Abstract: A multimedia firewall adapter supplements a conventional firewall to allow transmission of videoconferencing data (e.g., audio and video data) associated with a protocol, such as the H.323 protocol. The multimedia firewall adapter supplements the conventional firewall so that audio and video data associated with the H.323 protocol are allowed to pass through the multimedia firewall adapter, thus circumventing the conventional firewall. The multimedia firewall adapter receives signals from an intranet and Internet, decomposes the signals, and attempts to authenticate the decomposed signals according to the H.323 protocol. If the decomposed signals are authenticated to contain videoconferencing data, the multimedia firewall adapter negotiates and establishes a connection, and allows the videoconferencing data to pass through. However, if the signal is not authenticated, then the signal is blocked from passing. The blocked signal is redirected to the conventional firewall for analysis.

Abstract: An apparatus and a method is provided for enhancing a digital image comprised of pixels by adaptively sharpening the pixels and clipping the numerical values of the sharpened edge pixels so as to fall between the smallest unsharpened numerical value and the greatest unsharpened numerical value, respectively, of the pixels located within a neighborhood of the pixels. Pixels which are located on an edge are sharpened in the direction perpendicular to the edge. The threshold value used to ascertain the presence of an edge and sharpening parameter used to control the degree of sharpening can be adaptively controlled by the zoom ratio. The apparatus of the invention is particularly suited for an electronic set-top video camera.

Abstract: A system, such as a video conferencing system, is provided which includes an image pickup device, an audio pickup device, and an audio source locator. The image pickup device generates image signals representative of an image, while the audio pickup device generates audio signals representative of sound from an audio source, such as speaking person. The audio source locator processes the image signals and audio signals to determine a direction of the audio source relative to a reference point. The system can further determine a location of the audio source relative to the reference point. The reference point can be a camera. The system can use the direction or location information to frame a proper camera shot which would include the audio source.

Abstract: A personal videoconferencing system includes a videoconferencing appliance connected to a personal computer through a Universal Serial Bus (USB) or similar connection. The appliance is provided with a video camera and microphone for generating local video and audio streams. The local video and audio streams are compressed by a video and audio encoder residing at the appliance, and the compressed video and audio streams are conveyed to the personal computer over the USB connection. The appliance may be further provided with an audio decoder for decompressing a remote audio stream received by the personal computer through a network interface and conveyed to the appliance via the USB connection. A video decoder, located on the personal computer, is configured to decompress the local video stream (received through the USB connection) as well as a remote video stream received through the network interface. The decompressed video streams are then sent to a monitor for display to a user.

Abstract: A technique is provided for reducing power consumption of an internally powered console in an audio system through frequency based signal routing. A system employing the technique includes a base unit having an interface for receiving a signal representative of acoustic information. The base unit includes a filter system for splitting the signal into low-frequency and high-frequency component signals. The low-frequency signal is routed to a first audio driver for reproduction. The high-frequency signal is routed to a device that includes a second audio driver. By removing the need to reproduce the low-frequency portion of the acoustic information, the power consumption of the device is reduced.

Abstract: A presentation device includes an embedded web server for transmitting images representative of presentation information to network-connected terminals concurrently with the display of such presentation information at the presentation site. The images may be viewed at the terminals by pointing a conventional web browser to a DNS name or IP address associated with the presentation device. Certain of the terminals may be given presenter privileges, wherein the users of the presenter terminals may control aspects of the presentation such as slide sequencing by engaging the appropriate controls displayed within the browser window. In this manner, presentations may be viewed and controlled remotely using a conventional browser interface.

Abstract: A system and method for removing noise from a signal containing speech (or a related, information carrying signal) and noise. A speech or voice activity detector (VAD) is provided for detecting whether speech signals are present in individual time frames of an input signal. The VAD comprises a speech detector that receives as input the input signal and examines the input signal in order to generate a plurality of statistics that represent characteristics indicative of the presence or absence of speech in a time frame of the input signal, and generates an output based on the plurality of statistics representing a likelihood of speech presence in a current time frame; and a state machine coupled to the speech detector and having a plurality of states. The state machine receives as input the output of the speech detector and transitions between the plurality of states based on a state at a previous time frame and the output of the speech detector for the current time frame.

Abstract: A positioning device is provided for rotatably positioning a camera or other article about orthogonal rotational axes. The positioning device includes a carriage supported for rotation about a horizontal axis by a yoke. The yoke is in turn rotatably coupled to a base assembly for rotation of the yoke about a vertical axis. Rotation of the camera about the horizontal and vertical axes is respectively effected by first and second voice coil actuators, each comprising a pair of magnets and at least one coil to which current is supplied. The amplitude and direction of the current supplied to the coil determines the speed and direction of rotation of the camera. The second voice coil actuator preferably includes a coil assembly comprising two opposed coils. This design overcomes the angular range limitations associated with prior art voice coil actuators and enables rotation of the camera about an extended angular range.