- jackLv 71 十年前最愛解答
A modern 2 screen video conferencing system. The Plasma on the left is used primarily for displaying people and the user interface. The plasma screen on the right is generally used for displaying data, but can be used to show a 2nd 'far site' during a multipoint call.
A videoconference (視像會議) (also known as a videoteleconference) is a set of interactive telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously.
The core technology used in a videoteleconference (VTC) system is digital compression of audio and video streams in real time. The hardware or software that performs compression is called a codec (coder/decoder). Compression rates of up to 1:500 can be achieved. The resulting digital stream of 1's and 0's is subdivided into labelled packets, which are then transmitted through a digital network of some kind (usually ISDN or IP). The use of audio modems in the transmission line allow for the use of POTS, or the Plain Old Telephone System, in some low-speed applications, such as videotelephony, because they convert the digital pulses to/from analog waves in the audio spectrum range.
The other components required for a VTC system include:
Video input : video camera or webcam
Video output: computer monitor , television or projector
Audio input: microphones
Audio output: usually loudspeakers associated with the display device or telephone
Data transfer: analog or digital telephone network, LAN or Internet
There are basically two kinds of VTC systems:
Sorry, no Chinese version.
- Adam LauLv 51 十年前