A Technical View: Streaming Web Video

I first came across the idea of using streaming video technology in the delivery of course materials in the January 1999 Syllabus magazine. In an article in that issue, Lawrence Hinman, a professor of philosophy at the University of San Diego, compared non-streaming and streaming video technologies and described the steps to putting video on the Web. Since then, I’ve learned from my own experiences incorporating streaming Web video in chemistry classes at Ohio Eastern University.

Video files are usually several megabytes in size and consequently take a long time to download. A non-streaming video file has to be downloaded in its entirety before it begins to play. In streaming video technology, the program downloads the beginning of the file, forms a buffer of packets, and when an appropriate buffer is reached, the client player plays back the packets in a seamless stream. While the viewer is watching, the next portion is downloaded, until the entire file is played without any interruption. Streaming media can include audio, video, animation, and scrolling text.

Producing both live and streaming video require the same equipment: a video camera (analog or digital), video capture card, a video editing program, video encoding technology, a computer with plenty of storage to act as a server, and a high-speed network connection.

In a typical chemistry class, it is often difficult to teach students the correct use of an apparatus and safety precautions for handling chemicals and equipment before they perform an experiment. They also need to have a clear understanding of chemical reactions and how to handle them. Some students may be capable of grasping these concepts by reading a printed lab manual, but most students now learn more through visual aids.

At Ohio University Eastern campus, we have tried to incorporate all of these factors in producing video clips of chemistry experiments for students to view before they actually carry out the experiments. And, for the last two years our freshman chemistry students themselves have been involved in the production of video clips of chemistry experiments.

While commercially produced videos of chemistry experiments are available, we believe that students can absorb and relate better to demonstrations they produce themselves. In this case, the students researched the topics and wrote outlines. They also demonstrated the techniques of each experiment and provided the narrative. Then videos that were shot were edited, compressed, and several video clips of each experiment were produced.

We bought a license for RealServer software to stream the videos on to the World Wide Web. The video clips are now available at the course Web site for students to view before they come to the laboratory. Computers are also available in the laboratory for students to review all or parts of the video clips while they do the experiment.

When we decided to investigate streaming audio and video, we examined several formats that were available, including RealNetworks, Windows Streaming, and QuickTime. We settled on the Real format because it has good compression while still maintaining good sound and video quality. Real’s cross-platform capabilities have also been important to us. The Web was designed to be accessible no matter what computer operating system one might be using—Windows, Linux, Macintosh, BeOS, or DOS.

The RealPlayer is available, for free, for most of these operating systems, so we can be reasonably sure that our students will be able to access the audio and video clips even if they use older computer systems. Our campus is located in a rural area and many of our students can’t afford the newest, whiz-bang computers. Also, the Real format can include compression back to RealVideo 5 (they are now at version 8), so that older computers can still view our clips.

Our RealServer is running on a 600Mhz Gateway 7210 server with 512M of RAM, and 2 two hard drives: a 15G drive that contains the operating system files and a 8G SCSI drive for the Real audio and video clips. As additional space is needed to store the audio and video clips, we can add additional drives to the SCSI chain. The server is running RedHat Linux 6.2 as its operating system. We have had very few problems with it. As of now, the Real server has been running continuously for almost three months without requiring a reboot.

We are currently feeding our clips out over a T1 (1.5 Mbs) connection and so far, we haven’t experienced problems with network congestion because of the streaming video. But as more faculty and students start using the RealServer, network congestion will become an issue—and my next challenge.

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