摘要:
A method and system for information processing in a bidirectional information transmission system, particularly for transmitting information in accordance with a change in a transmission capacity of a transmission line. A system is provided which can change an information transmission rate in accordance with a room capacity of a transmission line. This information transmission system includes a plurality of information providers, a plurality of information receivers, an information storage and distribution unit connected to the information providers and receivers, and a plurality of information transmission lines for information transmission between the information providers and receivers and the information storage and distribution unit, wherein the information transmission rate of each information transmission line is changed.
摘要:
A method and system for information processing in a bidirectional information transmission system, particularly for transmitting information in accordance with a change in a transmission capacity of a transmission line. A system is provided which can change an information transmission rate in accordance with a room capacity of a transmission line. This information transmission system includes a plurality of information providers, a plurality of information receivers, an information storage and distribution unit connected to the information providers and receivers, and a plurality of information transmission lines for information transmission between the information providers and receivers and the information storage and distribution unit, wherein the information transmission rate of each information transmission line is changed.
摘要:
A display system for displaying a plurality of video windows on a display screen. A receiving element is included for receiving video data packets from a plurality of video sources in a time sharing manner, each of the video data packets including: coded video information for representing a partial image contained within one of a plurality of blocks constituting a video frame; attribute information for indicating at least a location of a block corresponding thereto within the video frame; and identification information of the video source. A decoder element is connected to the receiving element for decoding the coded video information extracted from each of the video data packets and for outputting a partial image corresponding to one of the blocks in the video frame. A set of frame memories are included for assembling partial images into video frames, each of the frame memories having a plurality of window areas located in a predetermined layout defined therein, and a set of the window areas each located at a same location within respective frame memories being associated with a same video source with respect to each other. A writing element is included for writing each partial image derived from the decoder element into one of the window areas within one of the frame memories which is specified in accordance with the identification information extracted from a video data packet related to the partial image and a utilization status of the window areas. Finally, an outputting element is included for selectively outputting contents of the frame memories on a display screen by changing over the frame memories depending upon a display position on the display screen thereby to present a plurality of video frames at a plurality of window areas on the display screen.
摘要:
A constant voltage circuit according to this invention comprises first means attenuating or dividing fluctuating voltage and an amplifying FET, to the gate of which the output attenuated or divided by the first means is applied and whose drain is connected with the fluctuating voltage through load means. The attenuation ratio or division ratio of the first means, the mutual conductance of the amplifying FET and the impedance of the load means are so set that the voltage drop across the load means cancels the fluctuating amount of the fluctuating voltage. Consequently an output voltage, which is maintained substantially constant, is obtained at the drain of the amplifying FET, independently of fluctuations in the fluctuating voltage, and thus a constant voltage circuit can be obtained. A constant current circuit according to this invention utilizes the constant voltage circuit described above. The output voltage of the constant voltage circuit is supplied to the gate of the constant current FET. Consequently a current, which is maintained substantially constant, flows through the drain-source path of this constant current FET and thus a constant current circuit can be obtained.
摘要:
The video information recording and reproducing apparatus includes an inputting information part for receiving video information, a storing information part, an outputting information part for producing video information, an automatic indexing information part for automatically adding indexes to the inputted video information, a filtering video information part for automatically selecting video information to be stored from the inputting information part, and a controlling part for controlling the above elements, thereby actualizing the free time-shift viewing function, intelligent search function, and automatic video data base generation function.
摘要:
A multi-point visual communication system which includes an adaptive filter part for controlling a spatial frequency characteristic of a video signal, a filter selector for selecting a video quality to be transmitted from its own site on the basis of integrated requests received from sites, and a filter control for adaptively controlling a filter characteristic taking both of a video information quantity and situations of a telecommunication network into consideration, and wherein a video signal processed by the adaptive filter part is subjected to an encoding operation and then transmitted to the telecommunication network. Thereby, the video quality can be selected according to users' requests, and the video quality of the multi-point visual communication can be improved without incurring an excessive increase of a video information quantity. Further, through the video signal processing taking both the video characteristic and the telecommunication network situations into consideration, a comparatively high quality of video transmission can be realized when viewed from an information quantity.
摘要:
A real time visual communication system capable of improving a correspondence between a received video signal and a received audio signal in real time and improving reality. An AV signal is separated into a video signal and an audio signal, and the output state of the video or audio signal is controlled by the characteristics of the audio or video signal. For example, the sound field, reverberation, and the like are controlled in accordance with the characteristics of the video signal. A suitable image pickup unit is selected in accordance with the characteristics of the audio signal to make the sights of conversation participants coincide with each other. It is possible to reproduce sounds of audio signals well matching video signals and to provide visual communication having good reality because of the combination of matched audio and video signals.
摘要:
A multi-point video conference system includes a plurality of terminals and a network. Each terminal includes a coder to code and to packetize at least a motion picture in a block unit and a multi-point video decoder to sequentially receive and to decode packets sent from decoders at other points. The decoder includes a video processor to process video information in a time sharing manner, a channel selection controller to decide a transmission source of a received packet according to information of the packet and to notify the source to the video processor, a shared frame memory to store therein video information from the plural terminals, and a display frame memory to output therefrom the video information in a synchronous fashion.
摘要:
A video signal transmitting method comprising: a sending method including the steps of: dividing an analog video signal in a unit corresponding to integer times of a number of bits composing an information field of one packet in packet transmission and converting into a digital video signal, forming a digitalized video signal into a plurality of packets, forming a plurality of packets into a first packet block in M lines.times.N columns, adding an error correction code which corrects a longitudinal error of data in a first packet block as a second packet block in P lines.times.N columns in an (M+1)th line and thereafter, and sending a packet; and a receiving method including the steps of: recomposing the same packet block as that composed on a sending side from plurality of received packets, recovering a video signal with packet loss information from an exchange and an error correction code formed into a packet, and regenerating an analog video signal from a digital video signal after recovery.
摘要:
A constant current circuit includes a first FET providing an input reference current flow, a second FET providing an output current flow and a non-linear impedance element connected between the drain and the gate of the first FET. By setting a parameter of the non-linear impedance element and a parameter of the first FET to have a specific relationship with each other, the output current can be maintained at a substantially definite value irrespective of relatively large variations of the input reference current.