Abstract: Difference signals generated in the prediction encoding process for an input digital information signal are block segmented. The maximum value and minimum value of each block are detected. In addition, a quantizing step .increment. is calculated. An offset detecting circuit detects a zero position flag ZR and an offset off. The zero position flag ZR represents a quantized code that includes 0. The offset off represents the deviation between value 0 of difference signals and value 0 of restored representative values. A class category adaptive predicting circuit predicts ZR and .increment.. These values are not transmitted in other than exception process. With predicted values ZR and .increment., difference signals corrected with the offset off are quantized by a quantizing circuit.

Abstract: A method and apparatus for processing data using data compression. During compression, a relationship between a next data word and a previous data word is determined and that relationship is encoded into variable bit-length code words, the bit-length being inversely proportional to the probability of occurrence of the relationship between the data words. The encoded relationships are transmitted rather than the data words themselves. In one embodiment, a look-up table of code words is stored which is indexed according to the possible relationships. A relationship is determined between the previous and next data words and the relationship is matched to the index to find the corresponding code word in the look-up table. The corresponding code word is retrieved from the look-up table, is substituted for the relationship, and is transmitted.

Abstract: A method for compacting and storing date information in multiple calendar systems. Alphanumeric data corresponding to the day, month and year are entered, including "?" characters for values or individual digits that are unknown or uncertain. The year data is converted to a base eleven number for compaction and then further converted to a binary number for storage.

Abstract: In a computer implemented method for encoding digital values that are arranged in a successively increasing order, a delta value is determined for each pair of immediately successive values. The delta values are the differences between the pair of immediately successive values. For each delta value which can be encoded as a single byte, a logical zero is stored in the least significant bit of the single byte, and the delta value is stored in the most significant bits of the single byte. Otherwise, for each delta value which must be encoded as a plurality of bytes, a logical one is stored in the least significant bit of the first byte of the plurality of bytes, and a first portion of the delta value is stored in the most significant bits of the first byte. In this case, a logical zero is stored in the most significant bit of the next byte, and a next portion of the delta value is stored in the least significant bits of the next byte.

Abstract: A high-order oversampling modulation apparatus is disclosed herein. The present invention implements a high-order oversampling modulation apparatus by use of a plurality of shift registers in response to clock signals provided with a frequency higher than the sampling rate in order to simplify the circuit and layout.

Abstract: An audio data coding method of requantizing digital audio data in accordance with the hearing sense characteristic of the human being, comprises: the steps of calculating a quantization error; calculating a level correction value from the calculated quantization error and a level of an input signal; and carrying out level correction of the digital audio data in accordance with the level correction value. In addition, there is provided an audio data coding apparatus for implementing the above-mentioned audio data coding method.

Abstract: A speech coding transmission system is disclosed in which a coder of a differential coding system quantizes a difference between a predictive value from an adaptive predictor and an input speech signal by an adaptive quantizer in accordance with the level of the latter and to send out the resulting coded signal to transmission medium, and a decoder outputs a reproduced speech signal on the basis of a residual signal obtained by inversely quantizing a received coded signal with an inverse adaptive quantizer and a predictive value from an adaptive predictor. Both or either one of the coder and the decoder includes a comparator-attenuator which attenuates the amplitude of the input signal or reproduced speech signal to a value smaller than a predetermined threshold value and applies to the amplitude-attenuated speech signal to the adaptive predictor.

Abstract: The differential coding apparatus comprises a delay unit for storing an adjacent value, a transmission value conversion unit for assigning a transmission value to a value of difference between the value to be coded and the adjacent value in the ascending order of the absolute value of the difference value, and a variable-length coding device for assigning a code in the order that the code is increasing in code length as the transmission value increases in number. In the range in which positive and negative difference values exist, positive and negative numbers are alternately given to difference values in the order in which the difference value is increasing in distance from a center difference value of 0. In the range in which either positive or negative difference value exists, serial numbers are successively given to difference values in the order in which the difference value is increasing in distance from the difference value of 0.

Abstract: A method and apparatus for compressing a data vector of a predetermined number of data points. The apparatus includes a memory for storing the compressed data vector, a first comparator for determining a largest and smallest data point of the data vector and a second comparator for comparing the largest and smallest data point and when they are equal, causing a first data point of the data vector to be stored in the memory as the compressed data vector. The apparatus also includes a first processor for determining a data field width necessary to uniquely describe a largest relative magnitude data point and a second processor for storing the data points of the data vector as the compressed vector in data fields of memory of the data field width.

Abstract: Known systems based on stereoscopic video coding and video decoding code with inadequate efficiency because the left-hand picture and the right-hand picture are coded and decoded independently of one another by means of the encoders present in the system. As a result of providing one encoder with switching means to which a signal representing the left-hand picture and a signal representing the right-hand picture are fed, said encoder is able to base the prediction either on the left-hand picture or the right-hand picture, and this improves the prediction and, consequently, the efficiency of the coding.

Abstract: A division technique unified quantizer-dequantizer circuit is disclosed. The unified quantizer-dequantizer includes a division circuit receiving a half step size q and an input signal x. The division circuit outputs a quantized coefficient signal y and a remainder R, where ##EQU1## The unified quantizer-dequantizer also includes a circuit receiving the quantized coefficient signal y, the remainder R, the half step size q and the input signal x.

Abstract: Known transcoders for compressed video signals comprise a decoder and a coder coupled thereto, between which a data signal is transmitted. Because compressed video signals comprise so-called difference pictures and normal pictures, both the decoder and the coder should have a feedback loop which is utilized in decoding and coding a difference picture and is not utilized in decoding and coding a normal picture. For example, for the purpose of prediction means (motion compensation and motion estimation) present in the feedback loop of the coder, much computation has to be carried out in the coder. The computation required is considerably reduced by concomitantly transmitting one or more information signals in addition to the data signal in a transcoder according to the invention, and complete decoding and complete coding no longer takes place.

Abstract: A codec uses a number of different signal processing techniques to improve audio compression. These techniques include (1) dynamically varying the size of the processing block to match the duration of the signal over which the audio signal can be considered to be substantially constant, (2) reducing the power gain of the LPC coefficients to reduce leakage of coding noise from one block into the following block, (3) allocating bits to the residual signal in accordance with both objective and subjective criteria, and (4) computing a modified residual signal to take into account the zero input response of the synthesis filters to the reconstruction noise of past blocks.

Abstract: Speech signals coded according to the principle of high-resolution long-term prediction (HLTP) have a high accuracy due to the high-resolution which causes a high complexity. The ordinary LTP method is improved by use of oversampling and determining subsegments Cd lying in a preceding segment which precedes a subsegment to be coded, for which it is the case that the number of samples Dd, expressed in the numbers of samples after oversampling, between the initial time instant of the subsegment to be coded and the initial time instant of a subsegment Cd, fulfills the relation Dd=(D*Ob)/d, in which d=2,3,4 . . . n, where n is a positive integer and where Ob and n are chosen in a manner such that Dd is always an integer. Null sample values produced initially for oversampling are given significance by means of an interpolation technique, at predetermined positions which are situated at a spacing Dd from the original samples in the subsegment to be coded.

Abstract: The output gates of a delta-sigma modulator can generate i(t) transient signal in the power supply lines of a delta-sigma modulator. These i(t) spikes, which would otherwise produce non-linearities which can be coupled into the frequency band of interest of the modulator, are made to be linear by using return-to-zero data encoding and by providing multi-bit outputs to the delta-sigma modulator in which the output states all have equal numbers of logic ones at the output lines for each of the output states.

Abstract: The present invention provides a circuit for use in an ADPCM synthesizer for generating a function of a quantization step without the use of a look-up table. Illustratively, the function is represented in a piecewise linear fashion. This permits an ADPCM synthesizer to be implemented without the use of a memory storing a look-up table for the function so the area of the synthesizer chip can be reduced.

Abstract: Known systems based on layered coding and decoding do not take account of the greater surface area of an HDTV picture, which is to be coded with high resolution, compared with the smaller surface area of a conventional picture, to be derived therefrom, which is to be coded with low resolution. An improvement in the efficiency of the coding and decoding is achieved by actually taking account of this with the system according to the invention and maintaining the coupling between the two layers in the encoder and the decoder if a picture element is situated in a corresponding section of the two pictures and interrupting the coupling if a picture element is situated outside the corresponding section of the two pictures.

Abstract: A noise shaping circuit and a noise shaping method, in which a quantization error generated in a requantizer is taken out at a subtractive node and fed back to an input of the requantizer via a noise filter. A dc detector detects if the input signal from an input terminal is of a dc value including zero. If the input signal is detected to be a dc signal, the feedback quantity is reset to zero to prevent the oscillation by the limit cycle and to prevent the hunting phenomenon from occurring.

Abstract: A method of processing a first series of values representing a row of pixels of a digitized image for differentially encoding the first series of pixel values to generate a first series of codes representing a first series of differential values; expanding each code of the first series into a group of codes to form a second series of codes, each group of codes representing a plurality of differential values whose sum is the differential value represented by the corresponding code of the first series; and decoding the second series of codes to generate a second series of pixel values for display. By transmitting or recording the first series of codes and then effectively dividing each received or reproduced differential value into two or more smaller differential values, known apparatus can be made with little modification to expand each line of a received image by a factor of two or more, depending on the number of codes in each group.

Abstract: Known systems based on layered video coding and video decoding code with inadequate efficiency because a new high-resolution picture is predicted by means of switching means present in the system either on a basis of the preceding high-resolution picture or on the basis of an instantaneous low-resolution picture. According to the invention, designing the switching means for a adjustment of a ratio of the signal representing a preceding high-resolution picture and the signal representing the instantaneous low-resolution picture and for then adding both adjusted signals achieves a gain of 3 dB in the prediction with the correct ratio, thus resulting in an improvement in the coding efficiency.

Abstract: In an encoding side, an estimate of input data is generated. An estimation error which is equal to a difference between the estimate and the input data is calculated. The estimation error is classified, thereby generating a category index indicative of a category corresponding to the estimation error. The input data is divided by a divisor, and a remainder of a result of the dividing is generated. The divisor is equal to a given value which is greater than a difference between an upper limit value and a lower limit value defining a range of the category. The category index and the remainder are encoded into corresponding codes which are outputted. In a decoding side, input data is decoded into a category index and a remainder. An estimate is generated from previous output data. A divisor is generated in accordance with the category index. An offset is generated in accordance with the divisor and the estimate. The offset is equal to the divisor multiplied by an integer.

Abstract: A sigma-delta modulator (50, 100) attenuates a frequency domain characteristic of a feedback signal to a first stage (60) of the modulator (50, 100) near f.sub.s /2, where f.sub.s is the modulator's (50, 100) clock frequency. The modulator (50, 100) thus virtually eliminates in-band tones which are characteristic of known sigma-delta modulators, without complex dithering schemes. In one embodiment, the sigma-delta modulator (50, 100) includes a two-tap finite impulse response (FIR) filter (80) within a feedback loop of the modulator (50, 100). The two-tap FIR filter (80) smoothes transitions at an output of a second stage (70) to provide the feedback signal to the first stage (60). This architecture is useful for either a digital-to-analog sigma-delta modulator (50) or an analog-to-digital sigma-delta modulator (100).

Abstract: A counter counts a clock signal. A multiplexer sequentially inputs digital input signals each having a plurality of bits in accordance with an output signal from the counter. A subtracter subtracts a quantized output signal delayed by an n-clock delay element from the input signal. An integrator integrates an output signal from the subtracter. The quantizer quantizes an output from the integrator. The n-clock delay element delays the output signal from the quantizer by n clocks and supplies the delayed signal to the subtracter. A demultiplexer sequentially outputs output signals from the quantizer in accordance with the output signal from the counter. This demultiplexer outputs signals in the input order of the multiplexer.

Abstract: For transmission and reception of an ADPCM stream in which each of signal components is represented by a predetermined number of bits, an ADPCM transcoder comprises a bit number determining device (43) for producing a bit number signal representative of first and second bit numbers one at a time to make the ADPCM stream carry a voice component with the first bit number and a data component with the second bit number as two of the signal components. The first bit number is less than the second bit number. Preferably, a sum of the first and the second bit numbers is not greater than twice the predetermined number to make one of the two signal components comprise the voice component and a less significant part of the data component. The first and the second bit numbers are calculated from a voice and a data optimum scale factor which can be calculated by a method similar to adaptive prediction. The bit number signal need not be carried by the ADPCM stream.

Abstract: A sensing system is provided for sensing the position of a manual gear select lever in an automatic transmission. The sensing system includes a plate member movable in response to movement of a shift lever and has a contact surface having a predetermined pattern of electrically conductive and non-conductive areas. An electrical sensing unit is mounted in the transmission so as to communicate with the contact surface of the plate member. A plurality of electrical contacts extend from the sensing unit to contact the conductive and non-conductive areas on the contact surface and generate binary codes in accordance with the position of the shift lever. Combinations of binary codes are provided for the operating modes and require at least two bit changes therebetween. In addition, transition codes are provided between each of the operating modes. The binary codes are provided to a transmission controller which determines the predetermined operating mode and transition modes therebetween.

Abstract: A separator provides peak value data and distance value data, a pair of registers respectively store multiple peak values and distance value data between peak values, a subsequent stage subtracts the series of multiple successive peak values to provide difference data, and divides the difference data by the distance value data to provide quotient data representative of a step size, and an interpolator provides a reproduced waveform by interpolating the peak value data and the quotient data.

Abstract: An apparatus for predictive coding processing a digital signal comprises a selective predictive filter, responsive to an input signal for outputting a predictive residual signal, an adaptive predictive filter, responsive to the predictive residual signal, for outputting an optimal predictive residual signal, and a re-quantizing unit means for re-quantizing and outputting the optimal predictive residual signal. The positions of the selective and adaptive predictive filters may be interchanged and the processing apparatus may be either feed forward or feed back type.

Abstract: A method and apparatus for enabling a real time video encoding system to accurately deliver the desired number of bits per frame, while coding the image only once, updates the quantization step size used to quantize coefficients which describe, for example, an image to be transmitted over a communications channel. The data is divided into sectors, each sector including a plurality of blocks. The blocks are encoded, for example, using DCT coding, to generate a sequence of coefficients for each block. The coefficients can be quantized, and depending upon the quantization step, the number of bits required to describe the data will vary significantly. At the end of the transmission of each sector of data, the method and apparatus of the invention compare the accumulated actual number of bits expended with the accumulated desired number of bits expended, for a selected number of sectors associated with the particular group of data.

Abstract: A multilevel encoding scheme for transmitted data that encodes data in a multilevel code wherein the amplitude of any transition is always exactly one level during any time interval. A single-level transition between any two adjacent levels during a time interval represents a logical "1"; no transition during a time interval represents a logical "0". In a specific embodiment, modulation is limited to three defined amplitude levels equally space in amplitude and encoding is according to a three-level code. A four-bit to five-bit encoding scheme may be used to distribute bits for minimizing d.c. offset. The input data is preferably further scrambled to minimize aberrations in the emissions spectrum of signal carried over unshielded media.

Abstract: Coefficient multipliers are inserted into feedback loops between an output of a delay unit and an input of an adder, and between an output of the other delay unit and the other input of the adder. Here, it is assumed that an input data supplied to an integration circuit is X(z), an output data supplied from the integration circuit is A(z), and an output data of a quantizer is Y(z). Then, the following equations are met.Y(z)=X(z)+Q(1-Z.sup.-1).sup.2 (1-.alpha.Z.sup.-1)where .alpha. is a coefficient of the coefficient multipliers.A(z)={X(z)+Y(z).multidot.F(z)-Y(z)}/F(z)F(z)=(1K.sub.1 Z.sup.-1) (1-K.sub.2 Z.sup.-1) . . . (1-K.sub.n Z.sup.-1)where K.sub.1 to K.sub.n are coefficients of real numbers meeting the relation 0<K.sub.1, K.sub.2, . . . , K.sub.n .ltoreq.1.

Abstract: A digital input signal is divided into signal components in plural frequency ranges by band division filters. The signal components thus obtained are divided in time into signal components in blocks in the respective frequency bands, and are also sent to a transient detector, which determines a transient state for each blocks. Changing an allowed noise level calculating circuit in response to the determined transient states, or any similar method, alters the quantizing bit numbers allocated to each block by an adaptive bit allocation circuit. The allocated bit numbers are altered depending upon the transient state of each block to improve the signal-to-noise ratio in blocks including a transient. Quantizing noise pre echo occurring before the transient, a phenomenon that is offensive to the ear, is prevented.

Abstract: An apparatus for compressing a digital signal in which a block of a spectral components in the frequency domain is divided in frequency into at least two sub blocks. The peak value for each sub block is determined, and the difference between the peak values is determined. Block floating is applied to each sub block individually when the difference between the peak values is above a fixed value. This prevents quantizing noise from being heard when the input signal is highly tonal.

Abstract: A method and system for compression and decompression. The system compresses data by calculating the differences between adjacent data values, identifying a plurality of frequently occurring differences, tracking the frequency of occurrence of the identified differences, generating a first encoding for the identified differences wherein the length of the encoding is based on the frequency of occurrence, generating a second encoding for the differences other than the identified differences, and for each calculated difference, encoding the calculated difference is identified difference and encoding the calculated difference using the second encoding when the calculated difference is not an identified difference to effect the compression of the data.

Abstract: A digital sigma-delta modulator comprises an adder, a quantizer, a subtracter, a filter circuit, and a limiter circuit. The adder adds input digital data and feedback data. The quantizer quantizes output data of the adder. The subtracter calculates a difference between output data of the quantizer and that of the adder. The filter circuit digitally processes output data of the subtracter to generate the feedback data. The limiter circuit is arranged in at least one position within an operation loop looping the adder, subtracter, and filter circuit and extracts (n-m)-bit data acquired by eliminating the significant m bit other than MSB from an n-bit data line.

Abstract: A delta-sigma modulator for a digital-to-analog converter includes a single adder (60) that has one input thereof multiplexed by multiplexer (62). Four shift registers (64), (66), (68) and (70) are connected in a serial fashion such that the data output by the adder (60) is input to the shift register (64) and the other input of adder (60) is connected to the output of register (70). In operation, the multiplexer (62) first selects the input data for input to the one input of adder (60) and selects the output of register (70) for the other input. This represents the first stage of integration wherein the accumulated value from a previous cycle is added to the present data. The output of the first stage of integration will be cycled through the registers for each overall cycle of the delta-sigma modulator. In the second stage of integration on the next clock cycle of the 4.times. clock, the multiplexer (62) selects the output of the register (68) for adding to the output of the register (70).

Abstract: A coding unit for coding an audio signal by using an adaptive orthogonal transformation and a coding method comprises calculating the sum total of power of an input audio signal in a time duration of an orthogonal transform length or over the length, adaptively controlling the minimum audible level as a threshold level corresponding to the power level on a frequency axis after the orthogonal transformation or on a time axis before the orthogonal transformation, excepting samples having a power level under the threshold level from orthogonally transformed samples and quantizing remaining samples. The threshold level of the minimum audible level is adaptively controlled corresponding to an observed level of an input audio signal. Even if the input audio signal has various power levels, it is possible to usually set the adaptively audible value (the threshold level), thereby effectively reducing a coding amount.

Abstract: A noise shaping circuit includes a first degree noise shaping arrangement in which a quantization error component at a first quantizer adapted for quantizing input signals is fed back to an input side, and in which a quantization error component at the first quantizer is fed back by a predetermined feedback circuit to an input of the first quantizer. The feedback circuit includes a synthesizing unit supplied with an error signal from a first quantization error output unit, a second quantizer for quantizing an output signal from the synthesizing unit, a second quantization error output unit for taking out a quantization error at the second quantizer, a transfer characteristic unit having predetermined transfer characteristics, and a differentiation unit supplied with output signals from the second quantizer. Error signals from the second quantization error output unit are supplied to the transfer characteristic unit, the output of which is supplied to the synthesizing unit.

Abstract: A differential code (DPCM) transmission system for an audio signal, in case higher frequency components thereof are dominant, every another samples of the input signal are alternately into two groups, in each of which differential coding effected, so as to maintain a dynamic range in higher frequency range; when a near instantaneously compressed DPCM signal is transmitted, coding errors caused by the compression are corrected by varying the difference between samples in response to the comparison between a locally decoded signal and the original signal; when the frequency components exceeding one fourth of the sampling frequency are contained in the input signal, successive 3 MSB's having a pattern "1, 0, 1" or "0, 1, 0" are corrected into "1, 1, 1" or "0, 0, 0" respectively; and in case 2 symbols of a tertiary code converted from 3 bits of a binary code are transmitted and restored, peripheral bit arrangement of a matrix having rows consisting of the first symbols of the converted tertiary codes and columns

Abstract: A signal modulation system for converting a plural-bit digital input signal to an encoded-bit digital output signal representative of an analog signal having a variable amplitude by employing delta-sigma modulation. The signal modulation system has a quantizer which quantizes the digital input signal and outputs it as the prescribed encoded digital ouput signal, and a control circuit portion which makes the quantizing step width in the quantizer vary corresponding to a control signal indicative of the amplitude of the analog signal to be represented. The quantizing step width is determined by a selection of respective sets of threshold values and quantizing values from memory as determined by the control signal. Comparators then produce comparison results between the digital input signal and each of the threshold values in the selected set, and a selector then selects one quantizing value in the selected set of quantizing values based upon the comparison results.

Abstract: A coding device comprises a coding circuit in which a range of values, which local decoded values are permitted to have is made narrower than a range of values, which input sample values are permitted to have when coding a differential value between an input sample value and its predictive value. A decoding device substitutes a decoded value to be subsequently decoded for a decoded value in which a gradient overload is produced when decoding a code provided by coding a differential value between an input sample value and its predictive value.

Abstract: A sound signal coding method and installation are disclosed, which method, usable particularly for transmitting or storing high quality audio signals in digital form, involves chopping the sound signal into blocks of samples and subjecting the samples of each block to time-frequency transform coding whose coefficients are transmitted in digital form, the reverse operations taking place at reception. At least the most significant coefficients of the transform of each block are subjected to predictive and adaptive coding using the stationary state of the signal over a duration greater than that of a block.

Abstract: A method and an apparatus for processing a digital signal by calculating a predictive error, then requantizing the predictive error thus obtained, and correcting the spectral form of requantization noise generated in quantizing the predictive error, wherein the spectral form of such requantization noise is approximated to that of the input signal while being suppressed in the lower frequency band thereof.

Abstract: A vector codebook with an ordered set of vector entries that satisfy a prearranged continuity requirement is used to encode signals. The continuity requirement specifies that consecutively considered vectors may not differ from each other by more than k elements, where k is less than the number of elements in the vectors. In one embodiment, two memories are maintained. One for determining the best codebook vector selection, and one for quantizing the input signal in accordance with the selected vector. Recognizing the possibility that the best ordering possible for a given set of codebook vectors can not satisfy the continuity requirement, the vector codebook arrangement of this invention is enlarged in such a case to include additional vectors that are interposed in the sequence of vectors and arranged to maintain the continuity requirement.

Abstract: A predictive coding device wherein a coding means for coding a difference between a sample value and a corresponding predictive value and outputting a coded code includes a memory storing at least one look-up table. The coding characteristics of the coded code can be changed, and at the same time, a control code associated with the coding characteristics is transmitted together with the coded code.

Abstract: The invention provides a method of encoding data, e.g. video signals at a lower bit rate for use in digital transmission or recording, and a method of decoding to perform inverse transformation of the encoded data. In the coding method, a block having a plurality of input data is used as an encoding unit. The input data in each block are predicted to obtain estimates thereof. Predictive errors, which are the difference between the input data and the estimates, are evaluated, and a maximum and a minimum of the predictive errors, SX and SN, are determined. A predetermined value larger than SX-SN is used as divisor data OU, which is used in dividing the respective input data to obtain remainders E for each block. The remainders E along with information on the predictive errors, i.e., SX, SN, and OU, are encoded and outputted. In the decoding method, information on a range for the predictive errors and the divisor OU are obtained by use of transmitted additional codes.

Abstract: In entropy, e.g. arithmetic, encoding and decoding, probability estimates are needed of symbols to be encoded and subsequently decoded. More accurate probability estimates are obtained by controllably adjusting the adaptation rate of an adaptive probability estimator. The adaptation rate is optimized by matching it to the actual probability values being estimated. In particular, the adaptation rate is optimized to be proportional to the inverse of the smallest value probability being estimated. Consequently, if the probability values being estimated are not small a "fast" adaption rate is realized and if the probability values being estimated are small a necessarily slower adaptation rate is realized.

Abstract: A method of encoding an audio signal onto and decoding an audio signal from a video signal wherein, in the encoding stage, successive portions of the audio signal are sampled, time compressed and inserted in analogue form into predetermined lines in the vertical interval of each field of the video signal. Also, distortion cancelling signals (which are generated as inverted forms of the time compressed audio signal portions) are inserted in analogue form into further predetermined lines in the vertical interval of each field of the video signal. In the subsequent decoding stage, the successive audio signal portions and the distortion cancelling signals are separated from the video signal, and associated ones of the audio signal portions and the distortion cancelling signals are added after inverting either the audio signal portions or the distortion cancelling signals in order that any perturbation present in both signals will cancel to zero.

Abstract: A predictive coding device includes: a limiter to limit an input value having a first dynamic range to a value within a second dynamic range narrower than the first dynamic range; a subtracter to calculate a differential value between an output value of the limiter and a predictive value; a quantization circuit to assign the same code to differential values which differ by a value which is equal to or larger than the second dynamic range and smaller than the first dynamic range; and a predictor to calculate a new predictive value by using an output of the quantization circuit. The quality of the code due to the limitation of the dynamic range is improved.

Abstract: A method and a system for compressing a delta modulation coded bit string by logically adding together, in mod 2 fashion, adjacent string bits to generate a transformed bit string which is then runlength encoded to provide a compressed bit string. A second embodiment of the invention uses an alternate bit complementation transform which is based on complementing every alterate bit of the bit string to provide a transformed bit string which is then runlength encoded to provide a compressed bit string. Decoding is accomplished by inversing the encoding methods.

Abstract: An adaptive quantizing device for use in a differential encoder which makes use of a device input signal variable in a predetermined dynamic range, a local decoded signal, and a local input signal from a prediction signal. The quantizing arrangement (12, 13) is provided for adaptively quantizing a difference between the device and the local input signals into a quantization output signal in accordance with a predetermined quantization characteristic so that the local decoded signal never exceeds the dynamic range even if the quantization output signal is accompanied by a quantization error of a maximum value. Preferably, the quantizing arrangement comprises a converting circuit (16) for quantizing the device input signal into a converted signal in accordance with a preselected quantization characteristic for use in making a single quantizer (13) adaptively quantize the difference into the quantization output signal.