The combination of video conferencing and collaborative computing represents the key components of the multimedia conferencing applications. The intent of this document is to provide information on technologies necessary for multimedia conferencing applications. This paper is focused on the audio and video compression methods, ways of data transmission over various types of networks and interoperability standards. Today videoconferencing can be achieved by adding software and relatively inexpensive hardware to standard desktop computers. Such systems, also, have the ability to easily incorporate data from other desktop computer applications into the conference.
Next chapters discuss the enabling technology for videoconferencing.
First, audio and video must be captured from their analog form and stored digitally to be manipulated by the computer. Uncompressed, this data would require massive amounts of bandwidth to transmit, therefore the data is compressed before it is sent over communication channels. All this must happen in real-time to enable communication and interaction. The human ear can typically perceive frequencies between 20 Hz and 20 kHz. Human voice can typically produce frequencies between 40 Hz and 4 kHz.