A QUIET WEB
Until the emergence of streaming technology in 1995, the Web was a pretty
quiet place. For audio to be delivered over the Internet it must be converted
from analog to digital form. But high-quality digital files are large,
and take time to download, particularly at low modem speeds. Until recently,
compression techniques did not deliver satisfactory results--and files
had to be completely downloaded before they could be played. So while digitized
audio files were available on the Internet for many years, there was no
practical way to use Web-delivered digital audio in anything resembling
the real time instructional environment of multimedia CD-ROM, videotape,
audio tape, radio or television.
HOW STREAMING WORKS
Streaming audio formats, such as those used by RealNetworks, Microsoft's
NetShow and Macromedia's Shockwave audio employ encoding techniques and
players that allow the listener to play the audio (and video) while simultaneously
downloading it. Using a process called buffering, the player downloads
into the memory of the listener's computer a small portion of the sound
before beginning playback. As the audio plays, the player continues to
put some of the file in memory. If the file has been correctly encoded
for the size of the listener's connection and network traffic does not
interrupt the stream, the listener experiences a smooth, broadcast quality
transmission. Most streaming audio files do not require that special software
be loaded on the host Web server. To serve archived audio to more than
one listener at a time, or to stream real-time events, specialized server
software is required.
HOW DOES IT SOUND?
Today's streaming audio encoders use lossy compression techniques to lower
file sizes, as does the jpeg image format. Compression is achieved by dropping
certain digital information from the sound file. Because our ears are unable
to perceive the loss of certain sounds, we hear the sound as higher quality
than it actually is. Files may be encoded at different rates for optimal
playback at different connections speeds: speech has lower requirements
in kilobits per second (kbps) for fidelity than music, for example. Most
streaming video, which requires higher frames per second (fps) and kbps
rates than modems can deliver, is currently only practical at ISDN and
BENEFITS FOR ACADEMIC MEDIA CENTERS?
Using low-cost software tools, free multimedia plug-ins and helper applications,
low-cost storage, moderately priced desktop hardware and servers, and rapidly
improving campus data infrastructures, many academic media centers are
in an good position to take advantage of the new streaming technologies.
Streaming audio can be used in the language lab, for electronic delivery
of audio reserves, for storage and delivery of classroom lectures, to webcast
campus events, and to provide access to audio materials in archives and
special collections. This bibliography provides some of the latest information
on the streaming technologies: how they work, what are the best tools for
authoring and delivering them, and how to stay abreast of new developments.
Anyone following this topic will have noticed how rapidly the technology
is changing and how quickly the industry is consolidating. Three companies,
Microsoft, RealNetworks (formerly Progressive Networks) and Macromedia
have emerged as industry leaders. A standard called ASF (Advanced Streaming
Format) will probably make it possible to encode files that will be playable
on systems from different vendors. But that hasn't happened yet. There
are still at least eight companies with somewhat different solutions to
delivering streaming media-and different, incompatible players. Which ones
to choose? Academic media managers should look in consumer and trade journals
and on commercial web sites. Corporate Intranets are adopting these technologies
for delivery training and company information. Much of this information
is also applicable to the development of media servers and services.
Use this great free resource to search and read full text articles in these
consumer and trade computer magazines: Smart Reseller, Computer Life,
Windows, Macweek, Macworld, Interactive Week, Family PC, PC Computing,
Yahoo Internet Life, Technology Training, PC Magazine, PC Week, Computer
VENDOR WEB SITES
The latest product information can be found here, along with useful technical
information, and tips for content authors. Check out their site galleries
to see which companies and organizations are using which products.
Avgerakis, George. Industrial strength streaming video. New Media.
September 22, 1997.
One problem with streaming video is the proliferation of incompatible
platforms. Up to seven different applications and plug-ins might have to
be installed to view all the formats in use on the web. Microsoft and Real
Networks are attempting to control the market by acquiring interest in
several companies. Products reviewed Microsoft NetShow 2.0b2; Motorola
TrueStream 1.1; Progressive Networks (now RealNetworks) RealVideo 4.0;
VDOnet's VDOLive; Vivo's VivoActive 2.0 (now owned by Microsoft) Vosaic
MediaServer 1.05; VXtreme's Web Theater 2.2 (now owned by RealNetworks).
Rates RealVideo the highest in providing good quality compression at lower
Heid, Jim. Making waves with streaming audio. Macworld. February
Discusses two of the most popular streaming audio formats available,
with emphasis on RealAudio from RealNetworks, Shockwave Audio from Macromedia.
Describes how RealNetworks products have evolved into a complete broadcasting
platform. Shockwave Audio, still an adjunct to Macromedia's program Director,
is less versatile, but Shockwave Audio can be added to web pages without
using Director. Illustrations show how streaming audio works over the web.
Jasco, Peter. Prick up your ears and listen. Information Today.
15:1, (Jan. 1998) 26-27.
Audio compression technology has improved so much (by late 1997) that
near-CD-quality music can be delivered to users with 28.8 kbps modems.
The best compressed music is being delivered in two new formats: MP3, and
LiquidAudio. RealNetworks has emerged as the winner among the original
competitors (StreamWorks, TrueSpeech, etc). Reviews RealPlayer 5.0 from
MP3 (layer 3 of MPEG-1 and MPEG-2 video standards). Samples of streaming
MP3 at http://www.audioactive.com/.
Also reviews LiquidAudio (http://www.liquidaudio.com/),
calling it the best quality audio on the web.
Manners, Chris. Battle of the bands: the sound of streaming. Interactivity.
November 1997. 15-20.
Product Review. Five streaming audio technologies are evaluated: RealAudio,
Shockwave, Liquid Audio, GEO Emblaze Audio and VOSIAC Radio Studio. At
high modem speeds, the audio quality of RealAudio, Shockwave and Liquid
Audio are roughly comparable. Bugs still exist in free encoders and players
from RealAudio and Shockwave. GEO Emblaze Audio and VOSIAC Radio Studio
use Java to stream to Java-enabled browsers (requiring no special plug-ins).
While they produce admirably small file sizes, audio quality is poor. Classic
web audio formats, such as MIDI, may be preferable for certain applications
(background, atmosphere). The MPEG-2 (non-streaming) format provides high-quality
sound, but files are large and must be downloaded completely before listening.
Since nearly every streaming system uses the same data compression techniques
as MPEG, listeners with fast network connections and up-to-date browsers
will get much the same quality from the streaming formats. No consensus
about which streaming format to use has yet been reached.
Ozer, Jan. Real Tools. PC Magazine Online. February 27, 1998.
PC Magazine's First Looks feature finds RealNetworks at the top of
its game with new publishing tool RealPublisher 5.1 ($49.95 list), which
automates encoding, HTML creation, and FTP uploading. Also available from
RealNetworks are plugins for Microsoft PowerPoint 97 and Adobe Premiere
to automate publishing from those programs while creating new mediums for
RealNetworks' technology. Combined, the new tools make RealMedia both easier
to use and more useful.
________. Streaming video: a welcome reception. PC Magazine.
October 7, 1997.
While streaming video quality is not yet acceptable at modem speeds, it
has reached true usability at bandwidths well within the capacity of many
academic networks. Eight streaming video technologies are evaluated for
use on networks at 64 and 128 kbps.
HOW TO USE THE STREAMING MEDIA
Ozer, Jan. Publishing digital video. 2nd Ed. New York. AP Professional
Chapters 4 and 5 of this excellent overview for the non-specialist
discuss the streaming technologies. Of particular interest are the chapters
on codecs and video compression techniques.
Pohlmann, Ken. Principles of digital audio. 3rd Ed. New York, McGraw
The Bible of digital audio. How to do it right the first time.
Publishers have announced these books for spring 1998. Look for them
in a bookstore or at Amazon.com.
Alvear, Jose. Web Developer.Com guide to streaming multimedia. New
York. John Wiley & Sons. 1998.
How to add streaming multimedia to web sites to enhance interactivity.
Contents include: The Basics of Multimedia on the Internet; The Client
Side: Introducing the Programs; Desktop Video: Capturing and Editing Computer
Video; LiquidAudio: Music Publishing and Commerce; TrueSpeech: Streaming
Speech; VivoActive: the Easiest Way to Stream; VDOLive: Live and on Demand
Video (now owned by RealNetworks); NetShow; Stream Works: MPEG Video; GTS
and Emblaze: No-client Multimedia; IP Multicasting over Intranets; Streaming
VRML and 3-D; Streaming E-mail; Streaming and Almost-Streaming Animation;
The Future of Streaming Multimedia. The CD-ROM includes demo copies of
RealPlayer and other popular multimedia programs (many of these will probably
be outdated by the time the book is available in stores).
Melcher, Ryan. The IUMA guide to creating audio on the web. Peachpit
From publisher's description: gives readers everything they need to
know to add sound to their own Web pages: file formats, techniques for
converting files, and advice for optimizing files for the best Web performance.
The CD-ROM includes the audio utilities featured in the book, time-saving
customized scripts for batch conversions, demo sound clips, and much more.
IUMA (Internet Underground Music Archive, http://www.iuma.com)
is a great web site. This book should be worth looking at.
The best guides to streaming media are the ones published by RealNetworks
and Microsoft (NetShow) on their web sites. Here are a few worth downloading:
Microsoft. The Microsoft NetShow 2.0 Content Creation Authoring Guide.
A comprehensive guide to creating stored NetShow content, Compressed
file is 7.6MB. Run ccag.exe to extract the documentation files; guide is
available in both Word .doc and HTML format. Information on the basics
of working with multimedia for beginners, and detailed how-to and technical
information for creating NetShow content. Sample ASF (advanced streaming
format) files are included, and information on how to maximize audio and
video by selecting codecs that are appropriate for content.
________. Site builder network streaming media. 1998.
Streaming Media section of the Microsoft Site Builder Network Workshop.
Technical information for creating content for, and successfully testing
and deploying, Microsoft NetShow. Tips on authoring, including how to convert
existing analog and digital files to ASF (advanced streaming format) and
NetShow, how to set up NetShow server, how to webcast live events, including
streaming from a live TV or radio feed. Information about third-party editing
and authoring software.
RealNetworks. RealSystem 5.0 security features whitepaper. 1998.
A good introduction for web server administrators to the special security
considerations of a media server. Of particular interest to those serving
copyrighted and licensed content to authorized users.
RealNetworks. RealAudio content creation tools. 1998. (http://service.real.com/help/library/encoders.html).
A whole library of content creation guides and technical manuals for
getting the best results streaming audio and video, running media servers,
improving sound and video quality. Covers the all the players, encoders,
servers and the low-cost Real Publisher. Some files in pdf (portable document
REAL-LIFE EDUCATIONAL APPLICATIONS
Study Mandarin Chinese using VOA.
An ingenious use of the Voice of America daily newscasts to assist
in the teaching a learning of intermediate-level Mandarin Chinese. This
Taiwanese web site allows students to listen to sound clips (available
in RealAudio on the VOA web site) from recent VOA newscasts while viewing
the corresponding Chinese characters, pinyin pronunciations, and vocabulary
lists with word definitions. Updated weekly.
Stephenson, Robert. Principles of Physiology.
This high-tech course web site features complete lectures in RealVideo.
Because the instructor doesn't move around too much, they even look good
at 28.8 modem speed.
Wanat, Thomas. Indiana program strives to digitize music without sacrificing the quality
of sound. The Chronicle of Higher Education. May 2, 1997. 43:24,
The Variations Project at Indiana University's Music Library. Concerned
that students at one of the nation's top-rated music schools get the highest
quality sound reproduction from networked-based audio, Variations Project
developer David Fenske worked with IBM to develop a proprietary streaming
solution. While this project does not use commercially available streaming
software, it does provide a model for such delivery using today's higher
quality commercial products.
World lecture hall.
Links to pages created by faculty worldwide who are using the Web to
deliver class materials. For example, you will find course syllabi, assignments,
lecture notes, exams, class calendars, multimedia textbooks.
STREAMING AUDIO AND VIDEO CONTENT RESOURCES
Calling itself The Broadcast Network on the Internet' provides access
to live events, radio stations and excerpts from audiobooks in RealAudio
and Microsoft NetShow.
One of the biggest collections of live and archived audio and video.
Gloria Rohmann, email@example.com,
is Head of Media and Electronic Resources at NYU's Bobst Library. In cooperation
with NYU's TV and Media Services Department, she facilitates webcasts of
campus events using RealAudio server software. Live coverage of NYU's Annual
Commencement will be available via RealVideo on May 14, 1998. URL: http://www.nyu.edu/library/nyutv/.
As an extension of the Language Lab and Media Center reserves services,
she is also developing extensive RealAudio archives for fall 1998.
Copyright 1998 Gloria Rohmann. All rights reserved. Commercial use requires
permission of the author and the editor of this journal.
The author and editors do not maintain links to World Wide Web
Lori Widzinski, Editor (firstname.lastname@example.org)