PBS 45 & 49 and Inventure Place present the Webcast!
By Ria Mastromatteo, Educational Technology Consultant
Last month PBS 45 & 49 held its first Webcast. It was fascinating stuff.
So what the heck is a Webcast?
Essentially, a Webcast allows you to send audio or video programming over the Web. It is the Internet counterpart to traditional radio or television broadcasting.
A Webcast operates using streaming video "moving images" that are sent in compressed form over the Internet and displayed as they arrive. A "live feed" sends the video as it is happening. The video can also be prerecorded. With streaming video, a Web user doesn't have to wait while the images are downloaded. Rather the media is sent in a continuous stream and it's played as it arrives. The Web user needs a "player" that uncompresses and allows you to view or hear the message. Major players include RealSystem G2 and Microsoft Windows Media Technologies.
Doing this Webcast was "no easy business." Below is a diagram of the set-up used for the Inventure Place Webcast. There were two cameras directed at the speakers and a DAS (the Ohio network for videoconferencing) set up with Avon High School (which was considered a third camera). All of these sent video and audio wires to a mobile video unit, manned by two engineers outside the room where the talent was located. The mobile unit allows the sender to add text to the video to make transitions between pieces of video and to play pieces between speakers. The signals (video and audio) are then sent to a server in the Master Control area through two wires. This translates the signals and sends them to the Internet.
Besides the camera people, the mobile video techs and the people at Avon High School, a director and a director's assistant were involved. They were responsible for lights, makeup, set design (and I guess they really do things like say "action" and "cut!"). All together there were about 12 people involved in the production.
A laptop showed the real-time Webcast. Interestingly, there was about a one-minute delay between the live broadcast and its "Webcast" on the laptop because the signal had to go to Colorado and then come back.
This Webcast is currently available for viewing at http://www.invent.org/inventor/webcast.html until the end of January. If you get the chance, take a peek at the video. Note the size of the image and the fact that the motion is not "jerky." (It took one-fourth of a T1 line to run.)
I found this really interesting and I enjoyed watching it come together. I wonder how this technology will look in 5 years.
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