hsc ipt multimedia suits nsw syllabus

1. Multimedia
HSC Preparation 2017

2. What is Multimedia?
• the combination of a variety of different media
(data types):
• text and numbers
• audio
• video
• images
• animation
to add interactivity, hypertext and other forms of
hypermedia.

3. What is Interactivity?
• refers to the user being able to
make an immediate response to the
product and modify processes

4. What is Interactivity?
• there is a dialogue between the user
and the input device

5. What is Interactivity?
• this communication may result in
linear or non-linear path through the
product

6. What is Interactivity?
•dynamic interactivity results when
the product changes, depending on the
action taken by either the author
and/or the user
• some products use indexing to
remember position in the product

7. Characteristics of Multimedia
• it can increase the impact of the
message or impact on the user …

8. Characteristics of Multimedia
• multimedia systems involve interactivity
− information on demand, as required,
controlled by the user, can be self-paced,
cross referenced via hyperlinks
− content can be selected by user
learning style (learn by doing)
− involves multi-senses …

9. Characteristics…..
• can involve more than one input device
• can be structured to build on previous
learning
• can have feedback on performance …

10. Characteristics…..
• can be repeated (over and over)
• hyperlinks / hypertext can be utilised
• involves the user in the presentation. ..

11. Characteristics…..
• involves the user in the presentation
• allows input, provides output
• it is generally dynamic, not static.

12. Text
Strings of printable characters separated
by white space characters
(letters, numbers, symbols) …

13. Text
main method of conveying information
through language …

14. Text
•text size / style can be used to emphasis content
• used for titles, headlines, menus, content
• software can ‘speak’ text.

15. Hypertext /Hypermedia
Text presented in such a way that
supports direct, intuitive navigation
between elements of the text of other
information …

16. Hypertext /Hypermedia
Hotspots can also be used : usually termed
hypermedia as they are often linked to
images, video or audio media
• text / hotspots are linked with other cards / pages/ documents

17. Digitising data
Presentation of the product
• CD-ROM, DVD, Video &
Online …

18. Digitising data
• Analog v Digital
• size and type of files
• quality of product …

19. Digitising data
• timing sequence
• planning – storyboards …

20. Lossy vs Lossless
• Lossy compression removes a number of
data bytes from a file.
The resulting file is smaller in size but the
quality is reduced
• However, audio and video files can be
compressed with high compression ratios and
without any change noticable to the
human ear or eye.

21. Lossy vs Lossless
• Lossless compression allows the
original file to be recovered in full.
It works by replacing repeated data
with something that takes up less room.

22. Images - Bitmapped vs Objects
• BITMAPPED
• a section of memory consisting of a
series of zeroes and ones corresponding
to pixels on the screen
• for colour, a number of bits are used to
represent the colour value of each pixel

23. Images - Bitmapped vs Objects
• BITMAPPED..
• a correspondence between memory
locations and elements of the output
pattern on various output devices
• the frame buffer is a section of memory
used to store that data for the current
image being displayed….

24. • Bitmapped images usually require
anti-aliasing to remove ‘jaggies’
• Jaggies - the staircase roughness of
oblique lines and polygon edges in
computer images caused by the underlying
squareness of the pixel

25. • Bitmapped images usually require anti-aliasing to remove
‘jaggies’
• Anti-aliasing - the process of removing
faults such as jaggies in computer images
caused by the physical size and shape of
the pixel.

26. • OBJECTS / VECTOR
• stored as mathematical entities, eg.
Coordinates, width, colour, intensity etc
• the vectors are defined only by their
starting and finishing points

27. • OBJECTS / VECTOR
• vector graphics are also known as
objects
• typically these images are smaller in
file size and easily scaled than
bitmapped images.

28. Dithering
• Dithering - the representation of a
colour not available in the existing palette
by the use of a pattern of varying colours
where the eye performs the averaging to
produce the required colour.

29. Dithering
• a Mask can be used to protect an image
and not allow editing
• to alter the size of the file, combinations
of colour palette and dithering can be used

30. Common Image File Types

31. Optimising an Image File
With internet images, the goal is
generally to have maximum image
quality with minimum file size.
Optimising an image refers to the
process of balancing various
compromises in order to achieve
this goal. …

32. Optimising an Image File
File size is determined by two main
factors:
Image Size (Resolution)
This is determined by the number of
pixels in the image. The bigger the
image, the more pixels it has and the
larger the file size. …

33. Optimising an Image File
File size is determined by two main factors:
To optimise the image size we will
crop and/or resize the image. …

34. Optimising an Image File
File size is determined by two main factors:
Image Quality (Compression)
JPG and GIF are both "compressed"
formats, which means you can lower
the file size by reducing image quality.
Note that GIF and JPG files are handled
differently when it comes to
compression….

35. Optimising an Image File
File size is determined by two main factors:
Image Quality (Compression)
JPG and GIF are both "compressed" formats, which means you can lower
the file size by reducing image quality. Note that GIF and JPG files are
handled differently when it comes to compression.
To optimise jpg files we will
compress them.
To optimise GIF files we will
reduce the number of colours.

36. Digitised Audio
the quality of the sound depends on the
sampling rate, sampling size, time and
number of channels …

37. Digitised Audio

38. Digitised Audio
• sampling rates are from 10 to 44 kHz with CD-ROM
having a sampling rate of 33kHz
• slow rates result in loss of quality and distortion
• sampling size refers to how many bits are
used to record (bit resolution)…

39. Digitised Audio
• sampling rates are from 10 to 44 kHz with
CD-ROM having a sampling rate of 33kHz
• slow rates result in loss of quality and
distortion

40. • 16 bits gives 65536 possible level of sound
• 8 bits gives 256 (and smaller files)
• sound can also be in mono (1 track) or stereo (2
track)
• CD-ROMs are popular storage devices as they
allow direct (non-linear) access.
• 44kHz at 16 bit for 60 sec = 10.5Mb
• 22kHz at 8 bit for 60 sec = 2Mb

41. Audio Compression
•Minimal Hearing Threshold
• the human ear can only receive
sound between 20Hz and 20kHz
• any sound not within this range is
discarded as the information is of no
use ….
•

42. Audio Compression
•Masking Effect
• when you hear sounds, the louder,
more prominent sounds mask the
quieter sounds
• in terms of compressing the sound,
we can remove the quieter sounds
that we cannot distinguish from the
louder sounds …

43. Audio Compression
• Managing Sound Redundancy
• where a sound occurs
simultaneously on both channels, it
is recorded once for both channels
to use, rather than recorded
separately

44. Digitised Audio File Types

45. The MP3 Format (MPEG)
MP3 files are actually MPEG files. But the MPEG
format was originally developed for video by the
Moving Pictures Experts Group. We can say that
MP3 files are the sound part of the MPEG video
format.
MP3 is one of the most popular sound formats for
music recording. The MP3 encoding system
combines good compression (small files) with high
quality.
Sounds stored in the MP3 format have the
extension .mp3, or .mpga (for MPG Audio).

46. MIDI
• The details of the actual notes played, on, off,
velocity, pitch bend, after touch, program
change, length, tone, etc. are all kept in the file
• MIDI files when played require a MIDI keyboard or
device to interpret the notes and then produce the sound
• MIDI files are used by musicians to multi-track, mix
and write scores
• Hardware required includes controller
(keyboard), synthesiser, MIDI port and a computer
running MIDI software

47. What Format To Use?
The WAVE format is one of the most popular sound
format on the Internet, and it is supported by all
popular browsers. If you want recorded sound
(music or speech) to be available to all your
visitors, you should use the WAVE format.
The MP3 format is the new and upcoming format
for recorded music. If your website is about
recorded music, the MP3 format is the choice of the
future.

48. Video
• Video is real image recording
• usually requires data compression
(CODEC) to allow a smaller file, and
decompression to play

49. Video
• requires high VRAM and storage
space
• typically, 20 minutes of video is 8GB.
Since 1 frame at 24 bit = 1Mb
• file types include MPEG (Lossy) and
Quicktime, AVI (Lossless)

50. • Lossy CODEC’s find data that can
be removed and delete this without
much quality loss thus making the
video smaller

51. •Lossless CODEC’s look for patterns
of pixels replacing them with a code
between each frame

52. • Lossless CODEC’s
•for example: the background may be
stationary and the person moves, so
the background is saved using a code
which represents it, and only changes
when a new background appears

53. •Digital video cameras simplify the process, as
“S” video or firewire ports allow transfer of
digital data between the camera and computer
• to reduce file size the frame rate, screen area,
palette, file type and CODEC can be changed
• Video cards usually allow frames to be
captured (frame grab)
• can be edited via software (including iMovie,
Adobe Premiere, Quicktime, Quicktime VR)

54. Video File Types

55. Animation
A series of still images that have been
manipulated to give the appearance
of movement or life like motion

56. Animation
• the frame rate determines the persistence of
vision and smoothness of image to the user
• 30 frames/sec refresh rate (flicker free)
• 25 f/s PAL
• 24 f/s Movies
• 12 f/s Cartoons
• 8 f/s minimum
• when the animation speed matches the refresh
rate of the screen, the image is flicker free

57. Cell-Based Animation
• Creation of individual images in cells
(frames) which when played produces
motion
• this type of animation is the traditional
method

58. Cell-Based Animation

59. Path-Based Animation
• The start and end point and path for the
object to follow are defined by vectors
• the background is fixed
• saves memory and processing time
especially if the image is an object

60. Path-Based Animation

61. Tweening
• The process of taking two images of
an animation and producing
intermediate images so that the
animation appears smooth

62. Tweening

63. Effects - Morphing
• The process of transforming an
image into a new image that is
different to the start image
• especially in terms of the shape of objects

64. Effects - Morphing

65. Effects - Warping
• The distortion of an image by
mathematical processes

66. Effects - Warping

67. Effects - Dynamic
• Time of day / time of year animations
• this shows changes in lighting (especially sun impact) over the
day or changes over the year at a fixed time of day
• Walk-through animations
• this shows a scene from a succession of different view points
creating the illusion of motion through the scene
• Feature animation
• this modifies scene attributes dynamically
• it can also be used to let objects in a scene appear or disappear
by manipulating their transparency
• this is achieved by rendering several variations of a scene and
interpolating the resulting images

68. Effects - Dynamic...
• Geometry animation
• this is the most complex
• requires changing the geometric elements of a scene
dynamically
• this technique has been used in pictures like
“Terminator II”, “Jurassic Park”, “Toy Story” and many
others
• this is what most people refer to when using the term
animation

69. Compression strategies can take
advantage of 4 kinds of redundancy
• Coding Redundancy
• relies on the fact that not all data will occur
with the same probability
• compression algorithms also use the fact that
it is likely that the same data will often repeat

70. Compression strategies can take
advantage of 4 kinds of redundancy
• Spatial Redundancy
• occurs because pixels which are near each
other are likely to be similar to each other

71. Compression strategies can take
advantage of 4 kinds of redundancy
• Temporal Redundancy
• occurs because pixels in consecutive frames
of a video are likely to be similar
• MPEG takes advantage of this

72. Compression strategies can take
advantage of 4 kinds of redundancy
• Psychovisual Redundancy
• occurs because the human visual system is
better at seeing changes in luminance
(brightness) than in seeing the changes in
chrominance (colour)

73. Information Processes - Collecting
• Collecting involves data being obtained
from a variety of sources
• text and number are gathered digitally
• video, audio, images are gathered via
analog means and then interpreted into
digital form

74. Information Processes - Organising
• The way information is organised in
multimedia product is through storyboarding
and screen design
• when organising there are some steps which
need to be followed:
• determine the intended audience
• create a storyboard
• plan your navigational tools
• create an aesthetically appealing
production

75. Information Processes - Analysing
• Through the analysis stage, data is turned into
useful information
• it involves the testing and retesting of the
multimedia presentation
• different design methods can also be applied
such as top-down design ( high concept broken
down again and again into parts)

76. Information Processes - Storing /
Retrieving
In this information process some things
need to be determined such as:
• initially, data may be stored and
collected in analog from such as videos or
audio tape, or other mediums
• elements may also be stored digitally
such as hard drives, CD-ROMs, DVD
Flash media, tape drives or similar.

77. Information Processes - Storing /
Retrieving
what type of compression techniques will
be used
• how will it be distributed, CD-ROM,
DVD due to high level of production rate
• Will it require Internet distribution?

78. Information Processes - Processing
• Processing is the manipulation of
data
• the individual components that will be
included into a multimedia presentation
need to be processed before being
organised by the multimedia software

79. Information Processes - Processing
• In this information process, all the
elements need to be processed, ie.
Animations created, text formatted,
sound and video being edited and
compressed via CODEC’s (A codec is
software that is used to compress or
decompress a digital media file)

80. Information Processes -
Transmitting and Receiving
• Multimedia delivery is an important decision
• it must be decided whether it will be delivered
via CD-ROM, DVD or the Internet
• depending on the decision, access speed,
bandwidth and other infrastructure will need to
be considered

81. Information Processes - Displaying
• Displaying needs to be considered at
both the hardware level and the software
level
• the method of projection needs to be
considered
-will the production be projected, use
head up displays, touch screens, Mobile
devices?

82. Information Processes - Displaying
•will the production fit on the display, eg.
Navigation, features
• in terms of software, what will the ‘run-
time engine’ (addition s/w required to run
an application) be?
• If delivered on the internet, what is the
lowest common denominator for “plug-
ins”?(a piece of s/w added to a browser
giving additional functionality.)

83. Hardware for displaying
multimedia
CRT screens (VDU)
control 3 focused electron beams (red, green and
blue) which strike pixels off phosphor surface –
glow briefly raster scans in horizontal lines
refresh rate is typically 72 times per second

84. Hardware for displaying
multimedia
LCD (liquid crystal display)
places liquid crystals between two polarising sheets
current applied at various points light, no heat, no
radiation, no glare

85. Hardware for displaying
multimedia
Touch screens
use a matrix of infra-red beams to
locate a finger position
Data projectors
contain a DLP (digital light processor)
with 500,000 separately controlled
mirrors in combination with LCD
technology

86. Hardware for displaying
multimedia
Speakers
use coil of wires to produce a
magnetic field which pulls a cone of
card in and out rapidly to produce
sound
Heads up displays
have image projected onto a helmet
screen

87. Software for creating multimedia
systems
Authoring software
▪ allows creative arrangement of media
elements
▪ often have own computer language
▪ may have web capabilities
▪ Examples: Director, Dreamweaver,
Hyperstudio, Hypercard

88. Software for creating multimedia
systems
Presentation software
▪ allows professional multimedia
communication suitable for
illustration of talks to groups
▪ Example: PowerPoint
Animation software
▪ can create animated GIFs for web
sites, 2D or 3D images as well as
warping and morphing

89. Software for creating multimedia systems
Virtual reality
▪ software can create object or panorama
VR movies..Example: QuickTimeVR
Web browsers
▪ used to display multimedia-based web
pages
▪ abilities can be extended by addition of
plug-ins
▪ Examples: Navigator and Explorer

90. Software for creating multimedia systems
HTML editors
▪ can be used to script multimedia
activity
Word processors
▪ can be used as presentation tools if they
allow inclusion of media other than text
and can display as slide show or
interactive

91. Hardware demands by multimedia
The hardware of a multimedia system
places limits on the quality and size of
the multimedia product that
can be produced or displayed.

92. Hardware demands by multimedia

93. Hardware demands by multimedia

94. Hardware demands by multimedia
.
Calculate the size of the following graphics (answer in Kb to the nearest whole number):
1. A black and white graphic with a resolution of 640 by 480 and 2 tones
2. A colour graphic with a resolution of 1024 by 768 and 64 colours
3. A colour graphic with a resolution of 1600 by 1200 and 256 colours
4. An 8 bit colour graphic with a resolution of 1280 by 1024
5. A 32 bit colour graphic with a resolution of 1152 by 864

95. Hardware demands by multimedia

96. Hardware demands by multimedia

97. Hardware demands by multimedia
Calculate the size of the following audio files (answer in Mb, correct to 2 decimal places):
1. Sampling rate of 22.05 kHz with a 8 bit sound for 2 minutes in stereo
2. Sampling rate of 44.1 kHz with a 16 bit sound for 3 minutes in stereo
3. Sampling rate of 22.05 kHz with a 16 bit sound for 1 minute in mono
4. Sampling rate of 11 kHz with a 8 bit sound for 4 minutes in mono
5. Sampling rate of 44.1 kHz with a 16 bit sound for 10 minutes in stereo

98. Hardware demands by multimedia

99. Hardware demands by multimedia

100. Hardware demands by multimedia

101. Hardware demands by multimedia

102. Multimedia Video Formats

103. Standard video file types
▪ avi
▪ wmv (windows media video - new format)
▪ mpeg
▪ mov (better known as quicktime)
▪ RealVideo
▪ Flash

104. The AVI Format
▪ The AVI (Audio Video Interleave) format
was developed by Microsoft.
▪ The AVI format is supported by all
computers running Windows, and by all
the most popular web browsers. It is a
very common format on the Internet, but
not always possible to play on non-
Windows computers.
▪ Videos stored in the AVI format have the

105. The Windows Media Format
▪ The Windows Media format is developed by Microsoft.
▪ Windows Media is a common format on the Internet, but
Windows Media movies cannot be played on non-
Windows computer without an extra (free) component
installed.
▪ Some later Windows Media movies cannot play at all on
non-Windows computers because no player is available.
▪ Videos stored in the Windows Media format have the
extension .wmv.

106. The MPEG Format
▪ The MPEG (Moving Pictures Expert
Group) format is the most popular format
on the Internet. It is cross-platform,
and supported by all the most popular
web browsers.
▪ Videos stored in the MPEG format have
the extension .mpg or .mpeg.

107. The QuickTime Format
▪ The QuickTime format is developed by
Apple.
▪ QuickTime is a common format on the
Internet, but QuickTime movies cannot be
played on a Windows computer without an
extra (free) component installed.
▪ Videos stored in the QuickTime format
have the extension .mov.

108. The RealVideo Format
▪ The RealVideo format was developed for
the Internet by Real Media.
▪ The format allows streaming of video (on-
line video, Internet TV) with low
bandwidths. Because of the low bandwidth
priority, quality is often reduced.
▪ Videos stored in the RealVideo format
have the extension .rm or .ram.

109. How to reduce size of videos
▪ Shorten length
▪ Reduce resolution
▪ More compression
▪ Drop frame rate
▪ Use video streaming

110. Video Streaming
▪ You see video on-demand (i.e.. it plays
as it downloads).
▪ Essentially you download part of the file
to act as a buffer.
▪ Once you start playing from the buffer,
the file continues to download topping
up the buffer.
▪ However you may need a special server
to stream your media from.
▪ Common streaming formats are
▪ mov, mpeg-4, wmv, ra (real video), flash

111. What is Flash?
▪ Flash is a multimedia graphics program
specially for use on the Web.
▪ Flash enables you to create interactive
"movies" on the Web.
▪ Flash uses vector graphics, which
means that the graphics can be scaled
to any size without losing clarity/quality.
▪ Flash does not require programming
skills and is easy to learn.

112. The Flash (Shockwave) Format
▪ The Flash format was developed by
Macromedia.
▪ The Flash format requires an extra
component to play. This component
comes preinstalled with the latest versions
of Netscape and Internet Explorer.
▪ Videos stored in the Flash format have the
extension .swf.

113. The Flash (Shockwave) Format
▪ Macromedia Flash is an excellent choice
for delivering video on the Internet.
▪ It has better browser penetration and
provides more creative opportunities than
any other video format.
▪ Flash files can include graphics,
animation, video, audio and interactive
material.

114. Flash vs. Animated Images and Java
Applets
▪ Animated images and Java applets are
often used to create dynamic effects on
Web pages.
▪ The advantages of Flash are:
▪ Flash loads much faster than animated
images.
▪ Flash allows interactivity, animated images do
not .
▪ Flash does not require programming skills,
java applets do.

115. The Flash (Shockwave) Format
Flash uses the following file types and extensions:
▪ FLA: Flash file. This is the "master" document file for a
flash project, i.e. the source file you work with in the Flash
authoring program. These files can only be opened with
Flash — not the Flash Player.
▪ FLV: Flash Video. Supported from version 7, FLV files are
the preferred format for delivering video clips via Flash.
▪ SWF: Flash delivery file — the file that end users see. This
is a compressed version of the FLA file which is optimized
for viewing in a web browser, the standalone Flash Player,
or any other program which supports Flash. This file type
cannot be edited in Flash.