia application.
Multimedia
means that computer information can be represented through audio, graphics, images, video, and animation
in addition to traditional media.

36. Typical present multimedia applications include(Examples of ):
- Digital video editing and production systems.
- Electronic newspapers/magazines.
- World Wide Web.
- On-line reference works: e.g. encyclopedias, games, etc.
- Home shopping.
- Interactive TV.
- Multimedia courseware.
- Video conferencing.
- Video-on-demand.
- Interactive movies.

37. 3 World Wide Web The W3C has listed the following goals for the WWW:
4/26/2017 6:56 AM
3 World Wide Web
The W3C has listed the following goals for the WWW:
1. Universal access of web resources (by everyone every-
where).
2. Eeffctiveness of navigating available information.
3. Responsible use of posted material.
History of the WWW
Charles Goldfarb et al. developed the Generalized
Markup Language (GML) for IBM.
The ISO released a nal version of the Standard Generalized Markup Language (SGML).

38. 1990 - Tim Berners-Lee invented the HyperText Markup
4/26/2017 6:56 AM
Tim Berners-Lee invented the HyperText Markup
Language (HTML), and the HyperText Transfer
Protocol (HTTP).
NCSA released an alpha version of Mosaic based on
the version by Marc Andreessen for X-Windows |
the first popular browser.
Marc Andreessen et al. formed Mosaic Communications Corporation | later the Netscape Communications Corporation.
The W3C accepted XML version 1.0 specifications
as a Recommendation | the main focus of the W3C
and supersedes HTML.

39. HTTP (HyperText Transfer Protocol)
4/26/2017 6:56 AM
HTTP (HyperText Transfer Protocol)
HTTP: a protocol that was originally designed for transmit-
ting hypermedia, but can also support the transmission of
any le type.
HTTP is a stateless request/response protocol: no information carried over for the next request.
The basic request format:
Method URI Version
Additional-Headers:
Message-body
The URI (Uniform Resource Identifier): an identifier for the
resource accessed, e.g. the host name, always preceded by
the token \
Two popular methods: GET and POST.

40. HTML (Hyper Text Markup Language)
4/26/2017 6:56 AM
HTML (Hyper Text Markup Language)
HTML: a language for publishing Hypermedia on the World
Wide Web | defined using SGML:
1. HTML uses ASCII, it is portable to all dierent (possibly
binary incompatible) computer hardware.
2. The current version of HTML is version 4.01.
3. The next generation of HTML is XHTML | a reformulation of HTML using XML.
HTML uses tags to describe document elements:
- <token params> | defining a starting point,
- </token> | the ending point of the element.
- Some elements have no ending tags.
Naturally:
HTML has more complex structures and can be mixed in with other standards.

41. XML (Extensible Markup Language)
4/26/2017 6:56 AM
XML (Extensible Markup Language)
XML: a markup language for the WWW in which there is
modularity of data, structure and view so that user or application can be able to define the tags (structure).
Example of using XML to retrieve stock information from a
database according to a user query:
1. First use a global Document Type Definition (DTD) that
is already defined.
2. The server side script will abide by the DTD rules to
generate an XML document according to the query using
data from your database.
3. Finally send user the XML Style Sheet (XSL) depending
on the type of device used to display the information.

42. The following XML related specications are also standardized:
4/26/2017 6:56 AM
The following XML related specications are also standardized:
XML Protocol: used to exchange XML information between processes.
- XML Schema: a more structured and powerful language
for defining XML data types (tags).
- XSL: basically CSS for XML.
- SMIL: synchronized Multimedia Integration Language, pronounced \smile"|a particular application of XML (glob-
ally predefined DTD) that allows for specification of interaction among any media types and user input, in a
temporally scripted manner.

43. SMIL (Synchronized Multimedia IntegrationLanguage)
4/26/2017 6:56 AM
SMIL (Synchronized Multimedia IntegrationLanguage)
Purpose of SMIL: it is also desirable to be able to publish
multimedia presentations using a markup language.
- A multimedia markup language needs to enable scheduling
and synchronization of different multimedia elements, and
define their interactivity with the user.
- The W3C established a Working Group in 1997 to come up
with specifications for a multimedia synchronization language | SMIL 2.0 was accepted in August 2001.

44. 4/26/2017 6:56 AM
SMIL 2.0 is specified in XML using a modularization approach similar to the one used in xhtml:
1. All SMIL elements are divided into modules | sets of
XML elements, attributes and values that define one conceptual functionality.
2. In the interest of modularization, not all available modules
need to be included for all applications.
3. Language Profiles: species a particular grouping of
modules, and particular modules may have integration requirements that a profile must follow.
- SMIL 2.0 has a main language profile that includes almost all SMIL modules.

45. Overview of Multimedia Software Tools
4/26/2017 6:56 AM
Overview of Multimedia Software Tools
The categories of software tools briefy examined here are:
1. Music Sequencing and Notation
2. Digital Audio
3. Graphics and Image Editing
4. Video Editing
5. Animation
6. Multimedia Authoring

46. Music Sequencing and Notation
4/26/2017 6:56 AM
Music Sequencing and Notation
Cakewalk: now called Pro Audio.
- The term sequencer comes from older devices that stored
sequences of notes (\events", in MIDI).
- It is also possible to insert WAV les and Windows MCI
commands (for animation and video) into music tracks
(MCI is a ubiquitous component of the Windows API.)
Cubase: another sequencing/editing program, with capabilities similar to those of Cakewalk. It includes some digital
audio editing tools.
Macromedia Soundedit: mature program for creating audio for multimedia projects and the web that integrates well
with other Macromedia products such as Flash and Director.

47. 4/26/2017 6:56 AM
Digital Audio
Digital Audio tools deal with accessing and editing the actual sampled sounds that make up audio:
- Cool Edit: a very powerful and popular digital audio
toolkit; emulates a professional audio studio |multi track
productions and sound le editing including digital signal
processing effects.
- Sound Forge: a sophisticated PC-based program for
editing audio WAV files.
- Pro Tools: a high-end integrated audio production and
editing environment | MIDI creation and manipulation;
powerful audio mixing, recording, and editing software.

48. Graphics and Image Editing
4/26/2017 6:56 AM
Graphics and Image Editing
Adobe Illustrator: a powerful publishing tool from Adobe.
Uses vector graphics; graphics can be exported to Web.
Adobe Photoshop: the standard in a graphics, image processing and manipulation tool.
- Allows layers of images, graphics, and text that can be separately
manipulated for maximum flexibility.
- Filter factory permits creation of sophisticated lighting-effects file-ters.
Macromedia Fireworks: software for making graphics specifically for the web.
Macromedia Freehand: a text and web graphics editing
tool that supports many bitmap formats such as GIF, PNG,
and JPEG.

49. 4/26/2017 6:56 AM
Video Editing
Adobe Premiere: an intuitive, simple video editing tool for
nonlinear editing, i.e., putting video clips into any order:
- Video and audio are arranged in \tracks".
- Provides a large number of video and audio tracks, super-
impositions and virtual clips.
- A large library of built-in transitions, filters and motions
for clips ) effective multimedia productions with little
effort.
Adobe After Eects: a powerful video editing tool that
enables users to add and change existing movies. Can add
many effects: lighting, shadows, motion blurring; layers.
Final Cut Pro: a video editing tool by Apple; Macintosh
only.

50. Animation Multimedia APIs:
4/26/2017 6:56 AM
Animation
Multimedia APIs:
Java3D: API used by Java to construct and render 3D
graphics, similar to the way in which the Java Media
Framework is used for handling media files.
1. Provides a basic set of object primitives (cube, splines,
etc.) for building scenes.
2. It is an abstraction layer built on top of OpenGL or
DirectX (the user can select which).
DirectX : Windows API that supports video, images, audio and 3-D animation
OpenGL: the highly portable, most popular 3-D API.
3D Studio Max: rendering tool that includes a number of
very high-end professional tools for character animation,
game development, and visual effects production.

51. 4/26/2017 6:56 AM
Multimedia Authoring
Macromedia Flash: allows users to create interactive movies
by using the score metaphor, i.e., a timeline arranged in parallel event sequences.
Macromedia Director: uses a movie metaphor to create interactive presentations | very powerful and includes a built in scripting language, Lingo, that allows creation of complex interactive movies.
Authorware: a mature, well-supported authoring product
based on the Iconic/Flow-control metaphor.
Quest: similar to Authorware in many ways, uses a type
of flowcharting metaphor. However, the flowchart nodes
can encapsulate information in a more abstract way (called
frames) than simply subroutine levels.

52. 4/26/2017 6:56 AM
SET OF TOOLS

53. Questions

54. Q1) When designing multimedia systems, what two levels of functionality need to be considered? Briefly define these levels.
There are two levels of description for an application:
* Functional level -- what the application does and source and display data formats. E.g. An application may deal with the retrieval and display of movies. It retrieves movies and displays them in a window.
* System Level -- The entities that the application deals with and how it deals with them. In the above example we deal with video frames and voice samples and need to process these accordingly.

55. Q2) For each common multimedia data type discuss what common functionalities should be supported by a multimedia system.  
The following functionality should be provided by a multimedia system:
Digital Representation of Media --
Many standardised formats for many media
Capture: Digitisation of Media --
special Hardware/Software
Creation and editing –
assemble media and alter it
Storage Requirements –
significant for multimedia
Compression --
related to above and below, ie can save on storage but can hinder retrieval
Structuring and retrieval methods of media –
simple to advanced DataBase Storage
Display or Playback methods --
effect of retrieval must view data
Media Synchronisation --
display multimedia as it is intended

56. Typical Range of operations required for common media include: Text Editing Formatting Sorting Indexing Searching ncrypting The above operations involve basic processing such as: Character Manipulation String Manipulation Audio Audio Editing Synchronisation Conversion/Translation Filtering/ Sound Enhancing Operators Compression Searching Indexing Sample Manipulation Waveform Manipulation

57. Graphics
Graphic primitive Editing Shading Mapping lighting Viewing
Rendering Searching Indexing
The above operations involve basic processing such as:
Primitive Manipulation
Structural/Group Manipulation
Image
Pixel operations Geometric Operations Filtering Conversion
Indexing Compression Searching
Pixel Manipulation
Area Manipulation, copy image areas, delete area, process areas of interest

58. Animation -- Primitive/Group Editing Structural Editing Image Overlaying Rendering Synchronisation Searching Indexing The above operations involve basic processing such as: Pixel Manipulation Area Manipulation, copy image areas, delete area, process areas of interest Frame Manipulation, Copy frame(s) to frame(s), Process frame(s)

59. Video --
Pixel Operations Frame Operations Editing Synchronisation
Conversion Mixing Indexing Searching Video Effects/Filtering
The above operations involve basic processing such as:
Pixel Manipulation
Area Manipulation, copy image areas, delete area, process areas of interest b
Frame Manipulation, Copy frame(s) to frame(s), Process frame(s)

60. q3) You have been commissioned to produce a Multimedia mail system
q3) You have been commissioned to produce a Multimedia mail system. What media should be supported in such a mail system and how should an application facilitate assembly, delivery and reading of the mail? SKECTH OF SOULTIOIN REALISATION OF BANDWIDTH/MESSAGE SIZE and how deal with it important. Also how the application deals with media is important. Multimedia mail an extension of test-only mail: Basic content still test Annotated with richer media: Image Speech/Audio Video Clip

61. Possible problems Send all data at once ---- large mail message High Bandwidth High Server Overheads Mailboxes need large storage Mail apps need large memory Low quality audio and images not a problem if small in number? Terminal being used the read mail supports all media? Printing etc may lose their Message

62. Solution Annotations (tags/links) in main body Annotations can be sent with main message (Explicit Media Inclusion)OR Get requested specifically by recipient when message is read or indeed if media is required.(Implicit Media Inclusion) Latter method allows reading of mail on more platforms etc Could send previews of data (i.e. lower resolution audio, images, image snapshots of video, thumbprints of larger media?) Application Requirements Multimedia enabled Good user friendly Interface Good network connection Good media support of formats Input ---- support for Multimedia Authoring Input ---- support for Graphics/Image/Audio/Video input devices

63. Q4) What is meant by the terms Multimedia and Hypermedia
Q4) What is meant by the terms Multimedia and Hypermedia? Distinguish between these two concepts.
Multimedia ---- An Application which uses a collection of multiple media sources e.g. text, graphics, images, sound/audio, animation and/or video.
Hypermedia --- An application which uses associative relationships among information contained within multiple media data for the purpose of facilitating access to, and manipulation of, the information encapsulated by the data.

64. Q5) What is meant by the terms static media and dynamic media
Q5) What is meant by the terms static media and dynamic media? Give two examples of each type of media.
Static Media – does not change over time, e.g. text, graphics
Dynamic Media --- Time dependent (Temporal), e.g. Video, sound, animation.

65. q6) Give a definition of multimedia and a multimedia system
q6) Give a definition of multimedia and a multimedia system? Multimedia is the field concerned with the computer-controlled integration of text, graphics, drawings, still and moving images (Video), animation, audio, and any other media where every type of information can be represented, stored, transmitted and processed digitally. A Multimedia System is a system capable of processing multimedia data and applications.

66. Q7) What are the key distinctions between multimedia data and more conventional types of media? Multimedia systems deal with the generation, manipulation, storage, presentation, and communication of information in digital form. - The data may be in a variety of formats: text, graphics, images, audio, video. - A majority of this data is large and the different media may need synchronisation -- the data may have temporal relationships as an integral property. - Some media is time independent or static or discrete media: normal data, text, single images, graphics are examples. - Video, animation and audio are examples of continuous media

67. Q8) What key issues or problems does a multimedia system have deal with when handling multimedia data? A Multimedia system has four basic characteristics: Multimedia systems must be computer controlled. Multimedia systems are integrated. The information they handle must be represented digitally. The interface to the final presentation of media is usually interactive.

68. Multimedia systems may have to render a variety of media at the same instant -- a distinction from normal applications. There is a temporal relationship between many forms of media (e.g. Video and Audio. There 2 are forms of problems here Sequencing within the media -- playing frames in correct order/time frame in video Synchronisation -- inter-media scheduling (e.g. Video and Audio). Lip synchronisation is clearly important for humans to watch playback of video and audio and even animation and audio. Ever tried watching an out of (lip) sync film for a long time?

69. The key issues multimedia systems need to deal with here are: How to represent and store temporal information. How to strictly maintain the temporal relationships on play back/retrieval What process are involved in the above. Data has to represented digitally so many initial source of data needs to be digitise -- translated from analog source to digital representation. The will involve scanning (graphics, still images), sampling (audio/video) although digital cameras now exist for direct scene to digital capture of images and video. The data is large several Mb easily for audio and video -- therefore storage, transfer (bandwidth) and processing overheads are high. Data compression techniques very common.

70. Q9) Briefly describe eight hardware or software features that a Multimedia System should possess. The following features should be present: o Very High Processing Power  needed to deal with large data processing and real time delivery of media. Special hardware commonplace. o Multimedia Capable File System  needed to deliver real-time media -- e.g. Video/Audio Streaming. Special Hardware/Software needed e.g RAID technology. o Data Representations/File Formats that support multimedia  Data representations/file formats should be easy to handle yet allow for compression/decompression in real-time.

71. Efficient and High I/O  input and output to the file subsystem needs to be efficient and fast. Needs to allow for real-time recording as well as playback of data. e.g. Direct to Disk recording systems. o Special Operating System  to allow access to file system and process data efficiently and quickly. Needs to support direct transfers to disk, real-time scheduling, fast interrupt processing, I/O streaming etc. o Storage and Memory  large storage units (of the order of Gb or more) and large memory ( Mb or more). Large Caches also required and frequently of Level 2 and 3 hierarchy for efficient management. o Network Support  Client-server systems common as distributed systems common. o Software Tools  user friendly tools needed to handle media, design and develop applications, deliver media.

72. q10) The main types of multimedia data are: graphics, images, audio, s and video. What technical issues are associated when these data types are integrated in a Multimedia System? For each media type briefly relate to the issues involved in generating, capturing, storing and transmitting the respective media components.

73. Multimedia issues :
o Sequencing within the media -- playing frames in correct order/time frame in video
o Synchronisation -- inter-media scheduling
o How to represent and store temporal information.

74. Data Types: Graphics Source: Graphics input devices include: keyboard (for text and cursor control), mouse, trackball or graphics tablet. Storage: Graphics are usually constructed by the composition of primitive objects such as lines, polygons, circles, curves and arcs. Graphics are usually generated by a graphics editor program ( e.g. Freehand) or automatically by a program ( e.g. Postscript usually generated this way). Graphics are usually editable or revisable (unlike Images). Transmission: Graphics files usually store the primitive assembly and do not take up a very high overhead for bandwidth (e.g. Flash Vector Graphics)

75. Images Source: Images may be generated by programs similar to graphics or animation programs. But images may be scanned for photographs or pictures using a digital scanner or from a digital camera. Some Video cameras allow for still image capture also. Analog sources will require digitising. Storage: Images may be stored at 1 bit per pixel (Black and White), 8 Bits per pixel (Grey Scale, Colour Map) or 24 Bits per pixel (True Colour). Thus a 512x512 Grey scale image takes up 1/4 Mb, a 512x bit image takes 3/4 Mb with no compression. Transmission: The storage overhead increases with image size so compression is CMP632 Multimedia Systems SOLUTIONS commonly applied at source for bandwidth/storage e.g. JPEG

76. Audio Source: They are first captured by a microphones and then digitised and stored on disk Storage: usually compressed as CD quality audio requires 16-bit sampling at 44.1 KHz. So 1 Minute of Mono CD quality audio requires 60*44100*2 Bytes which is approximately 5 Mb. Transmission/Bandwidth: Maybe be compressed (MPEG) perhaps streamed/copressed (Realaudio). Wav files may not be compressed

77. Video Source:Analog Video is usually captured by a video camera and then digitised. May be digitised at source (Digital Video Camera) Storage: Raw video can be regarded as being a series of single images. There are typically 25, 30 or 50 frames per second. Therefore a 512x512 size monochrome video images take 25*0.25 = 6.25Mb for a minute to store uncompressed. Digital video clearly needs to be compressed. Transmission/Bandwidth: Maybe be compressed (MPEG) perhaps streamed/copressed (Realvideo/Quicktime). 14 Marks Total: Unseen --- Assimilation/Extended reasoning of a few parts of the course

78. Q11) Briefly describe five ways in which content can be formatted and delivered in a Multimedia Authoring System.
1. Scripting (writing)
Standard Text --- say what you want with word
2. Graphics (illustrating)
“A picture is worth a thousand words” say what you want with a graphic illustrations
3. Animation (wiggling)
Now we approach multimedia --- say what you want with a graphic animation or video
4. Audio (hearing)
Sounds can convey alerts, ambience and contents say what you want with a narration
5. Interactivity (interacting)
True mulitedia immerse yourself in am interactive presentation, possibly more instructive. Interactive actions can start animations, audio, move to new parts of presentation, control simulations etc.