There are two basic types of Streaming Video which are live webcasts and video on demand or VOD. Due to current
technical restraints, Webcasts are somewhat impractical for most purposes, but streaming video on demand is fairly
easy to set up for the average webmaster.
For video on demand or VOD, the video material is stored on a server so that it is available for viewing at any
time. The proper type of video file must be used so the first step is to edit the video material and save it in the
Most professional video editing software has the ability to save the file in a streaming format, and there is
usually a choice of video sizes and bit rates to suit a variety of connection speeds. The most common video
streaming formats are -
Video streaming formats are compressed, which means that part of the original video is discarded to make for a
smaller file size and faster transmission speeds. There are many video compression schemes but the most common way
to compress video is to take parts of the video image which do not change, such as the background for instance, and
repeat the information, rather than the complete image itself, from frame to frame.
This means that video images which are not 'busy' will compress more and give better results for streaming.
Talking heads are ideal for streaming video, but action packed scenes have too much visual information.
Other things being equal large video files offer better image quality but have the disadvantage of requiring
fast Internet connections. Small video files can be viewed with dialup connections but lose out in terms of image
Bit rate is the rate of data transmission and can range from 56,000 bits per second for dialup to millions of
bits per second for cable connections. Given this range, how can you provide streaming video that will satisfy all
of your viewers? If the video file is too large your dialup viewers will not be able to watch it. If the video is
small enough to be viewed with a dialup connection the quality will be too poor to satisfy your broadband
The simple answer is to provide several versions of the same video. There should be at least three different
versions of any video file.
A large file for fast connections
A medium sized file for average connections
A small file for dialup connections
Viewers simply select which file to view according to their connection speed.
Similar to normal web site files, video files must be stored on a computer called a server. These are
specialized computers that wait for incoming requests and serve the material requested.
Video files can be stored on specialized streaming servers or they can be hosted on a regular HTTP server. HTTP
servers are used for delivering the text and images that make up the average web page, but are unsuitable for
handling a large number of requests for streaming video.
A low traffic website may be able to host a video file on an HTTP server, but web sites which receive
significant traffic with frequent requests for video files should use a video streaming server to host the video
content. Besides being able to handle a large number of requests, video streaming servers also have the advantage
of being able to detect connection speeds and deliver the appropriate video content automatically.