A S t r e a m i n g M e d i a P r i m e r :
W H A T I S S T R E A M I N G M E D I A ?
WHAT IS STREAMING MEDIA?
Streaming media enables real time or on demand access to audio,
video, and multimedia content via the Internet or an intranet.
Streaming media is transmitted by a specialized media server
application, and is processed and played back by a client player
application, as it is received, leaving behind no residual copy of the
content on the receiving device.
JUST WHAT DOES IT MEAN TO STREAM?
The primary characteristics of streaming media
Accessible only by users with
high end workstations, the
Streaming is an emerging technology. You'll fi nd that there are many diverse, and often quite confusing,
fi rst true streaming videos run
defi nitions fl oating around. This primer deals with streaming media only i.e., audio, full motion
over the experimental Mbone
video, and multimedia content as opposed to other applications of streaming technology, such as the
(Multicast Backbone) network.
streaming of real time stock quotes. For our purposes, three primary characteristics combine
to defi ne streaming media, as explained below:
Progressive download technology
allows audiences with standard
1. Streaming media technology enables real time or on demand access to audio, video, and multimedia
personal computers to hear
content via the Internet or an intranet.
audio and view video fi les as
Streaming technology enables the near real time transmission of events recorded in video and/or
they are being downloaded.
audio, as they happen sometimes called Live Live, and commonly known as Webcasting.
Streaming technology also makes it possible to conveniently distribute pre recorded/pre edited media
The fi rst all in one, audio video
on demand. In other words, media that is stored and published on the Web in streaming formats can
players are released.
be made available for access at any time.
2. Streaming media is transmitted by a media server application, and is processed and played back by a
True streaming is introduced to
client player application, as it is received.
the general market.
A client application, known as player, can start playing back streaming media as soon as enough data
The World Wide Web Consortium
has been received without having to wait for the entire fi le to have arrived. As data is transferred,
(W3C) endorses Synchronized
Multimedia Integration Language
it is temporarily stored in a buffer until enough data has accumulated to be properly assembled into
(SMIL), a text based tag markup
the next sequence of the media stream. When streaming technology was fi rst available, the ability to
format for streaming multimedia.
begin playback before the entire fi le had been transferred was a distinct advantage. Now, however,
SMIL frees developers from
pseudo streaming techniques, such as progressive download, allow some other formats to begin to
proprietary formats, enabling
play before fi le download is completed. So, while the ability to begin playback prior to completing fi le
multiple vendors to supply
transfer is a characteristic of streaming, it is not, in and of itself, a differentiating factor.
3. A streamed fi le is received, processed, and played simultaneously and immediately, leaving behind
First implementations of MPEG 4,
no residual copy of the content on the receiving device.
an open standard that should
An important advantage of streaming media (unlike either traditional or progressive download)
lead to player interoperability.
technology is the copyright protection it provides. No copy of the content is left on the receiving
device. Therefore, the recipient can neither alter nor redistribute the content in an unauthorized
Streaming marries something old with something new
If you take away the references to the Internet and the computer from our defi nition of streaming media,
it's clear to see that we have been streaming media, according to industry expert Steven M. Blumenfeld,
since the dawn of the media age Streaming media is not new, it has been around since the
inception of the radio (Guglielmo Marconi 1897 inventor of the radio). We just called it broadcast.
Broadcast, however, as we currently know it in the form of radio and television, does not yet provide the
rich media experience that the Internet and the World Wide Web enable.
2 http://broadcastengineering.com/html/2000/august/features/streamMedia_0800.htm, Streaming Media, by Steven M. Blumenfeld, Broadcast Engineering, August 2000