PERSONAL COMPUTER TELECONFERENCE SYSTEM FOR ISDN

摘要

PURPOSE: A personal computer video conference system for an ISDN is provided to increase the convenience of a user by providing a video capture function by a video overlay, an internet connection function and a voice communication with a subscriber of a public switched telephone network in addition to a video conference operation. CONSTITUTION: An analog/digital converter(10) converts a video analog signal into a digital signal. A video processor(20) compresses and encodes the digital signal. A channel connection control unit(30) synchronizes data applied from an ISDN connection unit(40) to a clock and a frame synchronous signal. The ISDN connection unit(40) generates a clock signal and a frame signal. A video overlay unit(50) and a video digital/analog converter(60) overlay video data applied from the video processor(20) and data applied from a video card. An analog MUX/DEMUX unit(70) selects an input/output terminal according to a user's selection. A signal converter(80) converts an analog audio signal applied from the analog MUX/DEMUX unit(70) into a digital audio signal. The DSP(90) converts an ADPCM signal into a digital audio signal. A gain adjustment unit(100) adjusts a level of a voice signal applied from the analog MUX/DEMUX unit(70). A voice communication control unit(110) filters a ring control, a coding/decoding and a voice. An internet control unit(120) provides an internet service. A net channel connection control unit(130) applies state data controlled to a DPRAM(140). A buffer(150) receives and stores specific data.