Abstract: A method for providing local security of audio and video content during transmission and storage within digital home networks. Scrambled content may be recorded in all conditions, however, only authorized copies are processed for descrambling and viewing. Content is protected within a network by rebundling the keys required for descrambling, e.g., the TDES keys, into a new ECM (LECM), which is protected by a local public key.

Abstract: An adaptive digital image processor precedes an MPEG2 encoder. The processor receives a high definition video signal intended for broadcast or storage, and adaptively low-pass filters the signal. The signal is subjected to low-pass two-dimensional filtering to eliminate encoding artifacts and related noise. The video signal is then horizontally down-sampled to create a lower resolution hybrid signal. A receiver decodes and decompresses the hybrid signal. The hybrid signal is upsampled to its original resolution using existing hardware and software with a software modification.

Abstract: A method for providing conditional access (i.e., managing access) to a received scrambled audio/visual (A/V) signal from a variety of sources by utilizing secret sharing for key recovery. Secret sharing eliminates the necessity to protect and transfer the complete descrambling keys between devices, because a portion of the key is stored in the device or a smart card coupled thereto.

Abstract: An adaptive digital image processor precedes an MPEG2 encoder. The processor receives a high definition video signal intended for broadcast or storage, and adaptively low-pass filters the signal. The signal is subjected to low-pass two-dimensional filtering to eliminate encoding artifacts and related noise. The video signal is then horizontally down-sampled to create a lower resolution hybrid signal. A receiver decodes and decompresses the hybrid signal. The hybrid signal is upsampled to its original resolution using existing hardware and software with a software modification.

Abstract: A digital device, such as a digital VTR, receives and records an MPEG compatible datastream. On play back, the DVTR inserts packetized auxiliary information, such as on-screen display information, into the transport datastream for transmission to another digital device, such as a television receiver. Time stamps in the MPEG compatible datastream are unaffected by the insertion of the auxiliary information. The DVTR VSB modulates the datastream to provide sufficient bandwidth for the auxiliary information in the datastream.

Abstract: An image processor produces a DPCM prediction error to be quantized. If the prediction error value is positive, the value passes unchanged to a quantizer. If the prediction error value is negative, a bias value is added to the prediction error value to produce a positive number within the operating limits of the quantizer. Biased prediction error values are quantized. Because all values received by the quantizer are positive and within the current quantizer limits, the quantization table used by the quantizer need not include quantization values for negative prediction error values. This reduces the scope of prediction error values by a factor of two, doubling quantization resolution.

Abstract: An MPEG coded and compressed video signal is received and decompressed for display. Prior to storing frames required for motion compensation in memory, pixel blocks are recompressed into DPCM prediction error values to reduce bandwidth and frame memory requirements. Fixed length quantization and dequantization tables (FIG. 2) have N levels (e.g., 15 levels), and each level has an associated output symbol of predominantly M bits (e.g., 4 bits), except that at least one of said N levels (e.g., level 7) is defined by a unique short symbol having less than M bits (e.g., 3 bits), and input data for that level is received at a desired rate. Each time a short symbol is used to represent a data value, bandwidth and memory are reduced and/or preserved for other uses, for example, inserting overhead data into a fixed-size data stream. For large sequences of data, such as exists for video data for example, the reduction in memory and bandwidth is significant.

Abstract: A memory efficient image processor receives DPCM prediction error values from decompressed MPEG coded digital video signals in the form of pixel blocks containing luminance and chrominance data in a 4:2:2 or 4:2:0 format and recompresses the pixel blocks to a predetermined resolution. Luminance and chrominance data are processed with different compression laws during recompression. Luminance data are recompressed to an average of six bits per pixel, and only a reference pixel and one other pixel are processed separately from all other luminance pixels in a block. Chrominance data are recompressed to an average of four bits per pixel. Each pixel block is stored with overhead information facilitating efficient and accurate reconstruction.

Abstract: In an MPEG compatible image signal processor an MPEG data stream is decoded, decompressed and recompressed before blocks of image pixel values are stored in memory. The recompression system evaluates block data to determine the range and minimum pixel values for a given image block of pixels values. These values are encoded, and the encoded representations are stored in a parameter field with the quantized data block to facilitate data reconstruction. Encoding occurs by fitting the actual range and minimum values to a predetermined set of values. Each selected predetermined value is then encoded as a three-bit index in the parameter field. Storing the encoded values with the quantized data facilitates reconstruction with minimal error. Also, encoding the values preserves memory for the quantized data.

Abstract: An apparatus and concomitant method for constructing a valid OSD message bitstream from a plurality of stored character bitstreams. Each character of the OSD font set is initially scaled into a fixed block size, e.g., a block size of 16.times.16 pixels. Each character is then encoded into a "character bitstream" using the intra macroblock coding syntax. The character bitstream is stored within a storage medium. When a frame of OSD messages needs to be encoded, the character bitstreams are read from the storage medium and cascaded to form a valid OSD message bitstream which represents the frame of OSD messages.

Abstract: A data transmission bus system is disclosed which includes a plurality of nodes coupled together by a ring bus. The ring bus transmits data in successive bus cycles, each bus cycle containing a plurality of bus words. One of the bus words in the bus cycle is a bus cycle synchronization word and the remainder of which are data words. The plurality of data words are allocated to a plurality of data channels.

Abstract: A digital video system receives a digital bitstream representing video and audio information and containing a plurality of packetized data programs in a data format and includes data units related to the selection of individual programs and individual packetized datastreams associated with a program. The system includes a first processor responsive to the bitstream for capturing program guide information and a second processor responsive to the bitstream for capturing selected program data. The program guide data includes a base data unit for selecting a first program and a second data unit of predetermined offset to the base data unit for selecting a second program. The second processor captures program data by capturing data with identifiers matching an identifier determined from the data units.

Abstract: An MPEG compatible decoder receives encoded, compressed data in the form of image representative pixel blocks. The decoder includes a frame memory (20) for storing reconstructed pixel blocks incident to the decoding process. The previously decompressed data is re-compressed (30) before being written to the memory. Stored decompressed data is decompressed for display (34, 26), or as needed for decoding functions such as motion compensation processing (32, 22). The compression performed before writing data to memory is block-based compression using compressed data from one of two different compression paths (FIG. 3, 314, 320) which compress a given pixel block simultaneously.

Abstract: A television receiver with an MPEG decoder is configurable for full high definition decoding and display, or reduced cost lower definition display. The MPEG decoder (10-33) uses a controllable dual-mode data reduction network selectively employing horizontal detail reduction (29) and data re-compression (30) between the decoder and the decoder frame memory (20) from which image information to be displayed (27) is derived. The amount of data reduction is manufacturer selected in accordance with the resolution of the display device, e.g., equal to or less than high definition resolution. The frame memory size is also manufacturer selected in accordance with the resolution of the display device.

Abstract: A television receiver with an MPEG decoder is configurable for full high definition decoding and display, or reduced cost lower definition display. The MPEG decoder (10-33) uses a controllable dual-mode data reduction network selectively employing horizontal detail reduction (29) and data re-compression (30) between the decoder and the decoder frame memory (20) from which image information to be displayed (27) is derived. The amount of data reduction is manufacturer selected in accordance with the resolution of the display device, e.g., equal to or less than high definition resolution. The frame memory size is also manufacturer selected in accordance with the resolution of the display device.

Abstract: A color interpolation circuit allows information uniquely identifying one of six colors to be stored by using only two binary bits of memory storage, and allows information uniquely identifying one of 120 colors to be stored by using only four binary bits of memory storage. This is accomplished by storing only the foreground, edge, and background colors (i.e., herein referred to as "independent" colors), and an "interpolate operator" code, and by providing circuitry to properly interpret and process the interpolate operator code to generate "intermediate colors". This permits a 33% reduction of memory size and reduces the "fetch speed" requirements of associated on-screen display (OSD) scan converter circuitry.

Abstract: A television system for receiving a plurality of digitally-encoded television programs includes circuitry for selecting a particular digital data transmission channel from a plurality of digital data transmission channels containing a desired digitally-encoded television program in response to a control signal, at least one of the data transmission channels also including television program schedule data. The system also includes user-operable data entry circuitry for entering data, and a controller for generating the above-noted control signal in response to user-entered data. The controller selects a virtual channel from a plurality of virtual channels in response to user-entered data, each virtual channel being subject to reassignment to a different one of said a plurality of digital data transmission channels, the television program schedule data defining the relationship of each of the television programs to respective ones of the plurality of digital data transmission channels.

Abstract: In a timekeeping arrangement, including seconds, minutes and hours counters and associated display decoding circuitry, during temporary power line dropouts, the supply voltage for the hours and minutes counters is maintained by an associated voltage storage capacitor so that their contents are retained, and, upon the return of line power, the seconds counter is set to a number corresponding to 30 seconds. In this manner, over a number of random temporary power dropouts, the accuracy of the timekeeping arrangement is maintained without the need of readjustment or the use of auxiliary systems powered by standby power sources.

Abstract: A circuit for storing a DC voltage which may be used to control the volume, brightness, contrast, tint or color characteristics of a television receiver includes a semiconductor switching circuit for selectively coupling a DC voltage to a voltage storage capacitor through a DC impedance path. The DC impedance path is coupled between the inverting and noninverting inputs of an operational amplifier. The output of the operational amplifier is coupled to a utilization circuit to be controlled. A feedback path is coupled between the operational amplifier's output and inverting input to provide negative feedback so that a voltage balance is maintained between the inverting and noninverting inputs and thereby substantially eliminate leakage current flow to or from the storage capacitor through the DC impedance path.

Abstract: A wide bandwidth, ultrasonic frequency transducer drive circuit incorporates a first unidirectional signal path from a source of drive signals to the transducer. A second unidirectional signal path from the source of drive signals couples signals away from the transducer. A circuit resonant with the transducer causes a relatively high signal voltage to be developed across this transducer.