When building media content for network distribution, it's important to tailor content to fit the needs of your users. If your target audience has robust connections and plenty of processing power (i.e., newer and more powerful computers), the use of compression may not be important. In contrast, if the target audience has low bandwidth access and limited processing power, heavily compressed information may be more appropriate.

What are the needs and expectations of the audience? Is the moving image essential for the message, or will an audio clip be sufficient?

One of the advantages of digital information is the ability to compress data. In most cases this compression comes at the expense of quality. We are seeing increasing consolidation of standards as rival media companies move to support each others formats, but ultimately your choice of a compression format will restrict viewers in certain ways. Does your audience operate in a primarily PC-based environment such as we currently have at UNC, or do they use Macs? Do they prefer RealPlayer, or WindowsMedia player? Will this video be part of a larger web-based environment that might entail the use of Flash? Given how much time is involved in encoding media and how difficult it can be (if not impossible) to convert streaming media clips to other formats, it is best to address questions about compression format at the outset of a project.

All of the methods of reducing the file size of media files come at a price. The reduction of frame rates, the reduction of image size, and the addition of heavy compression can make a video clip a blurry mess. Somewhere there is a level of compromise that must be reached. Without any compression the audience for the files may be so limited it loses its value. In contrast, a file with extreme compression may not be clear enough to convey its message.

The amount of bandwidth available for a target audience is one of the biggest factors in deciding on the makeup of content. Bandwidth limitations can eliminate a vast part of the potential audience if content is not created carefully. Media meant for wide area distribution over the web will face bandwidth limitations that won't be present on an intranet. Content intended for end users with modem speed connections must be reduced in quality so much that it could be useless for the intended purpose.

Designers looking to provide smooth video in a streaming format have a good variety of options when delivering content over an intranet with plenty of available bandwidth and robust machines for playback. When trying to deliver the same content over networks with limited bandwidth and devices with limited resolution and processing capabilities (such as hand-held devices), the limitations make the job very difficult. The best chance at success would be a very small video window with significant compression. The good news is that some streaming solutions have come up with smart compression schemes that can produce relatively good quality audio for connections of 28.8 Kbps. They even support stereo audio at these speeds.

One of the biggest problems with bandwidth is that the level of available bandwidth changes with network traffic. A file that streams nicely across the country late at night may not be so smooth mid-morning. A common practice for combating these limitations is to create a variety of clips at different quality and compression levels. This way the clients with high bandwidth connections can go for the quality while the bandwidth-challenged can choose a more compressed version.