[Analysis of the development process of high-definition video conferencing system technology] Video conferencing system technology introduction
Content navigation: Page 1: The development process of video conferencing technology Page 2: The development of high-definition video conferencing systems Page 3: Standards for high-definition video conferencing Page 4: Technical requirements for high-definition video conferencing
The development process of video conference technology
Video conferencing is a typical example of multimedia communication applications. Developed countries began to conduct research on video conferencing in the 1960s. Early video conferencing systems were transmitted in an analog manner, occupying a large bandwidth. The representatives include the video phone developed by Bell Labs in the United States and the 1MHz bandwidth black and white video conferencing by BT in the United Kingdom. system. In the late 1980s and early 1990s, with the development of microelectronics, computers, digital signal processing and image processing technology, the theoretical research and practical system development of video conferencing have also been rapidly developed. In general, its development has mainly experienced three stages: analog video conferencing, digital video conferencing, and internationally unified digital video conferencing.
Since the 1960s, developed countries in the world began to study analog video conferencing systems and gradually commercialized them.
In the late 1960s, under the impetus of compression coding technology, the analog system turned to the digital system.
In the early 1980s, a 2Mbps color digital video conferencing system was developed, and Japan and the United States formed a non-standard domestic video conferencing network.
In the mid-1980s, the rapid development of large-scale integrated circuit technology, breakthroughs in image coding and decoding technology, and reduced channel costs provided good development conditions for video conferencing to become practical.
From the end of the 1980s to the present, multimedia technology, computer technology, and communication network technology are changing with each passing day. CCITT (now ITU-T) formed the H.200 series of recommendations, which stipulated unified video input and output standards, algorithm standards, error checking standards and a series of interoperable mode conversion standards, which resolved the interoperability of equipment from different manufacturers Problems have greatly promoted the development of video conferencing.
Since the mid-1990s, the rapid development of the computer Internet has had a huge and profound impact on the telecommunications industry. Multimedia communication systems based on packet-switched networks have gradually become one of the focuses of researchers and telecommunications, network and computer manufacturers. The Internet Engineering Task Force (IETF) has also developed the Real-Time Transport Protocol (RTP) and Resource Reservation Protocol (RSVP) to cooperate with the ITU-T H.323 recommendations to ensure the transmission of real-time audio and video streams on the IP network.
From the history of the development of video conferencing technology, at present, the establishment of video conferencing systems can be carried out according to the two ITU-T framework recommendations H.323 and H.320, thus forming two different construction plans. H.320 is an earlier video conferencing standard of ITU-T. The standard is completely based on a series of proprietary technologies and standards for video conferencing, while the H.323 standard is based on a common and open computer network communication technology foundation. It has broad prospects for development. Since ITU-T approved the standard in 1996, the technology and market of video conferencing have undergone revolutionary changes. More and more manufacturers are racing to develop new H.323 products, and more and more users adopt H.323 technology and products to construct their own video conferencing systems. This is an inevitable trend brought about by the rapid development and increasing integration of communication network technology, computer technology and multimedia technology. Moreover, the H.323 system has increasingly demonstrated its obvious advantages over the H.320 system in terms of technological advancement, functional integrity, ease of operation, system scalability, and performance-price ratio.