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  1. 1. Live broadcast of Web-based courses using real-time streaming media Thomas I. M. Ho Department of Computer Technology Indiana University Purdue University Indianapolis 723 W. Michigan Street Indianapolis, IN 46202-5132 USA Phone 317 274 6799 Fax 317 274 9702 Abstract Over two years of experience by Thomas I. M. Ho (1998 & 1999) with the application of real-time streaming audio and video (RealAudio/Video) to Web-based courses has yielded a wealth of experience in synchronous delivery of live instructional content and asynchronous delivery of archived content. Future plans for equipping classrooms to originate live broadcast will also be described. What is RealAudio/Video? The RealNetworks Server, RealProducer (previously called RealEncoder), and RealPlayer comprise the RealMedia System created by RealNetworks (1999). The RealNetworks Server streams files created with the RealProducer to free RealPlayers on sound card- equipped personal computers, which continuously decompress the audio and play it in real time without download delays, even over 14.4 Kbps modems. RealAudio has been widely deployed on the World Wide Web especially to distribute news and music as described at the RealGuide (1998) site guide. More recently, RealVideo has added video capability to RealAudio within the RealMedia architecture. Educational applications have become more common and examples can be found at RealNetworks’ (1998) education page. Experiments with RealVideo Beginning in January 1998, Electronic Commerce (CPT 499) broadcast lectures live from Indiana University Purdue University Indianapolis (1998) via RealVideo. Origination of live broadcast and archiving were accomplished via the ClassCast project developed by the WebLab (1997). Figure 1 describes ClassCast’s components for originating live broadcasts. User interface for originating live broadcast The live lecture is broadcast to remote viewers via the ClassCast user interface (Figure 2) with the following capabilities:  Delivery of audio/video content  “Pushing” Web pages displayed to students in the classroom 1
  2. 2.  Chat to enable remote viewers to ask questions and to participate in classroom “discussions” Figure 1. ClassCast environment for live broadcast A notable contribution of the ClassCast user interface for the instructor is its ability to “time-stamp” each mouse click while “pushing” Web pages to remote listeners. This capability has greatly facilitated the creation of event files for producing Synchronized Multimedia versions of the lectures for archived playback! Since the concept has been proved, a number of improvements to the ClassCast environment will be made. The highest priority is ease-of-use for the user interface so that the initiation of the broadcast is synchronized with the “time-stamping” because initiation of a broadcast currently requires two separate actions by the ClassCast operator. This experiment has demonstrated that significant instructional content can be delivered via real-time streaming audio and video that can be received by a modest computing platform with no more than a 28.8 Kbps dial-up connection to the Internet. 2
  3. 3. Figure 2. ClassCast user interface Although a notable outcome is the fact that an ordinary classroom was equipped with the ClassCast originating equipment for only about $20,000; we anticipate that this pricetag can be reduced by creating a portable version of the ClassCast origination equipment by using a laptop computer to accommodate the encoder and by using less expensive audio/ video equipment since encoding at a low bit rate doesn’t require a high-quality video source. This solution would also have the advantage of portability enabling virtually any classroom with an Internet connection (or within the range of a wireless local area network) to originate a broadcast! Another capability developed by the WebLab (1998) is NetCast which enables RealAudio content to be originated (broadcast live and archived) from anywhere via telephone. This capability is convenient for originating lectures from home when the instructor is ill or even for delivering conference presentations at remote locations without traveling to the conference venue. NetCast has the additional capability of scheduling the encoder via the World Wide Web as well as equipping the encoder with “auto answer” rather than requiring human intervention to answer the phone when initially connecting to the encoder. References Ho, Thomas I. M. (1998) Application of real-time streaming audio and video to Web-based courses [WWW document] URL 3
  4. 4. Ho, Thomas I. M. (1999) Experiences with real-time streaming audio/video in delivering Web-based courses [WWW document] URL Indiana University Purdue University Indianapolis (1998). Electronic Commerce (CPT 499), Web site [WWW document]. URL %2D499%2DB554 (log in as guest) RealGuide (1998). Web site [WWW document]. URL RealNetworks (1999). Web site [WWW document]. URL RealNetworks education page (1998). Web site [WWW document]. URL WebLab (1997). ClassCast, [WWW document]. URL WebLab (1998). NetCast, [WWW document]. URL 4