Vtel Corporation

Compuadd, Corporation

Paul V Tischler

Bill Clements

Joon Maeng

Theodore E Weber

A method for determining a talk/listen state using voice detection includes receiving an audio sample and detecting whether the audio sample includes voiced sound. The audio sample represents sound measured during a sample time interval. The method further includes deriving an audio level from the audio sample and comparing the audio level to a threshold level. The audio level represents an average power level of the audio sample. The method further includes determining the talk/listen state depending on a relation of the audio level to the threshold level and depending on whether the audio sample includes voiced sound.

Primary transmission site switching in a multipoint videoconference

A method for determining a talk/listen state using a dynamic threshold is provided that can be implemented in a multipoint control unit (12). An audio sample is received and represents sound measured during a sample time interval. An audio level is generated from the audio sample The audio level represents an average power level of the audio sample. A dynamic threshold is set by processing the audio level. The audio level is compared to the dynamic threshold. A talk/listen state is determined to be a talking state if the audio level is above the dynamic threshold and to be a listening state if the audio level is below the dynamic threshold. The previous steps are repeated for each audio sample in a sequential stream of received audio samples such that the dynamic threshold is maintained and used to determine the talk/listen state.

Method for talk/listen determination and multipoint conferencing system

A multipoint video conference system (8) is provided that has video rate control and allows communication of audio, video and data information between end-point units (16). The multipoint video conference system comprises a multipoint control unit (10, 20) having a plurality of interface units (12, 22) located therein. Each interface unit (12, 22) is operable to communicate with other interface units (12, 22) via a backplane (14, 24) of the multipoint control unit (10, 20). A plurality of end-point units (16) are each coupled to an associated interface unit (12, 22). Each end-point unit (16) is operable to communicate and process real data information and operable to receive and resend fill data information. The multipoint control unit (10, 20) is operable, with respect to each participating end-point unit (16) in a data channel, to allow communication of real data information and, with respect to each non-participating end-point unit (16), to allow communication of an equal amount of fill data information. Each interface unit (12, 22) is operable to transmit real data information to a participating end-point unit and to transmit fill data information to a non-participating end-point unit (16). Each non-participating end-point unit (16) is operable to retransmit fill data information back to an associated interface unit (12, 22) such that available bandwidth for video information remains balanced for all end-point units (16) when a data channel is open between participating end-point units (16).

Process and system for video rate control in a multipoint video

A controller (10) for use with a hard disk (38) or other mass storage medium provides a memory cache (36). A block descriptor table (40 ) is divided into a plurality of sets (42), depending upon the size of the memory cache (36). Each set is similarly indexed to define memory groups (44) having tag, cache address, and usage information. Upon a read command, an index is generated corresponding to the address requested by the host computer, and the tag information is matched with a generated tag from the address. Each set is checked until a hit occurs or a miss occurs in every set. After each miss, the usage information (50) corresponding to the memory group (44) is decremented. When reading information from the storage device (32) to the memory cache (36), the controller (10) may selectively read additional sectors. The number of sectors read from the storage device may be selectively controlled by the user or the host processor. Further, a cap may be provided to provide a maximum number of sectors to be read.

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Austin, TX, United States of America

Paul V Tischler