Multimedia Systems Overview Ch#1-2-3-4.ppt

Multimedia Systems Introduction,

1. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Chapter 1: What Is Multimedia?

2. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Overview
•Introduction to multimedia
•Applications of multimedia
•Primary delivery methods of multimedia

3. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Introduction to Multimedia
•Multimedia is a combination of text, art,
sound, animation, and video.
•It is delivered to the user by electronic or
digitally manipulated means.
•A multimedia project development requires
creative, technical, organizational, and
business skills.

4. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Introduction to Multimedia
(continued)
•Multimedia becomes interactive multimedia
when a user is given the option of
controlling the elements.
•Interactive multimedia is called hypermedia
when a user is provided a structure of linked
elements for navigation.
•Multimedia developers develop multimedia
projects.

5. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Introduction to Multimedia
(continued)
•Multimedia projects can be linear or
nonlinear.
•Projects that are not interactive are called
linear (e.g. PowerPoint slides and montage).
•Projects where users are given navigational
control are called nonlinear and user-
interactive (e.g. online quizzes, games or
kiosks).

6. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Introduction to Multimedia
(continued)
•Authoring tools are used to merge
multimedia elements into a project .
•These software tools are designed to
manage individual multimedia elements
and provide user interaction.

7. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Applications of Multimedia
•Business - Business applications for
multimedia include presentations training,
marketing, advertising, product demos,
databases, catalogs, instant messaging, and
networked communication.

8. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Multimedia is a very effective presentation and sales
tool that greatly increases viewers’ retention rates.
Applications of Multimedia
(continued)

9. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Applications of Multimedia
(continued)
•Schools - Educational
software can be developed to
enrich the learning process.
The figure on the right shows a selection of
instructional videos used for training emergency
medicine specialists. Such online e-learning provides
a cost-effective vehicle to learn clinical techniques
outside of the hospital setting.

10. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Applications of Multimedia
(continued)
•Home - Most
multimedia
projects reach
homes via
television sets
or monitors
with built-in
user inputs.
Genealogy software such
as Reunion from Leister
Productions lets families
add text, images, sounds,
and video clips as they
build their family trees.

11. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Applications of Multimedia
(continued)
•Public places -
Multimedia will
become available
at stand-alone
terminals or
kiosks to provide
information
and help.
Kiosks in public
places can make
everyday life
simpler.

12. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Delivering Multimedia
•Virtual reality (VR)
–Virtual reality is an extension of multimedia.
–It uses the basic multimedia elements of imagery,
sound, and animation.
–It requires terrific computing horsepower
to be realistic.

13. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Delivering Multimedia (continued)
•Virtual reality (VR) (continued)
–In VR, cyberspace is made up of thousands of
geometric objects plotted in three-dimensional
space.
–The standards for transmitting VR in Virtual Reality
Modeling Language (VRML) documents have been
developed on the World Wide Web.
–VRML documents have the file extension .wrl.

14. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Delivering Multimedia (continued)
•Copper wire, glass fiber, and radio/cellular
technologies also serve a means for
delivering multimedia files across a
network.

15. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Summary
•Multimedia is a combination of text, graphic
art, sound, animation, and video.
•Multimedia projects can be linear or
nonlinear.
•Multimedia projects are often stored on CD-
ROM or DVDs. They can also be hosted on
the Web.

16. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Summary (continued)
•Multimedia is widely used in business,
schools, public places, and at home.
•Virtual reality is an extension of multimedia.

17. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Chapter 2: Text

18. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Overview
•Importance of text in a multimedia
presentation
•Understanding fonts and typefaces
•Using text elements in a multimedia
presentation
•Computers and text
•Font editing and design tools
•Multimedia and hypertext

19. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Importance of Text
in a Multimedia Presentation
•Words and symbols in any form, spoken or
written, are the most common means of
communication.
•Text is a vital element of multimedia menus,
navigation systems, and content.

20. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Factors affecting legibility of text:
–Size
–Background and foreground colors
–Style
–Leading
Importance of Text
in a Multimedia Presentation (continued)

21. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Understanding Fonts and Typefaces
•A typeface is a family of graphic characters,
often with many type sizes and styles.
•A font is a collection of characters of a single
size and style belonging to a particular
typeface family.

22. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Understanding Fonts and Typefaces
(continued)
•The study of fonts and typefaces includes
the following:
–Font styles
–Font sizes
–Cases
–Serif versus sans serif

23. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Font styles include:
–Boldface
–Italic
–Underlining
–Outlining
Understanding Fonts and Typefaces
(continued)

24. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Font sizes
–Font size is measured in points.
–Character metrics are the general measurements
applied to individual characters.
–Kerning is the spacing between character pairs.
–Leading is the space between lines.
Understanding Fonts and Typefaces
(continued)

25. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Cases
–A capitalized letter is referred to as uppercase,
while a small letter is referred to as lowercase.
–Placing an uppercase letter in the middle of a
word is referred to as an intercap.
Understanding Fonts and Typefaces
(continued)

26. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Serif versus sans serif
–A serif is the little decoration at the end of a
letter stroke.
–Serif fonts are used for body text.
–Sans serif fonts do not have a serif at the end
of a letter stroke.
–These fonts are used for headlines and bold
statements.
Understanding Fonts and Typefaces
(continued)

27. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Hypermedia structures
–Links
–Nodes
–Anchors
–Navigating hypermedia structures
Multimedia and Hypertext
(continued)

28. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Links
–Links are connections between conceptual
elements.
–Links are the navigation pathways and menus.
Multimedia and Hypertext
(continued)

29. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Nodes
–Nodes are accessible topics, documents, messages,
and content elements.
–Nodes and links form the backbone of a knowledge
access system.
Multimedia and Hypertext
(continued)

30. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Anchors
–An anchor is defined as the reference from one
document to another document, image, sound,
or file on the Web.
–The source node linked to the anchor is referred
to as a link anchor.
–The destination node linked to the anchor
is referred to as a link end.
Multimedia and Hypertext
(continued)

31. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Navigating hypermedia structures
–The simplest way to navigate hypermedia
structures is via buttons.
–Location markers must be provided to make
navigation user-friendly.
Multimedia and Hypertext
(continued)

32. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Summary
•Text is one of the most important
elements of multimedia.
•The standard document format used
for web pages is called HTML.
•Dynamic HTML uses Cascading Style Sheets
(CSS) for greater control over design.

33. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Summary (continued)
•Multimedia is the combination of text
graphics, and audio elements into
a single presentation.
•A hypertext system enables the user to
navigate through text in a non-linear way.

34. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Chapter 3: Images

35. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Overview
•Creation of multimedia images
•Creation of still images
•Colors and palettes in multimedia
•Image file types used in multimedia

36. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Creation of Multimedia Images
•Before commencing the creation of images
in Multimedia, you should:
–Plan your approach using flow charts
and storyboards.
–Organize the available tools.
–Have multiple monitors, if possible,
for lots of screen real estate.

37. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Creation of Still Images
•Still images may be the most important
element of a multimedia project.
•The type of still images created depends on
the display resolution, and hardware and
software capabilities.

38. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Still images are generated in two ways:
–Bitmaps
–Vector-drawn graphics
Creation of Still Images (continued)

39. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Bitmaps
–Bitmap is derived from the words “bit,” which
means the simplest element in which only two
digits are used, and “map,” which is a two-
dimensional matrix of these bits.
–A bitmap is a data matrix describing the individual
dots of an image.
Creation of Still Images (continued)

40. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Bitmaps are an image format suited for
creation of:
–Photo-realistic images
–Complex drawings
–Images that require fine detail
Creation of Still Images (continued)

41. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Bitmaps
–Bitmapped images are known as paint graphics.
–A bitmap is made up of individual dots or picture
elements known as pixels or pels.
–Bitmapped images can have varying bit and
color depths.
Creation of Still Images (continued)

42. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Available binary Combinations for
Describing a Color
24 bits depth.
Millions of colors.
Dithered to 8 bits.
Adaptive palette
of 256 colors.
Dithered to 8 bits.
Macintosh palette
of 256 colors.
Dithered to 4 bits.
16 colors.
Dithered to 8-bit
gray-scale.
256 shades of gray.
Dithered to 4-bit
gray-scale.
16 shades of gray.
Dithered to 1-bit.
Two colors, black
and white.
Creation of Still Images (continued)

43. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Bitmaps can be inserted by:
–Using clip art galleries
–Using bitmap software
–Capturing and editing images
–Scanning images
Creation of Still Images (continued)

44. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Using clip art galleries
–A clip art gallery is an assortment of graphics,
photographs, sound, and video.
–Clip art is a popular alternative for users who do
not want to create their own images.
–Clip art collections are available on CD-ROMs and
on the Internet.
Creation of Still Images (continued)

45. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
The industry-standard programs for bitmap
painting and editing are:
–Adobe’s Photoshop and Illustrator.
–Corel’s Painter and CorelDraw.
Creation of Still Images (continued)

46. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Capturing and editing images
–Capturing and storing images directly from
the screen is another way to assemble images
for multimedia.
–The PRINT SCREEN key in Windows or the COMMAND-
SHIFT-4 key combination on the Macintosh copies
the screen image to the clipboard.
Creation of Still Images (continued)

47. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Morphing software was used to seamlessly transform the images
of 16 kindergartners. When a sound track of music and voices was
added to the four-minute piece, it made a compelling video about
how similar children are to each other.
Creation of Still Images (continued)

48. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Vector-drawn graphics
–Applications of vector-drawn images
–How vector-drawn images work
–Vector-drawn images versus bitmaps
Creation of Still Images (continued)

49. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Vector-drawn images are used in the
following areas:
–Computer-aided design (CAD) programs
–Graphic artists designing for the print media
–3-D animation programs
–Applications requiring drawing of graphic shapes
Creation of Still Images (continued)

50. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•How vector-drawn images work
–A vector is a line that is described by the location of
its two endpoints.
–Vector drawing makes use of Cartesian
coordinates.
–Cartesian coordinates are numbers that describe
a point in two- or three-dimensional space as the
intersection of the X, Y, and Z axes.
Creation of Still Images (continued)

51. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Vector-drawn images versus bitmaps
–Vector images use less memory space and have
a smaller file size as compared to bitmaps.
–For the Web, pages that use vector graphics
in plug-ins download faster and, when used
for animation, draw faster than bitmaps.
Creation of Still Images (continued)

52. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Vector-drawn images versus bitmaps
(continued)
–Vector images cannot be used for photorealistic
images.
–Vector images require a plug-in for Web-based
display.
–Bitmaps are not easily scalable and resizable.
–Bitmaps can be converted to vector images using
autotracing.
Creation of Still Images (continued)

53. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•3-D drawing and rendering
–3-D animation tools
–Features of a 3-D application
–Panoramas
Creation of Still Images (continued)

54. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Features of a 3-D application
–Modeling - Placing all the elements into
3-D space.
–Extrusion - The shape of a plane surface
extends some distance.
–Lathing - A profile of the shape is rotated
around a defined axis.
Creation of Still Images (continued)

55. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Creation of Still Images (continued)

56. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Rendering - Use of intricate algorithms
to apply user-specified effects
Creation of Still Images (continued)

57. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Colors and Palettes in Multimedia
(continued)
•Understanding natural light and color
–Light comes from an atom where an electron
passes from a higher to a lower energy level.
–Each atom produces uniquely specific colors.
–Color is the frequency of a light wave within the
narrow band of the electromagnetic spectrum,
to which the human eye responds.

58. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Understanding natural light and color
(continued)
–Additive color
–Subtractive color
–Monitor-specific color
–Color models
Colors and Palettes in Multimedia
(continued)

59. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Additive color
–In the additive color method, a color is created by
combining colored light sources in three primary
colors - red, green, and blue (RGB).
–TV and computer monitors use this method.
Colors and Palettes in Multimedia
(continued)

60. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Subtractive color
–In the subtractive color method, color is created by
combining colored media such as paints or ink.
–The colored media absorb (or subtract) some parts
of the color spectrum of light and reflect the others
back to the eye.
Colors and Palettes in Multimedia
(continued)

61. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Subtractive color (continued)
–Subtractive color is the process used to create
color in printing.
–The printed page consists of tiny halftone dots of
three primary colors: cyan, magenta, and yellow
(CMY).
Colors and Palettes in Multimedia
(continued)

62. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Color palettes
–Palettes are mathematical tables that define the
color of pixels displayed on the screen.
–Palettes are called “color lookup tables,” or CLUTs,
on the Macintosh.
–The most common palettes are 1, 4, 8, 16, and
24-bit deep.
Colors and Palettes in Multimedia
(continued)

63. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Dithering:
–Dithering is a process whereby the color value
of each pixel is changed to the closest matching
color value in the target palette.
–This is done using a mathematical algorithm.
Colors and Palettes in Multimedia
(continued)

64. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
These images were dithered in
Photoshop to best fit the 8-bit
palettes of GIF files (Adaptive,
System, or Custom 216 Netscape).
Also shown are JPEG files
compressed with highest and
lowest quality and their actual file
sizes.
Note the subtle differences among
palettes and systems, especially in
the gradient blue background.
•Dithering
Colors and Palettes in Multimedia
(continued)

65. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Image File Types Used
in Multimedia
•Macintosh formats
•Windows formats
•Cross-platform formats

66. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Image File Types Used
in Multimedia (continued)
•Macintosh formats
–On the Macintosh, the most commonly used
format is PICT.
–PICT is a complicated and versatile format
developed by Apple.
–Almost every image application on the
Macintosh can import or export PICT files.
–In a PICT file, both vector-drawn objects
and bitmaps can reside side-by-side.

67. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Windows formats
–The most commonly used image file format on
Windows is DIB, also known as BMP.
•DIB stands for device-independent bitmaps.
–Bitmap formats used most often by Windows
developers are:
•BMP - A Windows bitmap file
•TIFF - Extensively used in DTP packages
•PCX - Used by MS-DOS paint software
Image File Types Used
in Multimedia (continued)

68. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
• Cross-platform formats
–JPEG, GIF, and PNG – Most commonly used
format on the Web
–Adobe PDF (Portable Document Format) –
Manages multimedia content
–PSD, AI, CDR, DXF – Proprietary formats used by
applications
–Initial Graphics Exchange Standard (IGS or IGES)
–Standard for transferring CAD drawings
Image File Types Used
in Multimedia (continued)

69. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Summary
•The computer generates still images as
bitmaps and vector-drawn images.
•Images can be incorporated in multimedia
using clip art or bitmap software, or by
capturing, editing, or scanning images.
•Creating 3-D images involves modeling,
extruding, lathing, shading, and rendering.
•Color is one of the most vital components of
multimedia.

70. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Chapter 4: Sound

71. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Overview
•Introduction to sound
•Digital audio
•MIDI audio
•MIDI versus digital audio
•Recording and editing digital audio
•Audio file formats
•Adding sound to multimedia projects

72. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Introduction to Sound
•Vibrations in the air create waves of
pressure that are perceived as sound.
•Sound waves vary in sound pressure level
(amplitude) and in frequency or pitch.
•“Acoustics” is the branch of physics that
studies sound.
•Sound pressure levels (loudness or volume)
are measured in decibels (dB).

73. © 2011 The McGraw-Hill Companies, Inc. All rights reserved

74. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Digital Audio
•Digital audio data is the actual
representation of sound, stored in the form
of samples.
•Samples represent the amplitude (or
loudness) of sound at a discrete point in
time.
•The quality of digital recording depends on
the sampling rate (or frequency), that is, the
number of samples taken per second.

75. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Digital Audio (continued)
•The three sampling frequencies most often
used in multimedia are CD-quality 44.1 kHz,
22.05 kHz, and 11.025 kHz.
•The number of bits used to describe the
amplitude of a sound wave when sampled
determines the sample size.

76. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Digital audio is device independent.
•The value of each sample is rounded off to
the nearest integer (quantization).
Digital Audio (continued)

77. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Crucial aspects of preparing
digital audio files are:
–Balancing the need for sound
quality against available RAM
and hard disk resources
–Setting appropriate recording
levels to get a high-quality
and clean recording
Digital Audio (continued)

78. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Once a recording has been completed,
it almost always needs to be edited.
•Basic sound editing operations include
trimming, splicing and assembly, volume
adjustments, and working on multiple tracks.
Digital Audio (continued)

79. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Audio resolution determines the accuracy
with which sound can be digitized.
•Size of a monophonic digital recording =
sampling rate x (bit resolution/8) x 1.
•Size of stereo recording = sampling rate x
duration of recording in seconds x (bit
resolution/8) x 2.
Digital Audio (continued)

80. © 2011 The McGraw-Hill Companies, Inc. All rights reserved

81. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
MIDI Audio
•Since they are small, MIDI files embedded in
web pages load and play promptly.
•The length of a MIDI file can be changed
without affecting the pitch of the music or
degrading audio quality.
•Working with MIDI requires knowledge of
music theory.

82. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
MIDI Audio (continued)

83. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•MIDI is a shorthand representation of music
stored in numeric form.
•It is not digitized sound.
•A sequencer software and sound synthesizer
is required in order to create MIDI scores.
•MIDI is device dependent.
MIDI Audio (continued)

84. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
MIDI Versus Digital Audio
•MIDI is analogous to structured or vector
graphics, while digitized audio is analogous
to bitmapped images.
•MIDI is device dependent, while digitized
audio is device independent.
•MIDI files are much smaller than
digitized audio.
•MIDI files sound better than digital audio
files when played on a high-quality
MIDI device.

85. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•With MIDI, it is difficult to play back spoken
dialog, while digitized audio can do so with
ease.
•MIDI does not have consistent playback
quality, while digital audio provides
consistent playback quality.
•One requires knowledge of music theory in
order to run MIDI, while digital audio does
not have this requirement.
MIDI Versus Digital Audio
(continued)

86. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Recording and Editing Digital Audio
•System sounds are assigned to various
system events such as startup and
warnings, among others.
•Macintosh provides several system sound
options such as glass, indigo, laugh.
•In Windows, available system sounds
include start.wav, chimes.wav, and
chord.wav.
•Multimedia sound is either digitally recorded
audio or MIDI (Musical Instrumental Digital
Interface) music.

87. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Audio File Formats
•A sound file’s format is a recognized
methodology for organizing data bits of
digitized sound into a data file.
•On the Macintosh, digitized sounds may be
stored as data files, resources, or
applications such as AIFF or AIFC.
•In Windows, digitized sounds are usually
stored as WAV files.

88. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Audio File Formats (continued)
•The CD-ROM/XA (Extended Architecture)
format enables several recording sessions to
be placed on a single CD-R (recordable)
disc.
•Linear Pulse Code Modulation is used for
Red Book Audio data files on consumer-
grade music CDs.

89. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•MP3 compression is a space saver.
•MP4 is used when audio and video are
streamed together.
•ACC (Advanced Audio Coding) is used by
Apple’s iTunes store.
Audio File Formats (continued)

90. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Adding Sound to Multimedia Project
•File formats compatible with multimedia
authoring software being used, along with
delivery mediums, must be determined.
•Sound playback capabilities offered by end
users’ systems must be studied.

91. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Adding Sound to Multimedia Project
(continued)
•The type of sound, whether background
music, special sound effects, or spoken
dialog, must be decided.
•Digital audio or MIDI data should be
selected on the basis of the location and
time of use.

92. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Create or purchase source material.
•Edit the sounds to fit your project.
•Test the sounds to be sure they are timed
properly with your project.
Adding Sound to Multimedia Project
(continued)

93. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Professional sound
–Compression techniques reduce space, but
reliability suffers.
–Space can be conserved by downsampling or
reducing the number of sample slices taken per
second.
–File size of digital recording (in bytes) =
sampling rate x duration of recording (in secs) x
(bit resolution/8) x number of tracks.
Adding Sound to Multimedia Project
(continued)

94. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Adding Sound to Multimedia Project
(continued)
•Recording on inexpensive media rather than
directly to disk prevents the hard disk from
being overloaded with unnecessary data.
•The project’s equipment and standards must
be in accordance with the requirements.
•It is vital to maintain a high-quality
database that stores the original sound
material.

95. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Keeping track of your sounds
–Audio CDs
•The Red Book (or ISO 10149) standard is a standard
for digitally encoding high-quality stereo.
•For this standard, the digital audio sample size is
16 bits and the sampling rate is 44.1 KHz.
•The amount of digital sound information required
for high-quality sound takes up a great deal of disk
storage space.
–Sound for your mobile
–Sound for the Internet
Adding Sound to Multimedia Project
(continued)

96. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•Sound and image synchronization must be
tested at regular intervals.
•The speed at which most animations and
computer-based videos play depends on the
user’s CPU.
Adding Sound to Multimedia Project
(continued)

97. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
•The sound’s RAM requirements as well as
the user’s playback setup must be
evaluated.
•Copyrighted material should not be recorded
or used without securing appropriate rights
from the owner or publisher.
Adding Sound to Multimedia Project
(continued)

98. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Summary
•Vibrations in the air create waves of
pressure that are perceived as sound.
•Multimedia system sound is digitally
recorded audio or MIDI (Musical
Instrumental Digital Interface) music.
•Digital audio data is the actual
representation of a sound, stored in the
form of samples.

99. © 2011 The McGraw-Hill Companies, Inc. All rights reserved
Summary (continued)
•MIDI is a shorthand representation of music
stored in numeric form.
•Digital audio provides consistent playback
quality.
•MIDI files are much smaller than digitized
audio.
•MIDI files sound better than digital audio
files when played on a high-quality MIDI
device.