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Video StreamingVideo Streaming
Herbert Tuttle,The University of KansasIntroduction 554
Background 554
Networking Concepts 555
How Streaming Works 555
Streaming Technologies and Systems 555
Capturing and Digitizing Video 556
Editing the Video 556
Bandwidth 557
Scaling 558
Compressing and Encoding 558
Video Compression Algorithms 559
Audio Compression Algorithms 560Delivering the Video 560
Receiving, Decoding, and Playing the Video 561
Producing Streaming Video 562
Video Streaming Uses 562
The Big Three Streaming Technologies 563
Other Streaming Video Systems 564
Developments and Trends 564
Conclusion 565
Glossary 565
Cross References 566
References 566INTRODUCTION
It is difficult to describe and predict the growth of video
streaming technology and applications. One may liken it
to predicting the growth and integration of television in
the early 1940s. For the sake of simplicity, a parallel will be
drawn between television and video streaming technology
and applications.
Streaming video, a relatively new technology, has made
it easier for videos to be delivered in a digital format
over computer networks, including the Internet and cor-
porate networks, directly to personal computers. Stream-
ing video involves taking video files, breaking them into
smaller pieces, and sending them to their destination
(RealNetworks, 2000). With a special application designed
to handle video streams at the destination, users can play
the video files as they are delivered or downloaded, instead
of having to wait until the complete video is downloaded
before they can play it. This eliminates the issues associ-
ated with having to download the entire video, including
long wait times and disk space concerns.
Streaming video has given Internet Web site develop-
ers and administrators two primary options for present-
ing videos to their audiences. The first option is “video
on demand,” where the user can access the Web site and
play the video at any time. Typically, the source material
for video on demand is prerecorded and stored material.
Most streaming applications on the Web use prerecorded
material. The second option is “webcasting,” where videos
of specific live events are shown to many viewers at prede-
termined times. Webcasts are usually shown in real time;
there is no prerecorded material. These events can include
corporate meetings, news programs, concerts, and sport-
ing events. These options make streaming video very at-
tractive to viewers. With video on demand, a single video
file can be accessed by hundreds of users. Webcasts are
less expensive than satellite broadcasting, but they do re-
quire technical expertise to set up and deliver (DoIt &
WISC, 2002).
Streaming video’s utility is not limited to educational or
commercial uses. With streaming video anyone can share
his or her creation with others, such as an art work or ashort film. Streaming video takes the everyday “cyberchat”
to a more interactive level.
All indications are that the use of streaming video
will continue to grow. The emergence of DSL- and
cable-connected homes has provided a means to deliver
near-broadcast-quality video to viewers (Microsoft.com,
2001a). Consumers want access to media throughout their
homes and during their daily routines, such as while ex-
ercising or running errands. Companies are discovering
the benefits of utilizing streaming video for training, “vir-
tual” company meetings, and general communications.
E-commerce businesses have found that streaming video
can be another potential revenue source, with “pay per
download” stream applications (Microsoft.com, 2001b).
Artists have new audiences for their craft.
The streaming video technology is still evolving and
has presented many opportunities and challenges to both
developers and users.BACKGROUND
The streaming video technology has been shaped by other
previous major technological innovations such as televi-
sion, movies, videos, personal computers, and modems.
Other significant events that have impacted the develop-
ment and use of streaming video are increased personal
computer ownership, the development and fast-growing
use of the Internet, and nationwide broadband deploy-
ment (Tanaka, 2000).
Of the technological innovations mentioned above,
television has laid much of the groundwork upon which
video and streaming video technologies are based. Many
people were involved in the invention of television and it
developed over several decades. The first television sets
were actually mechanical in nature. However, the devel-
opment of the cathode ray tube and amplifier tube pro-
vided the starting point for electronic television (Fortner,
2002). In 1923, Vladimir Kosma Zworykin, known as
the father of modern television, invented the iconoscope.
(Inventors Online Museum, 2002). The iconoscope
allowed pictures to be electronically broken down into
hundreds of thousands of elements. In 1932, Zworkin was554