Streaming Media Overview:
A look at the current
technology and what CIT is doing with it
In July/August1998 I wrote an article for the CIT
Information newsletter describing our use of streaming
audio and video. At that point we had been using some form of streaming
media for about two years. Since 1998 the technology and its applications
at CIT have changed and matured, and our use of the technology has
diversified. In the following paragraphs I will try to describe
some of the ways CIT is using streaming media and highlight some
of the technological advances made during this time period.
An overview of the technology
Streaming, in simplest terms, is a process allowing a file to be opened
before the entire file has been transferred or copied from the media
server to the local hard drive. Typically what happens is that a request
for an audio or video file is made from a client’s browser via
a Web page. After the client’s browser receives the file information,
it launches the streaming application or plug-in to receive and play
the audio or video stream.
This definition has not changed. What has changed is the number of
companies offering streaming product solutions, the number of formats
that offer streaming solutions, the amount of content available online
and, perhaps more importantly, the number of potential users of streaming
media. Of these factors the number of potential users who have some
form of broadband connection is, in my opinion, the driving force behind
the growth of this industry, along with the fact that the average desktop
computer today has more than enough processing power and high enough
quality video hardware to handle receiving audio and video streams.
In 1998 this was not always the case.
In 1998 the number of companies offering streaming media solutions
could be counted on one hand. Today I could not even begin to list the
companies offering some sort of streaming media solution. Nearly every
major news corporation offers news, entertainment clips, and live feeds
in one or more streaming format and almost always at a low and high
bit-rate.
A good example of what has happened in the industry in the past five
years is the growth that RealNetworks has reported.
In 1998 I reported that “The current market leader (Real Media)
announced their streaming video product in March of 1997. Within a month
8 million users had downloaded the Real Media browser/plug-in. Roughly
one year later 44 million users had downloaded this product.”
Looking at their website today, RealNetworks reports that:
- “RealNetworks technology is used by hundreds of millions of
unique, registered individuals throughout the world.
- RealOne Player user base grows over a hundred thousand new users
per day.
- RealPlayer/RealOne Player is the second most widely-used Internet-based
software application in the world.
- RealNetworks system software delivers content on more than 85% of
all streaming media-enabled Web pages.
- RealNetworks system architecture is used to broadcast more than
350,000 hours of live sports, music, news, and entertainment over
the Internet
every week. Hundreds of thousands of hours of on-demand content
are also available.”
(RealNetworks Website, Company information: Just the Facts. October
27, 2003. www.realnetworks.com/company/index.html)
As you can see, streaming technology has become a mainstream Internet
application, and continues to grow.
IANR’s use of streaming media
In 1998, I described IANR’s use of streaming media. We had some
successes and failures and determined that part of the success equation
depended on how an instructor was implementing the technology. Some
instructors were very capable of working in the convergence of live
television and online technologies and some found this difficult. The
same could have been said about the individuals producing the content.
As the technology matured, and as faculty, staff, and students were
exposed to the technology, some of these barriers have been lowered.
Currently, CIT does not stream classes “live,” but does
encode a lot of supplemental and prerecorded content for use in many
classes. A lot of content is reused from previous classes in this manner.
CIT does however encode live programs. Currently Backyard Farmer, Market
Journal and several video conferences annually are “broadcast” live
on the internet. Backyard Farmer (byf.unl.edu) is a good example
of how CIT uses the streaming technology. You can watch the program
live, watch a previous program from the archives, or search the program
archives by keywords. This last feature is what I find most exciting.
For example if I search for “pruning,” I get a list of links
to video segments of Backyard Farmer where the topic was pruning. These
links take me to the portion of the program(s) where the topic is discussed,
so I don’t have to watch or fast forward through a program or
programs to find my answer, which is a great time-saver. The Backyard
Farmer site also lists the top twenty most viewed clips, which is helpful
when there are global gardening issues.
The technologies behind the site primarily integrate an SQL database,
Apache Webserver, and RealNetwork technologies. The Backyard Farmer
site demonstrates some of the advantages to using online audio and video
content over the traditional linear distribution of these programs.
(As I wrote the article in 1998, these technologies were just coming
online and we were not sure how we were going to implement and integrate
these technologies into our application development. We have barely
scratched the surface, and the Backyard Farmer site is one of the best
examples of our development.)
IANR and CIT have also been involved with the American Distance Education
Consortium (ADEC), working with using streaming media over a satellite
based network. While working with the multicast protocol, this project
uses Apple’s Darwin Streaming Server technologies, the h.323 protocol,
and MPEG-4. ADEC is partnering with Tachyon.net (IP-over-satellite service
provider) on this project.
Some of the barriers in a satellite network include the fact that bandwidth
is limited, net traffic is asymetric, and atmospheric conditions can
come into play. Advantages of working with the ADEC satellite network
include
- the fact that it is a multicast-enabled network,
- that we can get broadband services to locations where even cell
phone connectivity is a problem, and
- that it is a network where ADEC is able to control network hardware
to a degree to do testing.
The multicast protocol in simplest terms is a protocol which allows
many network devices to listen to a single stream of data (and/or audio
and video) as opposed to unicast, where each device receives it’s
own individual stream. This is very significant in limited bandwidth
networks, and all networks ultimately are limited. Many routers are
not configured to allow multicast traffic to pass and the stream fails.
One example of this work was the April 2, 2003 ADEC video-conference.
This program, and several that we have hosted since April 2, was an
example of successful use of the multicast protocol, the MPEG-4 audio/video
format, and Apple’s Darwin Streaming Server technology. (See
schematic drawing.)
This program had several pieces which all had to work together. One
part was getting h.323 feeds into CIT’s television studio from
six colleges and universities. Another part was encoding the video from
the studio into the MPEG-4 format and the Real Media format. Another
piece was sending a unicast stream via Internet2 (I2) to a Darwin Streaming
Server in San Diego, (The server was on both I2 and on the ADEC satellite
network). The unicast stream was then relayed as a multicast stream
to the ADEC satellite network. ADEC also broadcast this conference via
traditional C-band satellite, a unicast Real Media stream (for ADEC
personnel not on the satellite network), and an audio phone bridge.
Implications and conclusion
Streaming media technologies open many doors and solve a lot of problems
facing distance learning instructors, content providers, instructional
designers, and students. Users can time-shift programs and classes to
fit their schedule in their location, and can review materials and presentations
several times.
Providers can overcome cost factors, satellite footprints, and political
and geographical borders, delivering their classes and programs to new
student bodies and clientele. And, instructors and designers can develop
robust presentations that they may not be able to present in the traditional
classroom.
Distance learning environments can and will become better learning
tools as the
- convergence between print, data, audio, and video continues;
- CPU’s become more powerful; and
- bandwidth increases.
Seven years ago I used the analogy that streaming technologies were
in the “Kitty Hawk” phase of development, and five years
ago I rephrased and stated that perhaps the technology had reached the “Spirit
of St. Louis” phase — now I’d say we have entered
the DC-3 phase where we have a reliable and affordable set of technologies
to use.
~ Mark Hendricks |
