| Multimedia |
The use of multimedia is becoming a major focal point of Web development because the Internet is a natural medium for distributing media-based resources across computing platforms. Creating Web-ready media resources has become simpler as development and conversion tools have evolved.
Although recent Web browser releases have built-in support for media content, many media formats are supported by helper applications. Helper applications display media content external to the browser. A concern with some helper applications is they need to download an entire file before viewing. Media streaming, or real-time media playback, has begun to change this. Software such as RealPlayer and Microsoft's Windows Media allow the user to begin playing files before the are completely downloaded.
These products show great promise in the delivery of multimedia, bandwidth, however, network traffic still can slow transmission rates. The result of a slowed transmission is a jerky, pixelized, "man on the moon" image. The size of video files is also a major concern to developers. It is not uncommon for a 30 second video to be several megabytes in size even after file compression. Downloading a file this size over a modem could take over an hour.
Video
The primary video formats and MIME extensions are MPEG (.mpg), ReadMedia (.ram), and QUICKTIME (.mov).
This is an example of a link to video of a Space Shuttle
Launch. (format: MPG; Size: 800k).
The size of the viewing area for most video software is still pretty small, maybe a few inches square. Transmitting video files large enough to take up a whole monitor would be enormous and would take up even more bandwidth. Many Web site developers to not intend to integrate video until the technology advances another generation, or two.
The inclusion of video on library Web pages has also been quite limited. Finding appropriate applications within the library setting, as well as production facilities and technical staff, may be another reason for limited video integration. Potential library uses for distributing video on the Web could be the delivery of instructional videos and remote tours of library facilities.
Audio
The most common audio file formats and their MIME extensions are µ-law (.au) and WAVE (.wav). The single greatest reason for the popularity of these two formats are their cross-platform compatibility and availability of helper applications. MP3 is a newer compression format that allows faster download times.
This is an example of using an in-line image to link to an audio file.
(format: WAV; Size: 495k)
Practical applications for the use of audio files on library Web sites are quite limited. Potential uses including the delivery of recorded lectures, oral histories, and live events. Creating audio resources into Web documents also requires staff with media production skills. Converting audio from a tape medium into a digital format, or recording it digitally, requires specialized hardware which libraries may not be able to support.
Podcasting
Podcasting is becoming a popular technique for publishing audio content on the web. It is a new broadcasting method that has allowed content creators to create self-published "radio" shows. While the name suggests that individuals must use an Apple iPod, any portable or desktop audio device can be used to playback Podcasts. Podcasts are subscribed to by individuals using podcasting or "aggregator" software which periodically checks for and then downloads new files.
Unlike streaming media, Podcasts are downloaded in their entirety before playback. This allows for high quality content sine it is not contrained by buffering issues during playback since once downloaded the file is local and does not require a network connection.
Synchronized Multimedia Integration Language (SMIL)
SMIL (pronounced "smile") allows Web authors to schedule and choreograph sound, video, text, and other elements on a Web page using simple HTML-style markup tags.
Previously, Web architects looking to create vivid multimedia experiences needed to master complex scripting schemes -- such as JavaScript, Java, Dynamic HTML -- or development tools. SMIL aims to change this by utilizing a handful of simple instructions and a text editor. Authors will be able to layer audio, video, and text on a site or a page by choreographing which media files to "play" when and for how long.
Copyright Concerns
Someone owns the rights to media content found on the Internet. Copying media materials that someone else has already copied could be a copyright violation. The use of existing media may require permission from the author. The Napster debate highlighted many of these copyright issues and concerns.
As with graphics, media content is also subject to fair use rights. Web media can be used by educators, scholars, and students for use or display in connection with lectures or presentations. Other "fair" uses include non-commercial professional development seminars, workshops, and conferences relevant to their disciplines or to present works they created for educational purposes in the course of research, study, or teaching.
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