Abstract: A system for use with a CATV settop terminal measures the input RF carrier signal power level at several frequencies within the CATV RF input bandwidth upon system power-up. The system utilizes these measurements to selectively equalize and process the RF input signal depending upon the carrier frequency selected and the desired signal level to be input to the RF tuner. The system refines the signal level by specifically measuring the signal level of the selected carrier frequency. The system further improves RF tuner performance by dynamically limiting the bandwidth input to the RF tuner depending upon the selected carrier frequency.

Abstract: A motion estimation and compensation technique is provided for interlaced digital video such as video object planes (VOPs). Predictor motion vectors for use in differentially encoding a current field coded macroblock are obtained using the median of motion vectors of surrounding blocks or macroblocks. When a surrounding macroblock is itself interlaced coded, an average motion vector for that macroblock is used, with fractional pixel values being mapped to the half-pixel. When the current block is not interlaced coded but a surrounding block is, the field motion vectors may be used individually or averaged. In a repetitive padding technique for an interlaced coded VOP, the even and odd lines of the VOP and surrounding block are grouped. Within each field, exterior pixels are padded by setting them to the value of the nearest boundary pixel, or to an average of two boundary pixels. The lines are then reordered to provide a single padded reference VOP image.

Abstract: A system for coding of digital video images such as bi-directionally predicted video object planes (B-VOPs), in particular, where the B-VOP and/or a reference image used to code the B-VOP is interlaced coded. For a B-VOP macroblock which is co-sited with a field predicted macroblock of a future anchor picture, direct mode prediction is made by calculating four field motion vectors, then generating the prediction macroblock. The four field motion vectors and their reference fields are determined from (1) an offset term of the current macroblock's coding vector, (2) the two future anchor picture field motion vectors, (3) the reference field used by the two field motion vectors of the co-sited future anchor macroblock, and (4) the temporal spacing, in field periods, between the current B-VOP fields and the anchor fields.

Abstract: Computer data provided according to a first data protocol, such as the Internet protocol, is communicated over a digital television broadcast network using a second data protocol such as MPEG2. The computer data in the first data protocol is encapsulated in at least one data stream for distribution in conformance with the second data protocol. The at least one data stream encapsulating the computer data is multiplexed with a plurality of data streams conforming to the second data protocol for transmission over the network, which may be a cable or satellite television network. The data stream encapsulating the computer data is received from the network according to the second data protocol, and processed in accordance with the second data protocol to recover the computer data in the first data protocol.

Abstract: Textual and graphical displays are provided on a television screen using a hypertext markup language (HTML). On-screen display devices allow a user to invoke hyperlinks to different pages of HTML-coded data in addition to functions calls for controlling television and non-television appliance functions. A method provides HTML-coded display data which is processed to provide a signal suitable for reproduction on a television. The display data may provide information on a featured movie or other presentation of an associated video programming service signal such as a network television broadcast. Function calls allow the control of various television functions and programming options, such as the purchase of pay-per-view programming, or television display options such as aspect ratio, channel, brightness, picture-in-picture, or split-screen. Non-television appliances which may be controlled with function calls include audio equipment which is associated with the programming service (e.g.

Abstract: A peripheral device is provided for a personal computer enabling the PC to provide the functions of a set-top box for television reception. Communication of television and control signals between the television and PC can be provided over the cable wiring already provided in the subscriber premises. Alternatively, wireless communication can be provided between the television and the PC. The invention obviates the need for a set-top box and the associated expense thereof. The television operations take place in the multitasking environment of the PC, so that the PC can be concurrently used for other applications.

Abstract: A television viewer can easily navigate programs which are grouped according to a common service provider or other grouping criteria by depressing the "channel up" or "channel down" buttons on a hand-held remote control. Programming services which are provided via one or more transmission paths are integrated, thereby allowing a viewer to successively select the grouped channels regardless of the broadcast signal, transmission path, frequency spectrum, transport stream and/or PID in which the channel is carried. Data is provided with broadcast signals to indicate broadcast address information which corresponds to a primary channel and one or more secondary channels of a channel group. A viewer can successively view the channels of the group while bypassing intermediate non-group channels. Grouped channels can thus be designated by a common channel designator such as a channel number.

Abstract: DC and AC DCT transform coefficients of an INTRA coded block are differentially encoded by selecting predictor DC and AC coefficients from a left-hand neighboring block and a top neighboring block. Each block is coded according to a frame mode, a reordered field mode, and a non-reordered field mode. The AC predictor block is selected according to the respective coding modes of the blocks, and the block in which a DC predictor resides. The top block is selected as an AC predictor when the top block and current block are both reordered field mode, or both frame mode and/or non-reordered field mode, and the DC predictor resides in the top block. Zeroed AC spatial transform coefficients are used in place of the AC spatial transform coefficients from the selected block when the selected block is not INTRA coded, or does not reside in the same Video Object Plane (VOP) as the current block. DC coefficients may be non-linearly quantized.

Abstract: An automated signal generator apparatus allows testing of remotely-controlled electronic devices to verify functionality and reliability, or for product set-up, initialization or configuration. The apparatus simulates a person pressing the keys on a remote control key pad, and can simulate key press sequences, key press duration, and time between key presses. Other human interfaces may also be simulated. The apparatus can be continuously driven by an external computer in a slaved mode, or can store test instructions in an internal memory to operate in a standalone mode. Test instructions, which may be written in a macro script language, are processed by a microprocessor to provide a control signal to, e.g., an infrared (IR) transmitter. The IR transmitter can control one or more electronic devices which are under test. The transmitter may use a wide angle IR beam, or a plurality of separate transmitters for testing of a plurality of electronic devices at the same time.

Abstract: A current pixel of a video image is adaptively filtered to provide stronger filtering when there is a high likelihood that noise is present. Weaker filtering is provided when the presence of a color and/or brightness edge is likely in the video image. Each pixel has luminance and chrominance amplitude values. In a filtering method, a current pixel is intermediate to first and second pixels in the video frame. Difference signals are determined based on the amplitude difference between the current pixel and first and second adjacent pixels. A plurality of available filters provide successively stronger filtering of the current pixel amplitude. One of the filters is selected for filtering the current pixel according to the difference signals. Secondary difference signals which indicate the amplitude difference between the current pixel and pixels which are adjacent to the first and second pixels are also considered in the selection process.

Abstract: A CATV passive signal component is disclosed performing bidirectional power insertion or extraction while providing directional RF signal splitting. The signal splitter presents a low burden to the distribution system and can bidirectionally pass alternating or direct current already impressed on the RF signal, or, provide an insertion or extraction function.

Abstract: Data overflow in a buffer of a set-top decoder for receiving asynchronous data, such as digital television signals, is prevented while also maintaining compliance with an interface timing standard such as the RS404-A standard. A fullness level of the buffer is monitored to determine whether the fullness falls within a first, nominal range, or into second or third higher ranges. A clocking signal is derived from a ratio of a fixed reference clock signal and a divisor for outputting asynchronous data from the buffer at a desired rate. A direct digital synthesis (DDS) circuit may be used to provide a fractional divisor. The divisor is selected to provide the clocking signal at a rate so that a difference between a target output rate and the actual output rate falls within a data performance standard such as the RS404-A standard.

Abstract: A device which eliminates all RF ingress noise from entering the CATV network in the upstream communication path includes a shunt filter, a detector and a filter with a bandwidth equal to the bandwidth of the upstream communication path. The device monitors signals transmitted in the upstream bandwidth and detects when a valid upstream communication is being transmitted. Upon detection of this valid signal, the shunt filter is switched out of the upstream communication path to allow the valid transmission to be sent. When the end of the valid transmission is detected and a predetermined delay has lapsed, the shunt filter is switched to block all upstream transmissions in the upstream communication bandwidth.

Abstract: A video data stream analyzer modifies an input digital video signal so that the resulting output digital signal can be optimally compressed by a digital video encoder. The video data stream analyzer eliminates redundancy in the input video signal, and reorganizes the input video signal so that the spatial and temporal redundancy is increased. In addition, the video data stream analyzer generates side channel information that is supplied to the video encoder. The side channel information tells the video encoder whether vertical frame-based filtering or vertical field-based filtering is preferable. Additional side channel information specifies the order and duration of the display of the fields after decoding and this information preferably is encoded with the video signal.

Abstract: A secondary packetized data stream, such as a commercial, is spliced with a primary packetized data stream, such as a network television program. The system does not require decompression of the data in the primary data stream, and is particularly suitable for use at a cable system headend to allow the insertion of commercials from local businesses into a nationally broadcast television program. When a start signal is received, a pre-splicing packet of the primary stream is determined. The pre-splicing packet is the packet closest to the start time which carries an anchor frame (e.g., I or P frame) start code. To prevent a potential discontinuity at the decoder, the pre-splicing packet is processed to discard the anchor frame data, and to insert a number of stuffing bytes which is equal to the number of bytes discarded into an adaptation field of the pre-splicing packet.

Abstract: A voltage converter transforms a high voltage alternating current (ac) input source into a lower voltage direct current (dc) output voltage. The line frequency of the ac current switches an electronic switch to alternately reconfigure a combination of capacitors and diodes to perform energy storage and effect voltage division. The dc output voltage is approximately one half of the peak ac input voltage at no load.

Abstract: A method and apparatus are provided for convolutionally encoding digital data with a rate 5/8 convolutional code. A standard rate 1/2 convolutional code is punctured to rate 5/8 using a puncture map of ##EQU1## and octal generators 133, 171 wherein the constraint length K=7. An incoming data stream is processed using the rate 5/8 code. In another embodiment, a rate 1/3 convolutional code is punctured to rate 5/8 using a puncture map of ##EQU2## and octal generators 117, 135, 161 wherein the constraint length K=7.

Abstract: The effects of noise in a video processing system are reduced, resulting in improved image quality. A digital video signal containing a luminance component in Y color space is processed by increasing the amplitude of the luminance data in accordance with a nonlinear transfer function. As a result, low-amplitude components of the luminance signal are reduced. Subsequent quantization errors in transform coefficients produced by a spatial compression routine in a video encoder are consequently reduced. Inverse operations are performed at a video decoder to recover the original luminance data. The invention reduces quantization noise which is manifested particularly as dust-like variations in luminance intensity in an otherwise darkened region of a video image. A decoder apparatus is also presented.