Abstract: A receiver system automatically adaptively tunes to broadcast signals that are variable in the number of channels that are transmitted, their signal coding type and their modulation format. A system receives a digital bitstream representing video information encoded in one of a plurality of different formats, and transmitted on one of a plurality of transmission channels. The system includes a processor for identifying and capturing program guide information including a plurality of channel maps. A channel map associates a transmission channel with a video channel output and the channel map is also associated with an encoding format. The system also includes an adaptive decoder for decoding the bitstream to provide the video channel output in response to the program guide information.

Abstract: Program Guide information is formed suitable for incorporation in a video program datastream and for storage on a storage medium or for broadcast in variable broadcast encoding formats. A method of formatting video data to be suitable for output on one of a plurality of output channels and in one of a plurality of encoding formats is employed. The method involves forming program guide information including a channel map associating an output channel with a video program. The program guide information also associates the channel map with an encoding format. The program guide information and the video data are incorporated into a datastream and the datastream is provided to an output channel. The method may also involve generating a parameter indicative of an encoding format and combining the encoding format parameter and the channel map in the program guide.

Abstract: A timing recovery system for a digital signal receiver receives a signal, representing successive symbols, from a transmitter. The symbols are subject to exhibiting multiple symbol rates. The system derives a sample enable signal from the received input signal and employs a single, fixed frequency oscillator. A source of samples representing the received signal are sampled at a fixed frequency. An interpolator is coupled to the sample source and is responsive to a control signal. The interpolator produces samples taken at times synchronized to the successive symbols from the transmitter. A phase error detector is coupled to the interpolator, detects a phase error between the sample times of the transmitter synchronized samples produced by the interpolator and times of the successive transmitter symbols, and supplies a phase error signal. The phase error signal is coupled to one input terminal of a summer and a source of a nominal delay signal is coupled to the other.

Abstract: In digital, magnetic and optical storage systems for audio/video/data, a Viterbi detector is extended by a control output, and a PLL is controlled by a variable delay line at the output or inside of the PLL.

Abstract: Apparatus for determining a complexity measure of a data signal is disclosed which includes an encoder, having an input terminal responsive to a data input signal and a data output terminal producing a coded output signal representing the data input signal at a constant bit rate. The encoder includes a variable quantizer, responsive to the data input signal, for producing a quantized signal, representing the data input signal, having a quantizing step size defined in response to a quantizing step size control signal. A bit rate regulator produces the quantizing step size control signal in response to the bit rate of the coded output signal and a quota input signal. A complexity analyzer generates a complexity representative signal related to the quantizing step size and the bit rate of the coded output signal.

Abstract: A complexity determining apparatus is disclosed which comprises a source of a data signal and a subsampler system, coupled to the data signal source, for producing a subsampled signal representing the data signal. A variable bit rate (VBR) encoder is responsive to the subsampled signal and produces an encoded signal representing the subsampled signal. A counter accumulates the number of bits in the encoded signal and produces a complexity representative signal corresponding to the accumulated number of bits.

Abstract: A decimation device for digital data sequences includes a multiplexer mounted in cascade with a calculator producing, alternately, during a first calculation cycle, the mean M.sub.i of at least two data sequences representing the pixels P(i,j) and P(i,j+1) in a line L.sub.i, and during a following calculation cycle, the mean M.sub.c. The mean M.sub.c is composed of the mean M.sub.i and of an intermediate sequence previously calculated and stored in a storage register arranged between an output for the calculation stage and at least one of the inputs to the multiplexer. The intermediate sequence represents the mean M.sub.i-1 of at least two data sequences representing pixels P(i-1,j) and P(i-1,j+1) in a line L.sub.i-1, where i varies from 0 to N-1 and j varies from 0 to M-1.

Abstract: An adaptive decoder generates a program representative datastream, in selectable, encrypted or decrypted form. A method for adaptively processing input encrypted program data with an associated encryption code provides either an encrypted or a decrypted program output. In an encrypted mode, encrypted program data and an associated encryption code is exported to an output port. In a decrypted mode, input encrypted program data is decrypted using an encryption key derived from the encryption code to provide decrypted program data. The decrypted program data is exported to the output port. Non-encrypted program data is exported to an output port in a selectable non-encrypted mode.

Abstract: A CAP signal is processed by a QAM demodulator network. The QAM network causes the CAP signal to rotate about its center frequency, which rotation is removed prior to conveying the CAP signal to utilization networks. In an analog implementation, the CAP signal is frequency upconverted to be centered at Fad/4 so that the QAM processor can use the usual 1, 0, -1, 0 demodulation sequence to bring the CAP signal to baseband. Alternatively, using digital techniques, frequency upconverting is not needed and the 1, 0, -1, 0 demodulation sequence is replaced with a Numerically Controlled Oscillator and full multiplier to allow the QAM processor the bring the CAP signal to baseband.

Abstract: The present invention to provides for information carriers of different storage densities, a recording and/or playback device which is compatible or can be used for different optical information carriers despite a functional relationship which to be satisfied between the size of the information memory location or pit size and the size of the light spot, without changing the wavelength of the laser used or changing the numerical aperture of the objective lens. In order to operate optical information carriers of different storage densities, use is made of an optical system which has a wavelength and numerical aperture matched to the highest storage density, provides a plurality of secondary beams matched to the respective track width, and has a number of secondary beam detector pairs which corresponds to the number of different information carriers.

Abstract: A reproducing and/or recording device for reproducing, or for recording on, an optical recording medium, having a tracking sychronization circuit (1), which has a variable center frequency generator (12, 13). The tracking synchronization circuit (1) can be operated with different center frequencies depending on application, and this has the advantage that identically designed tracking synchronization circuits (1) can be used for different purposes. It is advantageous that adaptive adjustment of a center frequency once prescribed is additionally possible during operation, thus increasing the capture range of the tracking synchronization circuit.

Abstract: A distributed computer system is disclosed which comprises a source of a continuous data stream repetitively including data representing a distributed computing application and a client computer, receiving the data stream, for extracting the distributed computing application representative data from the data stream, and executing the extracted distributed computing application.

Abstract: An adaptive trellis decoder system employs a state transition trellis with a predetermined number of states for decoding a group of interleaved data packets. The trellis decoder system also accommodates data interruptions and transitions between different types of data. The system decodes groups of interleaved trellis encoded data packets with a single trellis decoder in response to a synchronization signal derived from the interleaved encoded data. The decoder employs a state transition trellis with a predetermined number of states. The state transition trellis may be reset to a predetermined state in response to a detected synchronization interval in the encoded data. The decoder may also decode re-aligned data produced by removing intervening synchronization intervals from the interleaved encoded data, in response to a detected synchronization interval.

Abstract: A satellite signal receiver includes an input demodulator followed by a Viterbi decoder and a Reed-Solomon decoder. A received signal is encoded with information including error-representative information, and exhibits an error correction code rate which is a function of the power level of a satellite transmitted signal. The demodulator produces control signals representing the presence or absence of synchronism with the received signal, and signal quality (e.g., signal-to-noise ratio). The Reed-Solomon decoder produces a control signal indicating whether or not error detection and correction is occurring properly. These control signals are sensed by a control network to change the code rate of the Viterbi decoder if necessary.

Abstract: A device for reading from or writing to an optical recording medium is disclosed which has at least two information carrier layers spaced apart from one another, as well as a light source, an optical unit and a detection unit. The device permits a plurality of information carrier layers to be read from and/or written to simultaneously using light of a single wavelength. A partial beam generating element emits two polarized beams which differ in terms of polarization direction and propagation behaviour.

Abstract: A transmitted high definition television signal is represented by a packetized datastream configured as a sequence of data fields with a non-uniform data rate due to different types of different duration non-data overhead information. Each data field is prefaced by a Field Sync overhead segment followed by 312 packetized data segments each with associated overhead information. At a transmitter, a transport processor forms data packets with associated headers and exhibits uninterrupted operation at a constant uniform data rate, while supplying a packetized datastream to a network which constructs sequential data fields by inserting the non-data overhead information into the datastream. The transport processor is advantageously operated at a constant uniform data rate without having to modify the original data field structure to accommodate the needs of the data field construction network.

Abstract: A television signal receiver for processing an HDTV signal transmitted in a vestigial sideband (VSB) format includes input complex filters shared by a timing recovery network (30) and a carrier recovery network (50). The filter network includes a pair of upper and lower band edge filters (20, 22) mirror imaged around the upper and lower band edges of the VSB signal for producing suppressed subcarrier AM output signals. The timing recovery network includes a phase detector (28, 38, 62) and responds to an AM signal derived from the two filters (via 26) for synchronizing a system clock (CLK). The carrier recovery network (50) also includes a phase detector (54, 60, 62, 64), and responds to outputs from one or both of the filters for producing an output error signal (.DELTA.) representing a phase/frequency offset of the VSB signal. The error signal is used to reduce or eliminate the offset to produce a recovered baseband or near baseband signal.

Abstract: A method and apparatus for scaling the bitstream of a compressed video signal includes partial decoding hardware (38, 41) to permit excising of higher frequency AC DCT coefficients or re-quantizing quantized data with a coarser quantization factor. The scaling is performed on a block (macroblock) basis in a manner which linearly scales the amount of compressed data per block. An analyzer (40) generates a profile of cumulative partially decompressed data over a video frame, and bitstream scaling (42) is performed in a manner which insures that a profile of the scaled signal substantially comports with the profile of the original data.

Abstract: A decoder excludes an encryption code or key from decrypted or non-decrypted program output data. Decrypted program representative data is generated from an input datastream containing encrypted program data and an associated encryption code. The encrypted program data is decrypted using the encryption to provide decrypted program data. An output datastream is formed containing the decrypted program data but excluding the encryption code. The encryption code may be excluded by submitting non-encryption code data for the encryption code. The output datastream may also contain ancillary date formed to support decoding of the decrypted program data.

Abstract: Apparatus for asynchronously generating control signals (CONTROL) is disclosed including a plurality of sources (5) of asynchronous data signals and a plurality of data processing channels (10, 14), each processing one of the data signals in response to a control signal (CONTROL). Each of a plurality of parameter determining circuits (10, 16) produces a signal (COMPLEXITY) representing a parameter of one of the data signals. A data sampler (30) samples the signals (COMPLEXITY) from all of parameter determining circuits (10, 16) substantially simultaneously at predetermined sampling time intervals. A control signal generator (30) generates control signals (CONTROL) for the data processing channels (10, 14) having values based on the sampled parameter representative signals (COMPLEXITY) and the preceding sampling time interval.