2. Multi-media
Multi means many
Media: a ways of communication such as text, image,
audio, video, graphics and animation
Multimedia -- a dictionary definition
Any thing that combines more than one media
Multimedia is qualitative rather than quantitative
Multimedia
3. Definition:
It consists of all applications that involve a combined use of
different kinds of media, such as text, audio, video, graphics, and
animation.
Examples:
A presentation that involves all these different media types can
be termed a multimedia presentation. Software that involves
animations, sound, and text is called multimedia software. Also,
any system that incorporates different flavors of media can be
termed as a multimedia system.
Multimedia
4. The word multimedia was coined in the beginning of the 1990s. After
the success of the digital audio recording industry, and the distribution
of digital audio in the form of compact discs (CDs).
The next anticipated step was to create digital content involving images,
text, and video along with audio and distribute it in a similar fashion.
Outcomes of this were multimedia CD-ROMs, which included
informational content as well as games. Examples of these include,
Encyclopedia Britannica and interactive CD-ROM games with simple
graphics, animations, and audio.
These experiences were then only limited to a single person interacting
with the content on a PC computer.
But this single person-to-PC experience changed dramatically with the
advances in digital networks and digital distribution technologies.
Historical Perspective
5. Multimedia world altered the ways of communication
with the
availability of low-cost capture devices, rendering
devices, and smarter software to create content;
Larger, less expensive storage devices along with
research in better compression of media content
Technological advances in digital networks and
standardization of distribution protocols.
Historical Perspective
6. The preceding three points directly map to three processes that
are now inherent to multimedia systems and considered as
components of multimedia:
1) Multimedia content creation or multimedia authoring
2) Storage and compression
3) Distribution
Components of Multimedia
7. Multimedia content creation or multimedia authoring—
This process involves digitizing media (audio, images, video)
using capture devices and assembling/processing them
using smart software and hardware.
Storage and compression—Multimedia content created
today has significant memory requirements and has to be
engineered so as to minimize necessities for storage and
distribution. The process mostly involves state-of-the-art
compression algorithms and standards for audio, video,
images, and graphics.
Components of Multimedia
8. Distribution— Distribution involves how multimedia
content is distributed via various media, such as wired
cables, optical networks, satellite, wireless networks, to
specific platforms ranging from television, computers,
and so on.
Components of Multimedia
10. Multimedia is qualitative, inherent qualities generic to
all media in turn defines the nature of multimedia.
1. Digital— Multimedia information is always digital. In
fact, it is the digital nature of the information that
allows it to be combined together (or to keep its
own identity) to produce rich content. Whether it is
digital images, video, audio, or text, the underlying
representation of the information is always bits and
bytes.
Inherent Qualities of Multimedia Data
11. 2. Voluminous—The size of the data resulting from combining video,
audio, and images together is understandably large and voluminous.
This causes problems when such high volume data has to be stored,
searched, and, worse, when it has to be transmitted over bandwidths,
which might be narrow, wide, and even varying. The storage and
transmission bandwidth limitations require that the data be
compressed.
3. Interactive—Multimedia content can be interacted with from a high-
level application point of view, such as choosing a video to watch or a
set of images to browse down to a low level, where you can click on
areas of an image causing an action to be taken. For example, on a Web
site consisting of hyperlinked text, images, or video, you can read, jump
to different Web sites, or browse video in any order you want. Another
practical example of interactivity is the navigational capability to jump
to chapters as well as browse additional related content in a DVD
experience.
Inherent Qualities of Multimedia Data
12. 4) Real-time and synchronization— When transmitting
content involving different media types, real-time
requirements and resulting synchronization issues play a
crucial role in the system’s architecture and design. Real-
time needs imply that there can be only a very small and
bounded delay while transmitting information to the end
client. Synchronization imposes time-respected rendering
of the media, which might be self-contained or
interdependent. For instance, video has to play at a
certain rate (intramedia) while the accompanying sound
must match the video playback rate (intermedia).
Inherent Qualities of Multimedia Data
13. 1. Text
Text has been commonly used to express information not just
today but from the early days.
The representation and writing of text information has evolved
from simple text to more meaningful and easy-to-read formatted
Text, use a variety of fonts.
Today, hypertext is commonly used in digital documents,
allowing nonlinear access to information.
ASCII (American Standard code for information interchange) is a
well known format used for digital text.
Different Media Types Used Today
14. 2. Images
Images consist of a set of units called pixels organized in the form of
a two dimensional array. The two dimensions specify the width and
height of the images. Images can be characterized as:
Bit depth— number of bits assigned to each pixel.
3. Video
Video is represented as a sequence of images.
Each image in the sequence typically has the same properties of
width, height, and pixel depth.
Apart from this basic definition, video can be classified depending
on the following:
Different Media Types Used Today
15. Aspect ratio —A common aspect ratio for video is 4:3,
which defines the ratio of the width to height. We
have a variety of different aspect ratios for high
definition, cinemascope, and so on.
Scanning format —Scanning helps convert the
frames of video into a one dimensional signal for
broadcast. The interlaced scanning format was
invented to make television work in the middle of the
last century. Today, in the digital world, display
devices can support progressive scanning and provide
better quality for visual information.
Different Media Types Used Today
16. 4. Audio
Digital audio is characterized by a sampling rate in hertz, which
gives the number of samples per second. Apart from these
properties, audio is also described by:
Dimensionality—The dimensions of an audio signal signify the
number of channels that are contained in the signal. These may
be mono (one channel), stereo (two channels). Recent
standards also use surround sound which consists of many
channels.
Frequency Range— Audio signals are also described by the
frequency range or frequency band that they contain. Range of
frequency that a system can process is considered as bandwidth.
Different Media Types Used Today
17. 5) Graphics
a) 2D Graphics
2D graphical elements have become commonplace in
multimedia presentations to enhance the message to be
conveyed. A 2D graphic element is represented by 2D
vector coordinates and normally has properties such as a
fill color, boundary thickness, and so on.
b) 3D Graphics
3D graphics are primarily used today for high-end content in
movies, computer games, and advertising. Like 2D graphics,
3D graphics largely make use of vector coordinate spaces.
Different Media Types Used Today
18. Depending on the application, multimedia systems can be
classified in a variety of ways, such as interaction style, the
number of users interacting, when the content is live, and so
on. A few common classifications are discussed in the
following list:
Static versus dynamic — This differentiation refers to cases
when the multimedia data remains the same within a certain
finite time, for example, one slide of a Microsoft PowerPoint
presentation or one HTML web page. Compare this with the
dynamic case when the data is changing, for example
watching a video.
Classification of Multimedia Systems
19. Real-time versus orchestrated — Orchestrated refers
to cases when there is no real-time requirement. For
example, compressing content on a DVD and
distributing it has no real-time requirement. However,
showing a game in a live broadcast over the Internet
imposes a whole new set of engineering constraints
in addition to compression quality, which relate to on-
time data delivery.
Classification of Multimedia Systems
20. Linear versus nonlinear — Here, the method of
interaction with the multimedia data is used to
differentiate the system. In a linear system, you
would proceed linearly through the information, for
example reading an eBook or watching a video.
However, if you want to interact with the data in a
nonlinear fashion, you would have to make use of
links that map one part of the data to another. A well-
known example of this is hypertext.
Classification of Multimedia Systems
21. Person-to-machine versus person-to-person — In this case, the
classification is based on whether the end user is interacting with a
machine or with another person. For example, playing a CD- ROM
game is a simple person-to-machine experience. However,
videoconferencing is a person-to-person experience.
Single user, peer-to-peer, peer-to-multipeer, and broadcast —Here,
the manner of information distribution is used as a means to
classify a multimedia system. You might have a single-user scenario
such as browsing the Web, or it could be a peer-to-peer scenario
when the information is exchanged from one person/computer to
another, for example two friends instant messaging over the
Internet.
Classification of Multimedia Systems
22. A peer-to-multipeer scenario extends the paradigm to
sending messages to a limited set of intended viewers
such as in a chat room. Broadcasting is the most
general-purpose scenario, where information is sent
not to any specific listener(s) but available to all those
who want to listen, such as television and radio
broadcasts.
Contd.
23. Multimedia systems can be logically grouped into three parts whose
primary functionalities are (1) content production, (2) compression
and storage, and (3) distribution to various end users and platforms.
The multimedia experience today has transcended a simplistic one
person-to-PC scenario to become a very sophisticated one, which
involves a distributed and collaborative medium. This has been made
possible because of sophisticated, inexpensive devices for capturing
and rendering content, as well as smarter software to create
content and the availability of increasing digital bandwidth.
A Multimedia System Today
24. The figure in following slide explains typically end to
end multimedia systems today.
It consist three logical sections which has been
explained earlier.
Content creation
Compression and storage
Distribution
A Multimedia System Today
25.
26. THE MULTIMEDIA REVOLUTION
Revolution of multimedia is multidisciplinary
Two decades ago it is hard to find a wireless phone or
cell phone
Dramatic increase in processing power, high storage
devices, and huge bandwidth availability are the
common reason behind multimedia today.
It is hard to quantify the all reasons but a few are
defined in following slides.
27. Digitization of virtually any and every device —
Today, you have digital cameras, camcorders, sound
recorders that make good-quality digital media
available for processing and exchange. At the same
time, digital displays such as high performance
cathode ray tubes (CRTs), liquid crystal displays,
plasma screens,and so on allow us to view
information at good resolutions.
THE MULTIMEDIA REVOLUTION
28. Digitization of libraries of information — Virtually all
libraries, whether general purpose or specific, are
making their way to be digital.
Evolution of communication and data networks —
The research in digital networks and networking
protocols have made it possible to exchange huge
amounts of data over wired, optical, and wireless
mediums. Deployments in this area are making
availability of bandwidth on demand.
THE MULTIMEDIA REVOLUTION
29. New algorithms for compression — Because multimedia
information is very voluminous, abilities to compress
information prior to sending it over networks allow us to
engineer applications that perform in real time and with a
high fidelity.
Better hardware performance — Microprocessors, along
with graphical processing units (GPU) are both getting
faster and perform better. Also, large capacity storage
devices are becoming common place now, not just with
computers but also other hardware devices such as digital
cameras, camcorders and so on.
THE MULTIMEDIA REVOLUTION
30. Smarter user interface paradigms to view/interact
with multimedia information on a variety of
terminals — As personal communication devices get
compact and smaller in size, the role of user
interfaces becomes important when it is expected for
them to have information access capabilities similar
to a computers. User interface designs based on
touch screens are now playing an increasing role in
how we access information on our cell phones, PDAs
and so on.
THE MULTIMEDIA REVOLUTION
