Live and On-demand: Streaming Multimedia for the Academic Media Center 
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by Gloria Rohmann 
MC Journal: The Journal of Academic Media Librarianship, v6 #1 , Spring 1998 



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 higher bandwidths. 


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. 


THE PLAYERS

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. 

ZDNET (http://www.zdnet.com/findit/mags.html). 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 Shopper


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. 

PRODUCT REVIEWS

  • Avgerakis, George. Industrial strength streaming video. New Media. September 22, 1997.
    (http://www.newmedia.com/NewMedia/97/12/feature/Streaming_Video.html).
    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 bandwidths. 

  • Heid, Jim. Making waves with streaming audio. Macworld. February 1998. 125-127.
    (http://macworld.zdnet.com/pages/february.98/Column.4140.html).
    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 RealNetworks (http://www.real.com/), 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.
    (http://www.eyemedia.com/backissues/1997/1197/stream/eval9711.htm)
    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.
    (http://www.zdnet.com/pcmag/firstlooks/9802/f980227a.htm)
    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.
    (http://www.zdnet.com/products/content/pcmg/1617/pcmg0028.html). 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 1997.
    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 Hill 1997.
    The Bible of digital audio. How to do it right the first time. 

    FORTHCOMING BOOKS
    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 Press. 1998.
    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. 

    TECHNICAL MANUALS
    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. 1998.
    (http://www.microsoft.com/msdownload/netshow20/03000.htm).
    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.

  • (http://www.microsoft.com/workshop/author/streaming/).
    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. (http://docs.real.com/docs/security.pdf).

  • 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 format). 
    
    

REAL-LIFE EDUCATIONAL APPLICATIONS

  • Study Mandarin Chinese using VOA.
    (http://www.webcom.com/ocrat/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.
    (http://sun2.science.wayne.edu/~bio340/lectures/).
    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, p. A29.
    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 (http://www.music.indiana.edu/variations/) 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.
    (http://www.utexas.edu/world/lecture/).
    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

  • Audionet.
    (http://www.audionet.com/)
    Calling itself The Broadcast Network on the Internet' provides access to live events, radio stations and excerpts from audiobooks in RealAudio and Microsoft NetShow. 

  • RealSites.
    (http://www.real.com/content/index.html).
    One of the biggest collections of live and archived audio and video. 

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Gloria Rohmann, gloria.rohmann@nyu.edu, 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 resources.

     ISSN 1069-6792
      Lori Widzinski, Editor (widz@acsu.buffalo.edu)
      Revised: 07/23/98
      URL: http://wings.buffalo.edu/publications/mcjrnl/v6n1/stream.html