Streaming Video Technologies 353VideoStreaming Video TechnologiesWeb Design in a Nutshell, eMatter EditionAVI (.avi)
AVI (which stands for Audio/Video Interleaved) was introduced by Microsoft in
1992 as the standard movie format to work with its “Video for Windows (VFW)”
multimedia architecture for Windows 95. In AVI files, the audio and video informa-
tion is interleaved every frame, which in theory produces smoother playback.
As of this writing, AVI remains the standard for multimedia authoring on the
Windows platform due to the fact that it comes with the operating system. It can
be used as a basis for converting to most of the streaming media formats discussed
in this chapter.
Macintosh users must install Video for Windows Apple Macintosh Utilities in order
to view AVI movies directly, or use a tool to convert the file to QuickTime format.
MPEG (.mpg)
MPEG is a set of multimedia standards created by the Moving Picture Experts
Group. It supports three types of information: video, audio, and streaming (which
is synchronized video and audio). MPEG was initially popular as a web format
because it was the only format that could be produced on the Unix system.
MPEG files offer extremely high compression rates with little loss of quality. They
accomplish this using a lossy compression technique that strips out data that is not
discernible to the human ear or eye.
There are a number of MPEG standards: MPEG-1 was originally developed for
video transfer at VHS quality; MPEG-2 is a higher-quality standard that was devel-
oped for television broadcast; other MPEG specs that address other needs (such as
MPEG-4 and -7) are currently in development. MPEGs can be compressed using
one of three schemes, Layer-I, -II, or -III. The complexity of the coding (and there-
fore the processor power needed to encode and decode) increases at each level.
Due to this complexity, you need special encoding tools to produce MPEG videos.
To learn more about MPEG, visit the MPEG Web Site(http://www.mpeg.org/ ).
Streaming Video Technologies
As with audio, the competition is fierce in the streaming video arena. Not surpris-
ingly, we see many of the same players as in the audio line-up. New technologies
come and go weekly, so for a current list of contenders, see Netscape’s plug-in
page athttp://www.netscape.com/comprod/products/navigator/version_2.0/plugins/
audio-video.html.
As of this writing, RealNetworks continues to dominate the market due to the
ubiquitous distribution of its player and its proven track record. However, some
competitors offer niche products that may better suit your particular needs. Bear in
mind that QuickTime 3.0 movies will stream without the use of a proprietary
server package.
The following list represents just a few of the options for adding streaming video
to your web site. The web sites listed with each technology provide complete