Primer on Multimedia on the Internet for VSC:
Basics for the Educational Use of Video on the Internet

Robert Gershon
Professor, Communication,
CSC

 

 

Why Use Multimedia?

Video Technologies

Streaming Media
Formats and plug-ins
Format examples
Producing Audio and Video for the Internet

Computer screens now vie with tv sets for the attention of an increasing audience including a large segment of our students.  While this is no particular reason to try to translate the content we use which does so well in print and in person, it does offer the ability to move the viewing of video from a more passive “lean-back” situation viewed in class, to a “lean-forward” experience watched by students under circumstances of their choosing.  Online video, being more or less randomly accessible, also has the potential to be linked from and to a variety of content sources, allowing students to navigate subjects via different paths.  (This is clearly a two-way street; in many situations a student might be best served by being led to a conclusion by a specific logical path.) This potential has not gone unnoticed in the higher ed community; colleges and universities are increasingly adopting Internet media from audio Podcasts to entire courses delivered via streaming video.

 

While the underlying technology of Internet multimedia is complex, the technology to provide multimedia for one’s courses requires little expertise beyond using a video camera and computer.

Why Use Multimedia?

Assuming you are using the Web already (Blackboard, of course, is the leading VSC use of the Web), you are undoubtedly aware of its benefits. In addition to these multimedia on the 'net is valuable in the same ways audio and video have been in more traditional settings: they can show the viewer things that are distant in space and time and too slow or fast or small or large for the eye to see. They can condense the time necessary for various experiences (e.g. interviews with experts), expose many people to master educators and provide repeatability. It's useful to consider why you might use video to make sure the effort you put in will provide something otherwise not available to your students.

 

Video Technologies

 

Technically online video is quite dissimilar to television.  The latter is broadcast at a given time to all within range to a large screen generally viewed from several feet away and viewers choose from among a relatively small number of choices.  One generally watches online video from a couple of feet away.  Most importantly one is usually in contact with a controlling device that can not only pick that item from a number of choices, but find a video from within millions of possibilities and play it at the viewer’s choosing.  The video is almost always smaller than a typical tv image and of lower quality. 

 

The reason for that size and quality is the fact that online video is almost always transmitted through a much smaller bandwidth than television.  A typical Internet video piece will run at 384 thousand bits per second.  Broadcast tv provides (depending on how you convert the analog tv numbers to digital, as used by computers and the Internet) 6 million bits per second.  (There are huge gains made by moving from analog to digital but that’s still 15 times greater and it shows.) 

 

One other difference is that tv is sent to your set on a given channel and needs only to be selected to be played.  Actually what’s happening here is that your tv set is “decoding” the complex parts of the tv signal and putting together picture and sound from them.  The same thing happens in your computer with one big difference.  Broadcast tv operates on one national standard.  (Aside: if you want a political map of the 1950-60’s look at the world by national tv standards.  USA client states of that time run ours; much of Africa and the Middle East use Western Europe’s; and those courted by the USSR use theirs.)  Internet video, on the other hand, uses any of a large number of incompatible standards.  Fortunately most will play on almost all computers, but usually not without a plug-in (e.g. Flash, Quicktime, Real Player, Windows Media).  The most-used of these are often pre-loaded on computers or their Internet browsers, but the need for specific plug-ins denies a distributor the certainty that any given would-be viewer can actually see the video without downloading a plug-in.

 

Streaming Media

 

Online video is often referred to as “streaming,” but often that is not the case technically, and in this case the technicality actually has some use for us and, particularly, for our network administrators.  Much of what we watch on computer is not streaming but “progressive download” video.  Who cares?  Mostly, no one.  From the perspective of the teacher or student the difference is small but it may be useful.  In true streaming video situations viewers can navigate to later portions of the piece with only small delays.  With progressive download (sometimes called “fast start”) the entire video up to the portion to be viewed must be downloaded before viewing.  (That’s often a tough one to concern ourselves with when we want out students to watch the whole thing, no?)  That’s because progressive downloaded video starts at the beginning and downloads until the receiving computer decides there’s enough received already to keep the video running if the later parts of the video continue to download at about the same speed.  (Typically a bar on the viewer window will show how much is downloaded and where one is in the video playback.)  Streaming, on the other hand, responds to a viewer’s command to move to a later part of the stream. In many cases progressive download media can be saved easily on one’s computer which might create copyright concerns.  (Of course, if you go to enough effort all Internet video can be saved locally.)  Because progressive downloads begin with a finished media file on the server, only true streaming can be used for live “webcasts.”[1]

 

Progressive and streaming video differ significantly from the server's perspective. Progressive download video runs on the same Internet protocol as standard web pages, http.  That means they can be posted on standard web servers (though because their size is so much greater than most pages, sometimes available bandwidth can be an issue).  In fact short progressive videos can run well from Blackboard. True streaming media, on the other hand, requires a specialized server usually specific to the streaming format.

 

Formats and plug-ins

 

The development of Internet video has been dominated by various proprietary formats, advanced by specific companies, each vying to become the digital audio/visual standard. Some higher educational institutions have chosen a specific format and set of parameters for their use of video; others support many formats. While there are a plethora of video formats, four major ones dominate the field: Windows Media, Quicktime, Real Media and Flash.  All may use progressive or true streaming delivery. [2]  Here’s a quick rundown of their plusses and minuses:

 

Examples of each of the above

 

Producing Audio and Video for the Internet

 

Producing audio for the ‘net is quite simple and might best be simply posted as progressive download MP3s on Blackboard.[5]  One can record audio using the microphone that comes with many computers.  Many computers also come with audio recording software, and free or inexpensive software is available.  Almost all audio software will output on MP3 (though the best known open-source free software, Audacity requires a “Lame” plug-in, also free and linked from its site).  Quicktime Pro is also a fine tool—less powerful than Audicity but far easier to learn and use--for recording and editing audio.

 

Some simple tips for good recording are actually pretty obvious. 

 

For video production you’ll need a video recorder and some kind of video editing software.  While your picture will end up smaller and jumpier than on tv you still should try to start with the best quality original video; video “noise,” camera movement, poor lighting, etc. are amplified in the process that encodes video for the Internet.  Still, it’s difficult for a viewer to tell the difference between a picture taken by a $60,000 studio camera and a well lit video shot on a $250 DV camera.  While on the one hand new hard drive and DVD consumer video cameras are challenging DV and on the other high definition cameras are replacing DV in the high end of the market, the latter provides no real advantage over DV in typical streaming applications and the former are actually worse,[6] though they still can provide good quality.

 

Tips for shooting video for the Internet:

 

 

 

 

 



[1] An excellent tutorial on streaming media in higher education is available at http://streaming.wisconsin.edu/understand/understand.html.

[2] For a good technical overview of  current leading formats try http://www.streamingmedia.com/r/printerfriendly.asp?id=9259

[3] http://www.adobe.com/products/player_census/flashplayer/

[4] Since unlike Windows and QT, Real is not related to a given computer operating system and has no real built-in revenue source, they try more than the others to sell a tricked out version of their free plug-in, so it’s sometimes hard to fine the free one.  As of this writing is in the upper right quadrant of http://www.real.com/

[5] One such VSC use can be heard at http://com.castleton.edu/touchstones/ .

[6] The reasons for this are beyond the scope of this piece but have to do with the way video is compressed for hard drive and DVD storage and must be uncompressed and then recompressed for the Internet causing compression artifacts in the video.